1193D Modeling, 2D Graphics, and Data Visualization
Offset is a valuable tool as well, especially with textures that have an alpha channel and may have had
the image placed just a little too close to the edges. Primarily, the Texture Offset will slide your texture
along the horizontal (U) or vertical (V) axis. If you turn on Select Face while doing the offset, you will see
the center of the texture moving back and forth when you run the spinners. It is always wise to make sure
that any texture with a transparent background, like a tree or bush, does not go all the way to the edge of
the image. It is best to leave a 4- to 6-pixel gap at the edge so you are not ddling too much with Offset
modication of the texture on your form.
6.8 SPECIALIZED TEXTURES: ANIMATED, TRANSPARENCY,
ANDBAKED LIGHTING WITH AMBIENT OCCLUSION
In the next 3 sections you will explore some of the more exotic forms of texture creation: animated textures,
textures with transparency, and textures that have the lighting in the scene added on their surfaces (baking)
with ambient occlusion.
6.8.1 TexTures WiTh animaTion
At times, you may want to create objects that have moving surfaces, things like water, spinning targets, ap-
ping wings, or whatever captures your imagination. There are several ways to produce these effects by the
use of simple scripts and special textures. The most basic way to animate a texture is to use a script to move
it around on the face of a prim. If you animate the offset, then the texture appears to slide across the surface,
just as water ows down a channel. Animate the rotation and you can have a spinning wheel image. If the
scale is animated, you can make a surface appear to “breathe” or inate.
If you want a cycling animated effect, perhaps a crackling re, then a series of ame images when played
in sequence can create a realistic effect. The initial texture is laid out in a specic grid so that the animate
texture script can nd that section of the texture and project each image in sequence. Figure6.17 illustrates
a texture that creates apping dragony wings. Each “frame” has the wings in a slightly different position,
and that creates the illusion of rapidly beating wings as the images are ashed on the surface of the prim as
rapidly as possible.
As you start to dive into animated texture creation and want to get scripts that create animated textures,
pay a visit to Robin Sojourner’s Texture Learning Exhibits on Living Tree Island in Second Life.
6.8.2 TexTures WiTh TransparenCy: TWo meThods for CreaTing Them
At some point in your virtual building career, you will need to make a texture that has transparency on it.
You may need to make a frosty window for your gingerbread house or a leafy branch for the new tree you
are building. There are several methods for creating these types of textures, and two of the most useful
ways are by using a 24-bit PNG le (easy; good for beginners) or making a TGA 32-bit le (less easy; good
for advanced graphics users). Torley Linden has a useful tutorial about the PNG method (http://youtu.be/
ekLIgpRHSq4) [6].
In textures that have varying levels of transparency, like a frosted window or a dragony wing, you may
need to utilize the alpha channel of a 32-bit Targa le. For more information on creating these kinds of
transparencies, check out Robin Woods’s excellent tutorial (http://www.robinwood.com/Catalog/Technical/
SL-Tuts/SLPages/WhiteHalo.html).
120 Virtual World Design
6.8.3 TexTures WiTh BaKed lighTing and amBienT oCClusion
When you get your nal mesh object build textured and lit in your 3D modeler, you will probably have the
option to add in Ambient Occlusion to the render process. Essentially, Ambient Occlusion is a rendering
process that calculates how the surrounding hemisphere of ambient light in the scene will be obstructed or
occluded by the existing objects or buildings. Once this is initiated, it creates a “dirt map” or soft-shadow
map on the entire scene. When this graduated tone is layered into the overall colored rendering of your
model, it can enhance the lighting effects, especially when you have soft daylight or indirect glow in the
scene. At this point, the shaded and lit texture can be unwrapped from the surface of the model and saved
as a at texture le or “Baked texture.” When the model is imported into Second Life or OpenSim, the
mesh model and its lit, shadowed, and colored baked texture comes with it and is reapplied to the surface.
3DModelers like 3DSMax and Blender offer Render to Texture (creating a baked texture), and UV unwrap-
ping features in their programs to help you create this effect.
All of this effort in prerendering or “baking” the shadows and lighting of Ambient Occlusion onto the
surfaces in your model is to encourage a speedy graphics performance for the visitor in your game or virtual
world. The less work the graphics card has to do with each texture, the smoother and faster the frame rate
will be for the visitor. If you have a model that you would like to view with Ambient Occlusion before you go
through the baking process, you can see how this effect looks inworld by turning on Advanced Lighting and
Ambient Occlusion in the Avatar/Preferences/Graphics menu (Figure6.18).
