Chapter 11

3ds Max Rendering

Rendering is the last step in creating your CG work, but it is the first step to consider when you start to build a scene. During rendering, the computer calculates the scene’s surface properties, lighting, shadows, and object movement, and then it saves a sequence of images. To get to the point where the computer takes over, you’ll need to set up your camera and render settings so that you’ll get exactly what you need from your scene.

This chapter will show you how to render your scene using 3ds Max’s scanline renderer and how to create reflections and refractions using raytracing. In addition, this chapter will introduce you to the popular mental ray renderer and HDRI lighting workflow.

Topics in this chapter include the following:

• Rendering setup
• Motion blur
• Previewing with ActiveShade
• Cameras
• Safe Frame
• Render elements
• Rendering effects
• Raytraced reflections and refractions
• Bringing it all together: Rendering the rocket
• mental ray Renderer
• Final Gather with mental ray

Rendering Setup

In a manner of speaking, everything you do in CG can be considered setup for rendering. More specifically, your render settings and what final decisions you make about your 3ds Max scene ultimately determine how your work will look. In many ways, you should be thinking about rendering all along—especially if you are creating 3D assets for a game, where the 3D scenes are rendered in real time by the game engine. If you create models and textures with the final image in mind and gear the lighting toward elegantly showing off the scene, the final touches will be relatively easy to set up.

To set the proper settings, begin with the Render Setup dialog box.

Render Setup Dialog Box

The Render Setup dialog box is where you define your render output for 3ds Max. You can open this dialog box by clicking the Render Setup icon () in the Main toolbar, by selecting Rendering () a frame in your scene to check your work. The settings in the Render Setup dialog box are used even when the Render button is invoked; so it’s important to understand how this dialog box works. Figure 11-1 shows the Common tab in the Render Setup dialog box.

Common Tab

The Render Setup dialog box is divided into five tabs; each tab has settings grouped by function. The Common tab stores the settings for the overall needs of the render—for example, image size, frame range to render, and type of renderer to use.

In the Common Parameters rollout, you will find the most necessary render settings. They are described in the following sections.

Time Output

In this section, you can set the frame range of your render output by selecting one of the following options (as shown in Figure 11-2):

Single This option renders the current frame only. The frame range is set to Single by default.

Active Time Segment This option renders the frame range in the timeline.

Range This option renders the frame range specified in the text boxes.

Frames This option renders the frames typed in the text box. You can enter frame numbers separated by commas or specified as ranges, such as 3–13, to render only the specified frames.

Every Nth Frame This option is enabled when you are rendering more than one frame. It allows you to render every nth frame, where n is a whole number, so you can specify how many frames to skip.

Typically, you will be rendering single frames as you model, texture, and light the scene. The closer you are to final rendering, especially for scenes with moving cameras or lights, the more likely you will need to render a sequence of images to check the animation of the scene and how the lighting works. This is where the Every Nth Frame function comes in very handy. Using it, you can render every fifth frame, for example, to quickly see a render test range of your scene without having to render the entire frame range.

You should always test render at least a few frames of an animation before you render the entire frame range, because the smallest omission or error can cost you hours of rendering and effectively bottleneck production flow and get several people annoyed at you. This practice is a good habit to start. Whenever you want to launch a render of the entire scene, render at least one frame to check the output. If you have animated lights or cameras, use the Every Nth Frame option to test a few frames.

Area to Render This is where to go if you want to render only part of your frame. This is especially useful when you are testing the look of a single part of your frame, or even a single object, without having to wait for the rest of the frame to process. Here you can choose View, Selected, Region, Crop, or Blowup. For example, when set to Region, a re-sizeable box appears in your viewport as well as the Rendered Frame Window where you can select the region of the frame you wish to render.

Output Size

The image size of your render, which is set in the Output Size section (as shown in Figure 11-3), will depend on your output format—that is, how you want to show your render. Chapter 1, “Basic Concepts,” explains the popular resolutions used in production.

Resolution By default, the dialog box is set to render images at a resolution of 640 × 480 pixels, defined by the Width and Height parameters, respectively. This resolution has an image aspect of 1.333, meaning the ratio of the frame’s width to its height.

Image Aspect Ratio Changing the Image Aspect value will adjust the size of your image along the Height parameter to correspond with the existing Width parameter to accommodate the newly requested aspect ratio. Different displays have different aspect ratios. For example, regular television is 1.33:1 (simply called 1.33) and a high-definition (HD) television is a widescreen with a ratio of 1.78:1 (simply called 1.78). The resolution of your output will define the screen ratio.

Pixel Aspect Ratio Pixel Aspect affects the image because it actually changes the shape of the pixel from a square to a rectangle. This reflects how TV screens (standard definition, not HD) display images. When output is displayed on a TV screen, the image will be squeezed slightly horizontally. Therefore, renders are created a bit wider so that when they are displayed on a TV screen, they will appear normal. This is especially visible when you render a round object, as shown in Figure 11-4. On the left, the sphere is rendered with a pixel aspect of 1.0 (i.e., a 1:1 ratio). On the right, the sphere is rendered with a pixel aspect of 0.9 (i.e., a 0.9:1 ratio). However, when the sphere on the right is displayed on a standard TV, it will appear round and not stretched in this manner.

You hardly ever have to worry about pixel aspect ratios. They are mentioned only for those who may be outputting directly to DV tape or DVD. Luckily, in the Output Size section of the Render Setup dialog box there is a drop-down menu for choosing presets from different film and video resolutions. Custom is the default, and it allows you to set your own resolution. You can also select one of the preset resolution buttons. For DVD or TV output, you should select the NTSC D-1 (video) preset. For output to a DV tape, you should select the NTSC DV (video) preset. They both have a pixel aspect ratio of 0.9 to account for the TV “squeeze.” Of course, if you (or your client) are in Europe or in another place where the PAL standard is used, you will need to select the PAL equivalents of the aforementioned presets, because TV resolutions and frame rates differ internationally. For more on aspect ratios and frame rates, see Chapter 1.

The higher the resolution, the longer the scene will take to render. Doubling the resolution might quadruple the render time. To save time when you’re working with large frame sequences, you can render tests at half the resolution of the final output and render every fifth frame or so.

The image quality of a render also affects how long a render will take. In addition to turning down the resolution for a test, you can use a lower-quality render and/or turn off certain effects, such as Atmospherics (volume lights, for example, that simulate light cutting through fog). Quality settings are explained in the following section.

Options

The Options section (shown in Figure 11-5) lets you access several global toggles. Three boxes are checked by default. You can toggle the rendering of specific elements in your scene. For example, if you are using Atmospherics (volume light) or Effects (lens flare) and don’t want them to render, you can uncheck the appropriate box(es). This is a shortcut to turn off the effect or atmosphere.

