Since for ever, documentation is a key part of 3D modeling. AutoCAD has several commands for creating projection, views, and sections from the model.
There are two commands for obtaining sections, the first one being more flexible and allowing the analyzation of 3D models.
The
SECTIONPLANE
command (alias SPLANE
) allows you to specify visual section cuts, composed of one or more planes. The command can be accessed on the ribbon, Home tab, Section panel, or on the Draw/Modeling menu bar. It can section solids, surfaces, and meshes.
The command prompts for the selection of a face or by specifying a point that defines the beginning of the section plane:
Command: SECTIONPLANE Select face or any point to locate section line or [Draw section/Orthographic]: Face selection
After selecting the face, a plane is placed coincident with that face. This new object is called a section object, it will include all models and can then be activated and moved. If we specify a point not on any face, a second point is requested and a vertical plane is created that passes through both the points. We may have several planes defined, but only one can be activated.
Options for this command are:
If we select a section plane and apply the shortcut menu, the access to several functions and related commands is provided:
The functions and commands are listed as follows:
LIVESECTION
command that activates or deactivates the section planeSECTIONPLANESETTINGS
command. This command controls the section parametersSECTIONPLANETOBLOCK
command. This command displays a dialog boxSECTIONPLANEJOG
command that allows adding vertices to the section line, thus creating a new plane with a 90 degree angleOne of the major utilities of this command is the section generation. This section is generated as an anonymous block that can be placed, for instance, on a layout. By applying Generate 2D/3D section on the section plane shortcut menu (or the SECTIONPLANETOBLOCK
command), a dialog box is displayed, with the following options:
In Section Plane, we can select the plane. In 2D/3D, we can choose between creating a planar 2D section or a 3D section. In Source Geometry, we can specify if the whole model is used for the section block generation, or if any specific objects are selected using the button below it. Destination specifies if the section is inserted in the drawing as a new block; it replaces an existing block, or is exported as a DWG or DXF file.
The button Section Settings calls the SECTIONPLANESETTINGS
command, allowing you to specify all section parameters. These are divided by 2D section / elevation block creation, 3D section block, and Live Section. The 2D section contains all the following five panels:
If we choose to insert a block, we press the Create button. A block is created and the command prompts for the insertion point, X scale factor, Y scale factor, and rotation. The block is inserted in the current UCS.
The SECTION
command (alias SEC
) is an old command for creating sections from 3D geometry, but very easy to apply. The result is a region or a curve for each cut object. The command prompts for the selection of 3D objects (can be solids, surfaces, or meshes):
Command: SECTION Select objects: Selection
By default, the section plane is defined by three points:
Specify first point on Section plane by [Object/Zaxis/View/XY/YZ/ZX/3points] <3points>: Point Specify second point on plane: Point Specify third point on plane: Point
With the same model, we are going to create some sections:
A3D_09_2.DWG
.SECTION
command create a section parallel to the ZX plane that passes through the middle of the assembly. The command creates four regions overlapping the geometry.SECTION
command, create a section parallel to XY plane that passes through the center of the bolt, and move the four new regions to the side:SECTIONPLANE
command we want a section coincident with the ZX plane, for instance, applying the Orthographic option and, then the Front option. The plane cuts the assembly in half.1
, Y scale 1
, and rotation 0
.A3D_09_2final.DWG
:While the SECTIONPLANE
command creates sections, the next command creates projections, or flattened views.
The FLATSHOT
command (no alias) creates a 2D representation of all 3D objects in the drawing by projecting all edges onto a plane perpendicular to the viewing direction. It can be applied to solids, surfaces, meshes, and regions.
First, we must set the viewing direction. Upon calling the command, a dialog box is displayed, including three areas and an option:
SECTIONPLANEBLOCK
command and specifies whether the view is inserted in the drawing as a new block, it replaces an existing block, or is exported as a DWG or DXF fileAs before, if we choose to insert a block, when pressing the Create button, a block is created. The command prompts for insertion point, X scale factor, Y scale factor, and rotation. The block is inserted in the current UCS.
We continue the model from Exercise 9.2, now creating some flattened and projected views.
A3D_09_3.DWG
.FLATSHOT
command, on the dialog box confirm Insert as new block, uncheck Obscured Lines Show, and check Include tangential edges. Upon pressing Create, specify an insertion point not far from the model for the new block and confirm scales and rotation.FLATSHOT
command with the same parameters. Place the new block on the same plane and near the previous block.A3D_09_3final.DWG
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