6.9 PROJECT: DESIGNING A DATA VISUALIZATION
ENVIRONMENT: YOUR 3D TIMELINE OR RÉSUMÉ
Virtual environments connect with external databases via specialized LSL (Linden Scripting Language)
functions. The introduction of real-time data visualization or data display within the 3D environment has cre-
ated some sensational results in the art and communication design sectors. This connectivity gives you many
interesting ways to explore a database and your relationship to data being collected in real time worldwide.
12
34
FIGURE 6.17 Screen grab from Second Life showing the texture needed for animated wings (top left) and its applica-
tion to a dragony vehicle. When the animation script is added, each wing picture (1–4) is displayed the face of the prim
sequentially for a fraction of a second, giving the overall effect of a uttering movement.
1213D Modeling, 2D Graphics, and Data Visualization
Texture Development: Ambient Occlusion and Pre-rendered Lighting
Ambient Occlusion shading on a grayscale model of the Alchemy Sims Warehouse
Colored textures applied to warehouse model: baked-in lighting with mid-range render setting
Under different render settings: Low (no advanced shading) to High (real-time shadows)
FIGURE 6.18 (See color insert) Screen grabs from OpenSim, Alchemy Sims Grid. The top panel shows the Alchemy
Sims Warehouse model with just the ambient occlusion lighting on while it was being built in Blender. In the middle
panel, the effect of ambient occlusion and the colored texture maps is displayed. In the bottom panel are three views of
the warehouse showing various render settings available inworld and how they can enrich the image.
122 Virtual World Design
The relationship between a virtual environment and the visible data it can represent creates opportunities for
the designer to express information in many new ways. Like great architecture, these spaces must be invit-
ing and understandable all at once. This “hands-on” project will give you the opportunity to practice your
building skills and to create a 3D “infographic” in a virtual space, which is based on your personal prole,
timeline, or CV (curriculum vitae; résumé).
To start this project, you will need your résumé or chronology. If you have one listed on LinkedIn, then you
can access the Visualize Me site (http://vizualize.me/) to create an instant graphic display of your work history.
The rst decisions you need to make are about the environment for your display. Here are some questions
to ask:
1. How will this be viewed by the visitor? For instance, will they walk among the display elements,
like an exhibit, or look down on it like a map?
2. What aspects of the exhibit structure and color palette will focus the eye towards your personal
timeline data.
3. How can you make your personal data come “alive” and display new, meaningful connections to
thevisitor?
Once you have answered these questions and broken down your personal history to some infographics,
download the content for this chapter from http://www.anncudworthprojects.com/Virtual World Design Book
Downloads and upload it into your avatar’s inventory. Let’s start building a timeline display of yourchronology.
6.9.1 maKe The Timeline Base
As shown in Figure 6.19, the decades of your lifespan are represented with a series of 10 m long boxes. Now
build a 100 m long box as the back wall, and stand it up behind the base sections. This represents a 100year
FIGURE 6.19 Screen grab from OpenSim showing the setup for the basic structure of the timeline. The base elements
are covered with a tiled texture to divide them into 10 increments—each block representing a decade. The back wall is
100m long, divided into 100 increments representing 100 years.
1233D Modeling, 2D Graphics, and Data Visualization
lifespan—may you live that long! Once those elements are built, add a grayscale grid texture to all surfaces.
Setthe horizontal repetition of the grid texture on the bases, so that it divides each decade box into 10 sections .
If you wish, each decade section may be color coded by changing the underlying color in the texture tab.
Onthe back wall, repeat the texture to match the base decade sections, making sure the textures align between
the wall and base sections. Once you have the base and back wall done, download the number models
(Numbers_0-9.dae) and add them along the timeline to enumerate the decades. Note, these meshes (made in
SketchUp) will come in as a linked set, so you will need to unlink them, and save them as separate numerals for
usage. With the standing numerals at the end of each decade box, there is a clear display of chronological order.
6.9.2 adding deTails
To add details along decade boxes, build some simple 3D content from prims like a graduate cap and wed-
ding bands to represent your education, and family. You can also upload the Icon_Briefcase.dae and the
Icon_Heart.dae meshes that you downloaded from the chapter’s content and add them to the timeline you are
building. You can see that in Figure 6.20. These can even be identied by the use of “hover text” (a simple
script that is widely available) if you desire. In addition to the heart and briefcase, there are two other icons:
the Icon_Information.dae, and the Icon_Pushpin for use in your timeline.
6.9.3 landmarKs and foCal poinTs
Looking at the structure you have so far, what do you see? 3D arrows (mesh model called Arrow.dae in the
content) were added to this timeline as shown in Figure 6.21, to draw the visitor’s eye toward information on
which they should focus. What can you add to the collection that personies you? In Figures 6.20 and 6.21,
some geographical shapes have been added to the back wall indicating international trips and countries
FIGURE 6.20 Screen grab showing the icons added along the timeline to represent your work, school, and personal
relationship chronology.
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