Render Output

What good does it do to render a scene if you don’t save the files? When you are done setting up the dialog box for your image output, you need to tell 3ds Max where to render the images and what file format to use. Use the Render Output section as shown in Figure 11-6 to indicate that the file should be saved.

The image format can be selected to be a single image file or sequence of image files that form a sequence, or it can be a movie file such as a QuickTime. In fact, 3ds Max supports many image file formats. The most common movie format is arguably QuickTime. A sequence of frames is typically rendered to Targa or TIFF files.

Choosing a Filename

To specify a location and file type to render to, click the Files button to open the Render Output File dialog box shown in Figure 11-7. Select the folder to which you want to render, and set the filename. You can set the file type using the Save As Type pull-down menu.

Proper file naming is very important when you render a scene, particularly when you are rendering a sequence of images and have hundreds of frames. Saved images are usually identified by a filename, a frame number, and an extension in the form filename_####.ext—for example, stillife_0234.tif. This format is used in production facilities and accepted by most compositing programs, such as Combustion or After Effects.

When you enter the filename for an image sequence, you can include an underscore (the _ character) after the filename and before the frame number to help differentiate the two. This is especially useful if you use version numbers in your scene names. If you don’t use an underscore (or similar character) between the filename and frame number, your rendered image files can be confusing, as shown in the file list in Figure 11-8.

The extension portion of the image filename is a three-letter abbreviation that corresponds to the type of file you are rendering. By specifying a file format in the Save As Type drop-down menu, you automatically set the extension for the file in its filename. This way you ensure that you can identify the file type.

Image File Type

You can save your images in a wide range of formats when you render with 3ds Max. The format you choose depends on your own preference and your output needs. For example, JPEG (Joint Photographic Experts Group) files may be great for the small file sizes preferred on the Internet, but their color compression and lack of alpha channel (a feature discussed below) make them undesirable for professional film or television production work beyond test renders and dailies—meetings at which the day’s (or week’s) work on a production is looked at and discussed.

Furthermore, for two reasons it’s best to render a sequence of images rather than a movie file. First, you want your renders to be their best quality with little to no image compression. Second, if a movie render fails, you must re-render the entire sequence. With an image sequence, however, you can pick up where the last frame left off. The best file formats to render to are Targa and TIFF (Tagged Image File Format), though the decision can come down to personal preference. For example, OpenEXR is an incredibly robust file format to work with in compositing and is preferred by many professional artists.

These file formats enjoy universal support, have little to no image quality loss due to compression, and support an alpha channel. Almost all image-editing and compositing packages can read Targa- and TIFF-formatted files, so either is a safe choice most of the time. For more on image formats, see Chapter 1.

While we’re on the subject of image files, let’s look at what makes them up. Computer images are composed of red, green, and blue channels. Each channel specifies the amount of that primary additive color in the image. (See Chapter 1 for more on how computers define color.) In addition, some file formats can also save a fourth channel, called the alpha channel. This channel defines the transparency level of the image. Just as the red channel defines how much red is in an area of the image, the alpha channel defines how transparent the image is when layered or composited on another image. If the alpha channel is black, the image is perfectly see-through. If the alpha channel is white, the image is opaque. The alpha channel is also known as the matte. An object that has a transparency in its material, such as the wine bottle shown rendered in Figure 11-9, will render with a gray alpha channel.

The alpha channel is displayed in the Rendered Frame Window (Figure 11-10). You have seen this window display your test renders several times throughout this book.

To view an image’s alpha channel in the Rendered Frame Window, click the Display Alpha Channel icon. To reset the view to RGB (full-color view), click the Display Alpha Channel icon again. You can also see how much red, green, or blue is present in the frame by clicking any one of the red, green, and blue disc icons that are the Enable RGB Channel icons, as shown in Figure 11-10.

To save an image you like in the Rendered Frame Window, click the Save Image button. The Clone Rendered Frame Window button is quite useful in that it creates a copy of this window for you so you can compare a newer render to an older render without needing to save the images.

To copy a rendered image into another program, click the Copy Image icon, which will copy the image onto the Windows Clipboard. This image will then be available when you open other programs. You can paste it quickly into another application in fewer steps than before by using this feature.

Render Processing

When you click the Render button in the Render Setup dialog box, the Rendering dialog box pops up (Figure 11-11). This dialog box shows the parameters being used, and it displays a progress bar indicating the render’s progress. You can pause or cancel the render by clicking the appropriate button. Rendering can consume most, if not all, of your system’s resources. (It may also consume more than your system’s resources, which usually results in a crash!) Pausing a render will not let you access your scene in 3ds Max, but it will stop the process on your system momentarily so that you can tend to another PC task.

Assign Renderer

The Assign Renderer rollout (Figure 11-12) displays which renderers are assigned to your scene. Four types of renderers are available in 3ds Max by default (without any additional plug-ins installed) as shown in Figure 11-13:

Default Scanline Renderer The Scanline Renderer renders the scene as a series of horizontal lines.

mental ray Renderer This is a general-purpose renderer that can generate physically correct simulations of lighting and material effects.

VUE File Renderer The VUE File Renderer creates VUE (.vue) files, typically for natural environments.

Quicksilver Hardware Renderer Quicksilver is a renderer new to 3ds Max 2011 that engages the CPU and the graphics card’s processor (GPU) to quickly render your scene. This is useful for test renders and for quickly approximating how gaming engines may look.

VUE and Quicksilver are not covered in this book because they are advanced renderers; however, mental ray rendering is covered later in this chapter.

Rendering the Bouncing Ball

Seeing is believing, but doing is understanding. In this exercise, you will render the Bouncing Ball animation from Chapter 8, “Introduction to Animation,” to get the feel for rendering an animation in 3ds Max. Just follow these steps:

After the render is complete, navigate to your render location (by default it is set to the RenderOutput folder for the Bouncing Ball project). Double-click the QuickTime file to see your movie, and enjoy a latte.

Renderer Tab Basics

The Renderer tab, found in the Render Setup dialog box, has options that determine the look and quality of the render. The options that are displayed in this tab depend on which renderer you assigned to render your scene. We will cover the Default Scanline Renderer in the following sections and mental ray a bit later in the chapter. This rollout sets the parameters for the Default Scanline Renderer.

Options

Most of the features in Options (Figure 11-15) are used to make rendering a scene more efficient. If you want to do a quick render of an animation, for example, turn off Mapping and Shadows. You will still see the movement, but the processing will go faster.

Antialiasing

Aliasing is the staircase effect you see in an image just at the edge of a line or area of color, particularly when that edge is at an angle, as shown in Figure 11-16.

