Editable Body Object Rollout
 
 
 
Command entry:Select a Body Object. Modify panel Editable Body Object rollout

When you import an SAT file or convert an object in 3ds Max to Body Object format and then select it, the first rollout on the Modify panel is Editable Body Object. These controls allow you to perform available operations at the various sub-object levels, including flipping faces, welding and exploding (un-welding) edges, and more.

Body Object Sub-Objects

When you work with Body Objects (also Join Bodies and Body Cutter objects) in 3ds Max, you’ll find four sub-object levels available on the modifier stack: Operand, Edge, Face, and Element.

NoteFor Body Objects, the Edge, Face, and Element levels are also available as buttons at the top of the Editable Body Object rollout, but the Operand level is not.

Because Body Objects are not meshes but instead are defined procedurally, their structure differs from that of objects typically found in 3ds Max. For example, the entire circumference of a round object such as a sphere or cylinder can comprise a single face, as shown in the following illustration:

Left: Mesh cylinder has many faces.

Right: Body Object cylinder has only three faces: The top, bottom, and one side.

Following are descriptions of the different sub-object levels:

Operand

An operand is a component of an compound object created with Join Bodies or Body Cutter. You can transform Body Object sub-objects only at the Operand level.

The Operand level is available for all Body Objects, but is applicable only to Join Bodies and Body Cutter (that is, Boolean-type) objects. After combining objects using either of these object types, you can access the Operand sub-object level to move the sub-objects around, for example, to cut one shape out of another.

It is not possible to transform Edge, Face, or Element sub-objects at all. However, other operations are available at these levels, as detailed following:

Edge

At the Edge level, you can combine edges by welding them.

For best rendering results, it’s generally desirable to avoid unwelded, or “open” edges. You can see the number of open edges in the numeric display at the bottom of the Editable Body Object rollout. Also, open edges are drawn in blue in the viewports, as shown in the following image:

Edges are drawn in four different colors in the viewports to show their state:

1. Orange: Non-manifold edge (connected to more than two faces)

2. Blue: Open (unwelded) edge

3. White: Welded edge

4. Red: Selected edge

Incidentally, the orange non-manifold edge in the preceding illustration was obtained by joining two spheres using the Intersect + Merge Faces operation.

At the Edge sub-object level, you can weld specific pairs of edges by selecting them both (region selection is useful here) and then using Weld Selected on the Editable Body Object rollout. Or you can simply use Weld All to weld all open edges.

NoteIt’s important to distinguish between geometry edges and display curves that are used purely for visualizing the Body Object shape in the viewport. The latter are produced by adjusting the Viewport Display Settings Curve Display group Lines U/V settings, and cannot be selected. To see edges that can be selected, access the Edge sub-object level and press Ctrl+A (Select All).

Torus converted to Body Object format, displayed as Curves, with Lines U and V both set to 2. The geometry edges are red (selected), while the display-only curves are white.

Face

A face in a Body Object is the part of a surface surrounded by one or more edges. Unlike faces in mesh objects, a face in a Body Object is not necessarily planar. At the Face level, you can use all commands on the Editable Body Object rollout; a selection is necessary for the “Selected” commands.

Hair dryer (from Autodesk Inventor) with some faces selected

Element

An element of a Body Object is similar to an element of a mesh object: a collection of contiguous faces, physically isolated from the rest of the faces. Most typically, multiple elements are created when combining objects with the Attach command. Selecting an element is the same as selecting all of the faces in the element.

Modifiers and Body Objects

Following is a list of 3ds Max modifiers supported by the Body Object format. This means that you can apply and adjust any of these modifiers and then export the Body Object as regular solid geometry while maintaining full compatibility with the SAT file format. All other modifiers automatically convert Body Objects to mesh format.

TipBecause Body Objects are defined procedurally, deformation of large, complex objects can be time consuming. You might achieve faster results by first applying a Mesh Select modifier to the Body Object and deforming that. Also, for more-accurate viewport feedback, on the Modify panel set the Body Object’s Viewport Display Settings rollout Max Edge Len. % value to 2.0 or 3.0. When you have the desired results, turn off or delete the Mesh Select modifier before exporting the SAT file.

Interface

The Body Object has no sub-object history and can be edited in much the same way an Editable Mesh can be edited. Imported SAT files produce Body Objects. When you convert a 3ds Max or other Body Object into an Body Object, you lose the construction history for that object.

[sub-object levels]

Buttons for accessing the Edge, Face, and Element sub-object levels of the Body Object. The Operand level is available only from the modifier stack.

For details about Body Object sub-object levels, see Body Object Sub-Objects.

[# sub-objects selected]

This read-only field after the sub-object buttons shows the number and type of selected sub-objects.

Face Flip

Opens the Face Flipping/Visibility rollout with options for selecting duplicate faces, flipping faces, and setting face visibility.

Delete Sel

Deletes selected faces or elements.  You can also delete the selection by pressing the Delete key.

Weld Selected

Joins the selected faces or edges by combining coincident or nearly coincident edges into a single edge.

Weld All

Combines all coincident edges.

Explode Sel

Breaks up selected faces into separate elements that can be manipulated independently. Available only at the Face and Element sub-object levels, with at least one sub-object selected.

Explode All

Breaks up all faces into separate elements that can be manipulated independently.

Un-Trim

Removes the trimming of faces that are trimmed by curves.

Clean Edges

Removes edges that are interior to a face and do not trim the face.

Welding

Opens the Welding rollout with advanced options.

Information

The bottom part of the rollout displays information about the selected object. When joining faces or welding, use these values to determine the results of your operations.

# Edges

The number of edges in the object.

# Vertices

The number of vertices in the object.

# Open Edges

The number of open edges in the object.

An open edge is an unsewn edge with only one attached face. This is an important indicator for identifying closed solids. If the Open E display value is greater than 0, the volume is not closed. Also see the Volumes display, following.

NoteSometimes objects are meant to be surface models and thus have open edges.
# Faces

The number of faces in the object.

# Elements

The number of elements in the object.

# Volumes

The number of closed volumes in the object. If an object is a valid closed solid, it has at least one volume.

  • Welding Rollout

    The Welding rollout lets you specify how to to sew or stitch edges together. Welding is cumulative in that after you weld the result is kept and used again after you adjust the parameters. In general, start with a Tolerance Scale value of 1.0 (the default) and increase it.

  • Face Flipping/Visibility Rollout

    Use these controls for controlling the facing direction of faces in a Body Object. The Body Editable Object rollout Face Flip button toggles the Face Flipping/Visibility rollout, and you can also close the rollout by clicking Apply.