Antialiasing can smooth this stepped effect on diagonal or curved lines. It blurs and mixes the color values of pixels adjacent to the jagged line or curve, as shown in Figure 11-17. Turning off this feature will speed up your renders, but the quality loss will be noticeable.

Turning off Antialiasing disables the Force Wireframe setting. Geometry renders according to the material assigned to it even if Force Wireframe is turned on. Turning off Antialiasing also disables Render Elements. If you need to render elements, be sure to leave Antialiasing on (Figure 11-18).

Filters

Filters are the last step in antialiasing. You can use them to access different methods of calculating the antialiasing at the subpixel level in order to sharpen or soften your final output. You don’t need to worry about which filter to use until you have much more rendering experience under your belt. The Area filter, which is the default filter, will work great (Figure 11-19).

If you are curious about the different filter types, select a filter. A short description of it will appear in the box below the Filter Maps check box.

Motion Blur

With motion blur, a renderer can simulate how the eye or a camera sees an object in motion. When an object moves relatively fast, your eye (or a camera) perceives a blur on the object. Using motion blur for an animation can greatly enhance the fidelity of your render, although it adds more processing time. Use motion blur sparingly in most scenes. It takes a careful eye to choose the right blur amount for an object.

The Renderer tab in the Render Setup dialog box has two sections used for setting the type of motion blur you need.

Object Motion Blur

The Object Motion Blur section (shown in Figure 11-20) lets you access the motion blur settings.

The Object Motion Blur settings are as follows:

Duration (Frames) The higher the Duration number, the more blur you get. You can see the difference in the motion blur for the ball in Figure 11-21.

Samples This setting determines how many duration subdivision copies are sampled. The higher the Samples number, the better the motion blur quality.

Duration Subdivisions This setting determines how many copies of each object are rendered within the duration. The higher the Subdivisions number, the smoother the motion blur will look.

Setting the Duration very high and the Samples and Duration Subdivisions low will give you a ghosting effect that will kill the look of the motion blur. You will need to find the right balance to achieve a believable blur. Remember that less is more. Just a touch of motion blur may be all a scene needs.

Image Motion Blur

As you’ll notice in the Render Setup dialog box, Object Motion Blur is turned on by default. However, you still need to enable motion blur on a per-object basis; this means you have to toggle motion blur on for any object that you want to render with blur.

To turn on motion blur, select the object and right-click on it in a viewport. From the Quad menu, choose Object Properties. Select the type of motion blur (shown in Figure 11-22) you want, and then adjust the parameters in the Renderer tab.

The difference between Object and Image motion blur types can be seen in Figure 11-23. The bouncing ball on the left is rendered with Object motion blur, and the one on the right is rendered with Image motion blur. Both are rendered with the same Duration. The Image motion blur renders smoother, although it may not be as accurate because it is a smearing effect created after the object is rendered into the image. The Object blur renders the blur during the scanline rendering process itself.

For now, you only need to be concerned with the Duration parameter for an Image motion blur. This setting, as with the Object motion blur, sets the amount (and therefore the length) of the blur. Remember not to go overboard with motion blur. A little goes a long way.

Previewing with ActiveShade

ActiveShade is a fantastic 3ds Max feature that lets you interactively preview a render as you make changes in the scene. This is particularly helpful for texturing and lighting because the floating ActiveShade dialog box updates whenever you make a light or material change in the scene.

To enable ActiveShade, open the Render Setup dialog box (). At the bottom of the dialog box, click to toggle on the ActiveShade rendering, as shown in Figure 11-24. Pick your viewport, and either click the ActiveShade button in the Render Setup dialog box or click the Render button in the Main toolbar. The icon in the Main toolbar changes () as you switch from Production rendering to ActiveShade rendering.

You can also turn a viewport into an ActiveShade dialog box. Select the viewport where you want to enable ActiveShade, click on the middle Point-of-View viewport label, and from the menu choose ActiveShade, as shown in Figure 11-25.

That viewport will then become an ActiveShade viewport and will update a render every time you make changes to the scene. This helps keep the clutter of open dialog boxes to a minimum. You should switch off ActiveShade and enable Production before continuing with the rest of the chapter.

Cameras

Cameras in 3ds Max, as shown in the Perspective viewport in Figure 11-26, capture and output all the fun in your scene. In theory, the cameras in 3ds Max work as much like real cameras as possible. Hence, the more you know about photography, the easier these concepts are to understand.

The camera creates a perspective through which you can see and render your scene. You can have as many cameras in the scene as you want. However, it’s a good idea to position the camera you’re planning to render with where you want it for your final framing. You can use the Perspective viewport to move around your scene as you work, leaving the render camera alone.

Creating a Camera

There are two types of cameras in 3ds Max: Target and Free. A Target camera, much like a Target spotlight, has a Target node that allows it to look at a spot defined by where the target is placed (or animated). A Target camera is easier to aim than a Free camera because once you position the target object at the center of interest, the camera will always aim there.

On the other hand, Free cameras have only one node, so they must be rotated to aim at the subject, much like a Free spotlight. If your scene requires the camera to follow an action, you will be better off with a Target camera.

You can create a camera by clicking on the Cameras icon () in the Create panel and selecting either of the two camera types, as shown in Figure 11-27.

To create a Target camera, click in a viewport to lay down the Camera node, and then drag to pull out and place the Target node. To create a Free camera, click in a viewport to place it.

Using Cameras

A camera’s main feature is the lens, which sets the focal length in millimeters and also sets the field of view (FOV), which determines how wide an area the camera sees, in degrees. By default, a 3ds Max camera lens is 43.456mm long with an FOV of 45 degrees. This default lens will most likely meet all your camera needs, but in case you need to change the lens, you can use the Lens or FOV parameters to create a new lens using the spinner or by entering a value. To change a lens, you can also pick from the stock lenses available for a camera in its Modify panel parameters, as shown in Figure 11-28.

The most interactive way to adjust a camera is to use the viewport navigation tools. You can then place the camera while you see its field of view in that viewport. The Camera viewport must be selected for the viewport camera tools to be available to you in the lower-right corner of the UI. You can move the camera or change the lens or FOV. Chapter 3, “The 3ds Max Interface,” has a complete list of the tools in the “Viewport Navigation Controls” subsection. You can also change a camera by selecting the camera object and moving and rotating it just as you would any other object.

Talk Is Cheap!

The best way to explain how to use a camera is to create one, as in the following steps:

When the camera is set up, take some time to move it around and see the changes in the viewport. Moving a camera from side to side is known as a truck. Moving a camera in and out is called a dolly. Rotating a camera is called a roll. Also change the Lens and FOV settings to see the results.

Animating a Camera

Now that the camera is in the scene, let’s add some animation to the camera. Camera animation is done in the same way as animating any object. You can animate the camera or the target or both. You can also animate camera parameters such as Lens or FOV.

Clipping Planes

You can limit what your camera sees in a scene. For example, in a huge scene, you can exclude or clip the geometry that is beyond a certain distance by using clipping planes. This helps minimize the amount of geometry that needs to be calculated. Each camera has a clipping plane for distance (Far Range) and foreground (Near Range), as shown in Figure 11-30 and Figure 11-31, respectively. The near clipping plane will clip geometry within the distance designated from the camera lens.

You can also use clipping planes to create a cutaway look for a model. Set your near clipping plane to a specific distance into the object, and the object will render as if it were sliced, giving you a perfect cutaway look.

Likewise, if you find that a model or scene you have imported looks odd or is cut off, check to make sure your clipping planes are adjusted to fit the extent of the scene, especially with imported models.

To enable clipping planes, click the Clip Manually check box and set the distances needed, as shown in Figure 11-32.

Once you turn on manual clipping planes, the camera will display the near and far extents in the viewports with a red plane marker, as shown in grayscale in Figure 11-33.

Safe Frame

Because every TV is different, what you see on one screen may look somewhat different on a different screen. To help make sure the action of your scene is contained within a safe area on all TV screens, you can enable the Safe Frame view in any viewport. This will, as shown in Figure 11-34, show you a set of three boundaries in your viewport.

The Live area is the extent of what will be rendered. The Action Safe area is the boundary where you should be assured that the action in the scene will display on most if not all TV screens. Most TVs will display somewhere between the Action Safe and the Live areas. Finally, the Title Safe boundary is where you can feel comfortable rendering text in your frame. Because some TVs distort the image slightly at the edges, any text that falls outside the Title Safe area may not be readable. Although they are based on TV technology from years ago, these conventions hold true in professional production to this day. The Safe Frame areas are still good guidelines to use when framing your shot.

To view the Safe Frame areas in the chosen viewport, click on the viewport’s name in the upper left hand corner of the viewport to access the context menu, and then choose Safe Frame from the list.

Render Elements

The Render Elements tab is another tab in the Rendering Scene dialog box, and is shown in Figure 11-35. You might not need this feature as a beginner, but you will be surprised at the control you get when you render your scene into separate passes to composite later. As a beginner, you should concentrate on becoming familiar with rendering and lighting. As the months pass and you feel more comfortable rendering, you should discover that most CG is layered.

This means that separate passes are rendered and then layered or composited together with finer control in a program such as Photoshop for still images, and Composite, After Effects, or Nuke for image sequences. The ability to layer is another reason why rendering to image files is preferred over rendering to movie files.

However, you will need to understand compositing to be able to control and layer the elements back together.

Shadows and reflections are the main elements that you might consider rendering separately, especially when you are first learning. When these elements are separate, you gain a greater degree of control in compositing because you can affect the shadows or reflections any way you want (soften, color, transparency, etc.) as you composite them back on top of the image. For example, if you render a scene of a tree casting a shadow across a lawn, you will have to render the entire scene again if you decide to lighten the shadow color. If you have the shadow as a separate pass, you can very easily and interactively change the darkness of the shadow as you composite it in Shake, for instance.

The following list describes common elements to render:

Alpha Renders a black-and-white matte to be used in compositing. This is especially helpful when you need different mattes for different objects in your scene. In Figure 11-36, the chessboard is shown rendered in Alpha only.

Reflection Renders only the reflections so you can composite them separately onto the color render to have control over the amount of reflection in the final composited image, for example. Figure 11-37 shows the chess pieces’ reflections in the chessboard rendered as an element.

Refraction Renders only refracting elements in transparent or translucent objects, so they may be layered in the composite at a later time.

Self-Illumination Renders the incandescence of an object’s material separately, so its intensity may be controlled in composite.

Shadow Renders only the shadows cast in the scene into the alpha channel of the image. Figure 11-38 shows the chess pieces’ Shadow element. Keep in mind that you will have to render to an image format that has an alpha channel, such as TIFF.

Specular Renders only the highlights on an object’s glossy material. Figure 11-39 shows the specular highlights on the chess pieces. Look at how the nicks and scratches on the pieces are so noticeable in this element.

Z-Depth Renders a grayscale image that responds to the depth of a scene. The closer an object or a part of an object is, the whiter it renders. The farther from the camera an object or its parts are, the darker the render. This pass is then used in a compositing program, such as Combustion, to create a sense of haze or blur to add a depth of field to the image. Figure 11-40 shows a Z-Depth pass generated for the chessboard scene.

Now, let’s try rendering something. Follow along with these steps.

Rendering Effects

Rendering Effects offers a variety of special effects such as lens effects, film grain, and blur to add to your render. Rendering Effects allows you to create effects without having to render to see the results. They are rendered after your scene is rendered, and they are added to the rendered image automatically.

Lens Effect: Glow

You will add a glow effect to a light bulb hanging over the chessboard in a scene.

You will glow the Light Bulb object in the following steps:

Using Preview

Using the preview in the Environment and Effects dialog box as shown in Figure 11-49 (in the Effects tab), provides a much easier way to view the effects than rendering a frame does. You can select whether you want to preview all of the effects (All) in the scene or just the one you are working on (Current). Toggling Interactive updates the preview when you change the Effects parameters by opening a Render dialog box and updating it as you make changes. Enabling Interactive may cause your computer to slow down, so leave it unchecked and use the Update Effect button when you want to see an update.

Raytraced Reflections and Refractions

In this section, you will learn how to create realistic reflections and refractions in your renders. As you saw in Chapter 7, “Materials and Mapping,” you can apply an image map to an object’s material’s Reflection parameter to add a fake reflection to the object. To get a true reflection of the other objects in the scene, you will need to use raytracing methodology. There are essentially two ways to create raytraced reflections in a scene: by using a Raytrace map or by using a Raytrace material.

The Raytrace material is a more detailed solution; however, it can take twice as much time as using a Raytrace map, because the Raytrace material requires more calculation.

As you learned in Chapter 4, “Modeling in 3ds Max: Part I,” determining the level of detail you need for a reflective surface is important. There is no reason to use the Raytrace material for a reflection unless your camera is right up on the object. In many cases, the Raytrace map looks great and saves tons of rendering time. Keep in mind though, the amount of control you will have with a Raytrace map is significantly less than with the Raytrace material.

First you will try using the Raytrace material.

Raytrace Material

In the following steps, you will learn how to use the Raytrace material to create reflections in a scene with a fruit still life arrangement.

Creating the Raytrace Material

Tweaking the Render

The render will show the Raytrace material on the column reflecting like a flat mirror. It looks very convincing, but you may notice the jagged edges or artifacts around the reflected objects. What you’re seeing is aliasing in the reflections. The antialiasing filters set by default may not be enough. Clone this rendered image by pressing the Clone Rendered Frame Window icon (), which is found in the Rendered Frame Window toolbar, to make a copy of this rendered image in another window.

When the defaults aren’t enough, it is time for the heavy artillery: SuperSampling. SuperSampling is an extra pass of antialiasing. By default, 3ds Max applies a single SuperSample pass over all the materials in the scene. However, if a specific material needs more antialiasing, you can apply a separate SuperSample method to that material.

In the current still life scene, select the material slot for the column’s Raytrace material. Go to the SuperSampling rollout and uncheck Use Global Settings. Check Enable Local Supersampler. In the pull-down menu, choose Adaptive Halton, as shown in Figure 11-53.

The Adaptive Halton method performs well in this case. However, always try the regular patterns first; they tend to render faster. Render the scene, and you will notice a marked improvement in the quality of the reflections (Figure 11-54).

Raytrace Mapping

You can apply raytracing only to a specific map; you can’t apply it to the entire material. Because raytracing typically takes longer to render, this can save time. In this case, you will assign a Raytrace map to the Reflection map channel of a material to get true reflections in the scene, at a faster render time than using the material as you just did. Follow these steps:

Take a look at both the images created with reflections using the Raytrace material, and those created using the Standard material with the Raytrace map applied to Reflection. They look almost the same. This is good to know because it takes about half the time to render the Raytrace map. However, you will notice slightly better detail in the reflections created with the Raytrace material. You and the requirements of your scene will determine which reflection method works best in a particular situation. However, it’s good always to start with the Raytrace map to see if it creates enough detail without too much bother.

Refractions Using the Raytrace Material

Creating raytraced refractions in glass can be accomplished using the same two workflows as raytraced for reflections. The same conditions apply here. The Raytrace material renders more nicely, but it takes longer than using a Raytrace map for the Refraction map in a material.

Keep in mind that render times are much slower with refractions, especially if you add SuperSampling to the mix—so don’t freak out. Now you will create refractions using the Raytrace material:

You will notice a very nice wine glass render, with the bell pepper refracting through it slightly. Change the Index of Refr parameter on the material to 8.0, and you will see a much greater refraction, as shown in Figure 11-62. That may work better for a nice heavy bottle, but it is too much for the glass. An Index of Refr parameter between 1.5 and 2.5 works pretty well for the wine glass, particularly at the bottom of the glass where it rounds down to meet the stem.

Refractions Using Raytrace Mapping

Just as you did with the reflections, you will now use a Raytrace map on the Refraction parameter for the wine glass material. In the following steps, you will create another refraction render for the wine glass:

You can control the IOR through the material’s parameters in the Extended Parameters rollout, in the Advanced Transparency section, shown in Figure 11-64. Set the IOR to different numbers to see how the render compares to the Raytrace material renders.

The render will take quite some time to finish. The raytracing reflections and refractions slow down the render quite a bit. You can leave out the reflections if you’d like, but that will reduce the believability of the wine glass. You can also map a reflection as you did with the pool ball in Chapter 7; however, having true reflections will make the wine glass look much more realistic. When you raytrace both the reflection and the refraction, using the Raytrace material seems to be the better way to go.

Bringing It All Together: Rendering the Rocket

Now that you have some experience with the rendering workflow in 3ds Max, let’s take a quick look at rendering a short 45-frame sequence of the rocket. You will essentially take the rocket scene laid out in the previous chapter (with the atmospheric fog light through the window we set up). You’ll need to tweak a few of the scene settings, such as setting the rocket’s and environment’s materials to have raytraced reflections for maximum impact. You’ll also animate a camera move so you can render out a sequence you can pin to your refrigerator door. Let’s go!

Creating the Camera Move

We’ll begin by animating the camera.

Adding Raytraced Reflections

In Chapter 7, we used reflection bitmaps to fake the reflections on the rocket by using a bitmap to create the illusion of reflection. This technique usually looks very good, but there are circumstances where you need the reflections to look more accurate within the scene. This is when you use Raytrace map instead of a bitmap image. The Raytrace map calculates reflections as they work in the real world, reflecting the object’s environment. Of course, in order for raytraced reflections to work, your object needs to be in an environment, much like the rocket’s simple room. There has to be something around the object to reflect. To demonstrate this, we are going to add Raytrace to the rocket and the room.

The Rocket

To add raytraced reflections to the rocket, begin here:

We aren’t adding Raytrace to everything on the rocket, because Raytrace reflections take a lot more time to render. Don’t bother adding them to parts of the scene that won’t make a difference. Figure 11-72 shows a render of the rocket with the Raytrace map applied to the aforementioned materials.

The Room

In the room, the floors and the glass on the window should also have raytraced reflections, since reflections would look very good raytraced on these objects, especially with the camera move. Let’s start with the hardwood floor.

The floors have one issue with which we have to deal. The grooves between the wood panels should not have reflections; only the panels should reflect. We need to apply a mask to the reflections to block the Raytrace from the grooves in the floor. The floor already has a bump map to mark out the grooves, so that is what we will use as the mask as well.

Turning On the Environment Effects

Any Raytrace maps added to your scene can make the render time very long. If you are just trying to check an animation, it is wise to deactivate Raytrace while you do your test renders. To do so, open the Render Setup dialog box (press F10 or click on its icon in the Main toolbar) and click on the Raytracer tab, then go to the Global Raytracer Engine Options group, as shown in Figure 11-76. Just remember to turn it back on when your test renders are finished.

To round out the scene, we need atmosphere: Volume light was already added to the key light in the previous chapter, so we just need to turn it on. The Render Setup dialog box has a Deactivate button for atmospherics, so you can easily turn them on and off as you test render. To re-enable atmospherics in the render, go to the Common tab of the Render Setup dialog box and, under the Options section, check the Atmospherics box as shown in Figure 11-77.

Render the frame (Figure 11-78).

Outputting the Render

This scene has an animated camera, so doing a simple render just won’t do. We need to render out the entire 45 frames of the camera move. As you saw with the Bouncing Ball render earlier in the chapter, rendering out a sequence of images is done through the Common tab of the Render Setup dialog box.

In the Time Output section, click to select Active Time Segment: 0 to 45, as shown in Figure 11-79. The scene file you started with from the Red Rocket project will have its time segment set properly to 1 to 45. If you are working from your own scene file, however, you can either set the Active Time Segment in your scene to 1 to 45, or you can set the Range in the Render Setup dialog box manually to render from frame 1 to frame 45.

The resolution of the render is set in Output Size. The default resolution is 640 × 480.

On a good computer, this render takes about 1 minute 20 seconds per frame with environments turned on; that means the whole 45-frame sequence will take just over one hour to render. If you want to render faster and you don’t mind the render being smaller, you can render out at a smaller resolution. Half the default size is 320 × 240 and will cost you one-fourth of the higher resolution’s time (15 to 20 minutes or so) to render.

To change to the lower resolution, in the Output Size section, click on the preset button 320 × 240, as shown in Figure 11-80. Now it should take just about 20 seconds per frame to render.

Go to the Render Output section of the Render Setup dialog box and click Files to open the Render Output File dialog box shown in Figure 11-81. Typically, animations are rendered out in a sequence of images, but for simplicity’s sake, we will render out to a QuickTime movie as we did with the bouncing ball earlier in this chapter.

In the Render Output File dialog box (Figure 11-81), select where you want to store the rendered file, and pick a name for the QuickTime movie (Rocket_Raytrace.mov, for example). Then, in the Save as Type drop-down menu, choose MOV QuickTime File (.mov) and click Save. The Compression Settings dialog box will appear, as shown in Figure 11-82. Again, it is generally preferable to render to a sequence of images rather than a movie file; however, in this case a QuickTime movie file will be best.

In the Compression Settings dialog box, select Photo–JPEG for the compression type, set Frames per Second to 30, and set Quality to Best, just as you did with the Bouncing Ball exercise. You can set the Quality slider to a lower value for a smaller QuickTime file. But remember, this Quality setting applies only to the compression of the QuickTime file and not to the render itself. Click OK to return to the Render Output File dialog box, and click Save to return to the Render Setup dialog box.

Save your scene file, and you are ready to render! Just click Render in the Render Setup dialog box, and go outside to play catch with your kids or hassle your spouse or sibling into a needless argument for a little while. In about 20 minutes (or one hour if you chose to render at 640 × 480), run back inside and play the QuickTime file saved in the location you chose earlier. Then take a huge magnet and stick your monitor to your fridge door. Voilà! You are now ready to enter the world of rendering with mental ray.

mental ray Renderer

mental ray is a popular general purpose renderer that has fantastic capabilities. One of mental ray’s strengths is its ability to generate physically accurate lighting simulations based on indirect lighting principles. Indirect lighting is when light bounces from one object in a scene onto another object and casts light on it. In addition, incandescence or self-illumination from one object can light other objects in the scene. A direct light such as from an Omni light is not necessarily required.

mental ray’s reflections and refractions take on very real qualities when set up and lighted well. To enable mental ray, you must first select mental ray as the production renderer through the Render Setup dialog box.

Enabling the mental ray Renderer

You first need to enable mental ray to take advantage of its rendering features. To do so, in the menu choose Rendering () button for the Production entry shown in Figure 11-83. This will open the Choose Renderer dialog box (Figure 11-84).

In the Choose Renderer dialog box, highlight mental ray Renderer and then click OK. Once the mental ray renderer is assigned, you can make mental ray the default renderer by clicking the Save as Defaults button on the Assign Renderer rollout should you wish to continue using mental ray as your default renderer. Now, the Render Setup dialog box appears with the mental ray controls in tabs.

mental ray Sampling Quality

Once mental ray Renderer is enabled, click the Renderer tab in the Render Setup dialog box, shown in Figure 11-85. We will explore rendering with mental ray in a later section. The following is a brief explanation of the render settings most useful for you in your work.

Under the Sampling Quality rollout are the settings to control the overall image quality of your renders. The Minimum and Maximum Samples per Pixel values govern the amount of antialiasing of your render. You should be careful not to set the samples too high to avoid needlessly long render times. Sampling is the number of times mental ray will read and compare the color values of adjacent pixels to smooth the resulting render to avoid jagged lines.

These Minimum and Maximum Samples per Pixel values set the number of times mental ray will sample a pixel to determine how best to antialias the result. The higher the number, the finer the detail and the smoother the appearance of your rendered lines will be. These settings are exponential, so a large increase will yield a much greater quality but a much longer render time. What determines the exact sample level within the minimum and maximum range set by these attributes is dependent on the Spatial Contrast values for Red, Green, Blue, and Alpha.

Spatial Contrast values determine when mental ray turns up the number of samples in a particular region of the frame. If the contrast level from one pixel to its neighbor is below the threshold value, mental ray will turn up the number of samples for that pixel to render a higher-quality result for that specific area of the frame. Therefore, the lower the values set for the Spatial Contrast, the higher the sample rate will be (within the Minimum and Maximum levels set).

Rather than setting high sample rates with just the Minimum and Maximum Samples per Pixel, lower the Spatial Contrast values equally for RGBA to force mental ray to use values closer to the Maximum Samples per Pixel value only where it needs to do so.

For example, the image shown in Figure 11-86 was rendered in mental ray with a Minimum Samples per Pixel value of 1/16 and a Maximum Samples per Pixel value of 1 using a Spatial Contrast setting of 0.1 for all four RGBA values. You can see the jagged lines on the wagon’s white decal and edges quite clearly. When the Minimum Samples per Pixel value is changed to 4, the Maximum Samples per Pixel value is changed to 16, and the Spatial Contrast value is changed to 0.04 for RGBA, the render becomes much cleaner, with an acceptable increase in render times (Figure 11-87).

You can get essentially the same quality of render as shown in Figure 11-87 by setting Minimum Samples per Pixel to 16 and Maximum Samples per Pixel to 256 with a Spatial Contrast of 0.07 for RGBA, but with a much longer render time. Achieving quality without very long render times relies first on the Spatial Contrast values (lower is better), and then on the Samples per Pixel (higher is better).

mental ray Motion Blur

Enabling motion blur in mental ray is quite simple. The Camera Effects rollout, shown in Figure 11-88, is in the Renderer tab of the Render Setup dialog box.

To enable motion blur, simply check the Enable check box in the Motion Blur group. The Shutter Duration value governs how much blur is rendered (the higher the value, the more blur is rendered), and the Motion Segments and Time Samples values set the quality of the blur (higher values give better quality blur, with higher render times).

For practice, try re-rendering the Bouncing Ball exercise from earlier in this chapter with mental ray and motion blur to compare the results from the original scanline rendering.

Final Gather with mental ray

A popular feature in mental ray is indirect illumination—the simulation of bounced light (explained in the next section). In the tabs at the top of the Render Setup dialog box, click the Indirect Illumination tab. There are three rollouts:

• Final Gather
• Caustic and Global Illumination (GI)
• Reuse (FG and GI Disk Caching)

Final Gather

Final Gather is a method of mental ray rendering for estimating Global Illumination, or GI. In short, GI is a way of calculating indirect lighting. This effect allows for more accurate and physically real lighting simulations, where light can bounce in the scene and cast secondary diffused light on objects. This way, objects do not need to be in the direct path of a light (such as a spotlight) to be lighted in the scene. In short, mental ray accomplishes this by casting points throughout a scene. These light points are allowed to bounce from object to object, contributing light as they go, effectively simulating how real light photons work in the physical world.

This type of rendering can introduce artifacts or noise in the render. Finding the right settings to balance a clean render and acceptable render times is an art form all its own and is rather difficult to master. Only time and experience with Final Gather rendering will lead to mastery.

You will see how to use Final Gather later in the chapter. Figure 11-89 shows the Final Gather rollout. Some of Final Gather’s options, including how to deal with quality and noise, are explained here.

Basic Group

These are the most important parameters in the Basic section of the Final Gather rollout; they set the accuracy and precision of the light bounces, therefore controlling noise:

• FG Precision Presets slider—Sets the accuracy level of the Final Gather simulation by adjusting settings for the renderer such as Point Density, Rays per Point, and Interpolation. These settings alter how mental ray calculates the bounced light. The presets are Draft, Low, Medium, High, Very High, and Custom. (For Custom you enter your own values.) Use this slider first in setting how good your render’s lighting looks. Set it low for tests and increase the precision for final renders. In Figure 11-90, three spheres are rendered with a Draft setting for Final Gather, while Figure 11-91 is set to High. Notice Figure 11-91 is a cleaner render, and also shows more of the background and the spheres than does the Draft quality in Figure 11-90. However, going too high on the Precision slider may incur substantial render times. This slider will adjust the settings for several of the values covered in the following list.

• Multiplier/color swatch—This controls the intensity and the color of the indirect light being bounced. A value of 1.0 is the most physically accurate setting and is the default. Reducing this setting will lower the influence of the bounced light in your scene.
• Initial FG Point Density—This multiplier is one of the settings adjusted by the FG Precision Presets slider. Increasing this value will increase the quantity and density of FG “points” that are cast into the scene. For FG to work, the renderer casts these points into the scene. These points of light bounce within the scene and cast light on the objects they encounter. The higher the density of these points, the more accurate the bounced light appears. However, the higher the point density, the longer the render times. You may manually adjust this setting beyond the precision presets set by the slider.
• Rays per FG Point—This value is controlled by the Precision slider, but may also be manually set. The higher the number of rays used to compute the indirect illumination in a scene, the less noise and the more accuracy you gain, but at the cost of longer render times.
• Interpolate Over Num. FG Points—Interpolation is controlled by the FG Precision Presets slider as well as manual input. This value is useful for getting rid of noise in your renders for smoother results. Increasing the interpolation will increase render times, but not as much as increasing the Point Density or Rays values.

• Diffuse Bounces—The number of bounces governs how many times a point of light can bounce and affect objects in a scene before stopping calculation. If you set the bounces higher, the light simulation will be more accurate, but the render times will be costly. A Diffuse Bounces setting of 1 or 2 is adequate for many applications. Figure 11-92 shows the same render of the spheres as Figure 11-90, but with a Diffuse Bounces value of 5. This render is brighter and also shows color spill from the purple spheres onto the gray floor, though the grayscale image in this book will not demonstrate that adequately. You will find these two images compared in the color section of this book.
• Weight—This value governs how much influence the diffuse bounces have over the lighting solution in the scene. A value of 0 uses no contribution from bounced diffuse light in the scene. A value of 1 uses the full contribution of bounced diffused light, and is the default. This will control the amount of color spilled from one surface to an adjacent surface, such as the purple spill from the spheres in Figure 11-92 and in the color section.

Advanced Group

The Advanced group of settings gives you access to advanced ways of controlling the quality of your Final Gather renders. Some are described below in brief. You should experiment with different settings as you gain more experience with Final Gathering to see what settings work best for your scenes.

• Noise Filtering (Speckle Reduction)—The options are None, Standard, High, Very High, and Extremely High, and the default is Standard. This value essentially averages the brightness of the light rays in the scene to give you smoother Final Gather results. The higher the filtering, the dimmer your Final Gathering simulation result will be, and the longer your render times. However, the noise in your lighting will diminish.
• Draft Mode (No Precalculations)—This setting allows you turn off a good number of calculations that mental ray completes prior to rendering the scene. This will result in a faster render for preview and draft purposes.

• Max. Reflections—This value controls how many times a light ray can be reflected in the scene. A value of 0 turns off reflections entirely. The higher this value, the more times you can see a reflection. For example, a value of 2 allows you to see a reflection of a reflection.
• Max. Refractions—Similar to Max. Reflections, this value sets the number of times a light ray can be refracted through a surface. A value of 0 turns off all refraction.

The mental ray Rendered Frame Window

When you render a frame in 3ds Max, the Rendered Frame Window opens, displaying the image you just rendered. When you render with mental ray, an additional control panel is displayed under the Rendered Frame Window, as shown in Figure 11-93.

This control panel gives you access to many of the most useful settings in the Render Settings dialog box so you can adjust render settings easily and quickly.

Caustics and Global Illumination (GI) Rollout

Within the Caustics and Global Illumination (GI) rollout, you will find controls for various advanced mental ray lighting techniques. Caustics is a visual effect seen when light is reflected off a shiny or reflective surface and onto an adjacent surface in interesting light patterns. Caustics may occur also through a refractive surface, such as a glass of water, so that it indirectly lights an adjacent surface with focused light patterns.

The Global Illumination controls let you control the usage of photons by mental ray for generating Global Illumination. GI is another method of simulating bounced light that offers more options than Final Gather in the way the light is bounced. GI may also be used with Final Gather for a more physically real effect, but at the cost of high render times.

Because this book is an introductory book, we will not be covering caustics or GI.

mental ray Materials

For the most part, mental ray treats regular 3ds Max maps and materials the same way the Default Scanline Renderer does. However, a set of mental ray specific materials exists to take further advantage of mental ray’s power. In this book, we will examine the Arch & Design material used in mental ray.

The mental ray Arch & Design material works great for most hard surfaces, such as metal, wood, glass, and ceramic. It is especially useful for surfaces that are glossy and reflective, such as metal and ceramic.

To showcase these materials, we will re-texture a few parts of the red rocket from Chapter 7. Figure 11-94 shows the main material parameters for the Arch & Design materials. We will look at the features that we need for the rocket next.

The wheels will be done in the same way as in Chapter 7: by using the Multi/Sub-Object material and dragging the individually created materials to the selected polygons. The difference now is we will use the Arch & Design material instead. The wheel is divided into three materials: shiny red for the bolt, shiny white for the face, and bumpy black for the tire.

If you remember, when we first textured the wheels, we saved sub-object selections in Chapter 7. That will be useful here, too.

3ds Max Photometric Lights in mental ray Renderings

Now that you have had a basic look at the mental ray materials, let’s add some lights to the scene. The idea is to set up a light that makes it appear as though the sunlight is coming through the window, lighting the rocket and the room. In Chapter 10 we looked at lighting using Standard lights, but for this section we will use more advanced lighting tools like Photometric lights and the Daylight system.

Many of the parameters for Photometric lights are the same as or very similar to the Standard lights we looked at in Chapter 10. Here, we will show you the parameters that are specific to Photometric lights. Photometric lights simulate real lighting by using physically based energy values and color temperatures.

Photometric Light Parameters

Now let’s look in the Command panel at the Photometric light’s Intensity/Color/Attenuation rollout for our 75W light (Figure 11-107).

The Color group of parameters controls the color temperature of the light, which you can set either with a color or in Kelvin degree value just like with real-world photographic lights. In the drop-down menu, there are different color/temp settings. The default is D65 Illuminant (Reference White).

The Intensity group of parameters controls the strength or brightness of the lights measured in lm, cd, or lx at:

• lm (lumen)—This value is the overall output power of the light. A 100-watt general purpose light bulb measures about 1750 lm.
• cd (candela)—This value shows the maximum luminous intensity of the light. A 100-watt general purpose light bulb measures about 139 cd.
• lx at (lux)—This value shows the amount of luminance created by the light shining on a surface at a certain distance.

The Dimming group of parameters is another place to control the intensity of the light. When the Resulting Intensity box is checked, the value specifies a multiplier that dims the existing intensity of the light and takes over control of the intensity. Picking up from the last step in the previous exercise, let’s start to experiment with these values in the following steps:

3ds Max Daylight System in mental ray Renderings

The Sunlight and Daylight systems simulate sunlight by following the geographically correct angle and movement of the sun over the earth. You can choose location, date, time, and compass orientation to set the orientation of the sun and its lighting conditions. You can also animate the date and time to achieve very cool time lapse looks and shadow studies. In essence, this type of light works really well with mental ray and Final Gather. We will use it in the most basic way, using all of its defaults.

That is it. If you want to play around some more we recommend moving the light for a more dramatic shadow on the floor. Moving the light can have a dramatic effect on the luminance levels too, so be prepared to edit FG Bounces and Exposure Controls also. For this last render, shown in Figure 11-122 and in the color section of this book, we moved the light and changed the Exposure Value setting to 13.

3ds Max Lighting with HDRI in mental ray Renderings

High-dynamic-range images (HDRI) are used in CG to create more realistic scenes than the more simplistic lighting models used.

An HDRI is created when several photos at varying exposures are taken of the same subject, ranging from very dark (underexposure) to highlight only the brightest parts of the scene, to very bright (overexposure) to capture the absolute darkest parts of the scene. When these images (typically five or seven images) are compiled into an HDR image, you get a fantastic range of bright to dark for that one subject or environment.

How does that help you light? mental ray can create an environment map in your scene to which you assign an image, usually an HDRI. That environment map uses the brightness of its image to cast light in your scene.

The best type of image to capture for an HDRI is sometimes called a light probe. This is a picture of an environment such as the office reflected in a chrome ball shown in Figure 11-123. You can also take a light probe using a fish-eye camera lens capable of capturing a field of view of close to 180 degrees.

Figure 11-123 shows the middle exposure of five exposures taken of the same office. Figure 11-124 shows the range of photos from underexposed (dark) to overexposed (bright) that were used to compile this sample HDRI.

In the next exercise we will use an HDRI that is from the 3ds Max default HDRI library installed with the program. See Figure 11-125.

Open the Soldier_Mental Ray_Start.max file found in the Scenes folder of the mental ray Scene Files project on the companion web page. This scene has the final textured soldier and a tank modeled by Federico Esparza, a student of Randi’s, who was inspired by a tank design from the popular video game Warhammer 40,000: Dawn of War from THQ. There is a flat plane with some cracked dirt texture on it, and the file is set up with mental ray as the renderer. Nothing too fancy, but it’ll get the job done.

With the tank example, the HDRI environment map created an overall fill light for the scene, but also acted as a great reflection environment for the chrome accents on the tank. Adding the extra mr Area Spot light allowed you to create a sunlight for a key light that gave the scene highlights as well as defined directional shadows. HDRI environment maps are very good ways to insert complex lighting scenarios, but are often augmented with standard or photometric lights to really bring out the subject of the scene.

The kind of HDRI map you use will greatly change the effect of the lighting in the scene. Try out some of the other HDRI maps that come with the 3ds Max installation to see how they affect the scene and the reflections in the metal. All these tools and options make mental ray rendering extremely versatile and powerful. This is just the tip of the iceberg; there is much more to experiment with and gain experience on. We encourage you to download HDRIs as well as use different maps that come with the 3ds Max library to see how they change the lighting in any scene.

Summary

Rendering is the way you get to show your finished scene to the world, or whoever will stop and look. It enables the vector-created scene to be displayed in bitmap images or movie files on any monitor. Getting to this point in your scene takes quite a bit of work, as you can see, but once you see the results playing back on your screen, it all seems worth it. Nothing is more fulfilling than seeing your creation come to life, and that’s what rendering is all about. However, don’t consider the rendering process merely the last thing to do. Rendering may be the last step of the process, but you should travel the entire journey with rendering in mind, from design to models to animation to lighting. Always allow enough time to ensure that your animations render properly and at their best quality. Most beginners seriously underestimate the time needed to properly complete this step in CG production and don’t allow enough time for the render. Lighting and rendering are so important, as a matter of fact, that lighting professionals (who also handle rendering) are among the most sought-after and highest-paid workers in the entertainment CG field.

In this chapter, you learned the basics of rendering with Autodesk 3ds Max 2011. You began by learning about render output and the types of files to which you can render. You rendered the Bouncing Ball exercise from Chapter 8 and enabled motion blur for heightened effect. Then you learned about cameras and rendering separate passes with Render Elements. Additionally, you learned how to render glows and how to use raytracing to render true reflections and refractions in a scene. You put all that to good use in rendering the Red Rocket project that you’ve worked on throughout the book to a 1.5-second QuickTime file. Then you moved on to various exercises to explore Final Gather and HDRI when rendering with mental ray.

After you have rendered many more scenes, you’ll have a much better understanding of how to set up your scene from the very beginning to efficiently achieve a great result. It won’t hurt to go over the examples in this chapter more than once and try to render your own scenes in different ways.