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Creating Conform Objects

Conform compound objects mold one object over the surface of another. This compound object is useful for adding geometric details to objects, such as stitches to a baseball or a quilt.

The object that is modified is called the Wrapper object. The other object is the Wrap-To object. These objects need to be either mesh objects or objects that you can convert to mesh objects.

Cross-	Another way to mold one object over the surface of another is with the Conform Space
Reference	Warp. Find out more about this Space Warp in Chapter 38, “Using Space Warps.”

To create a Conform object, select an object to be the Wrapper object and select Create Compound Conform. To select the Wrap-To object, click the Pick Wrap-To Object button in the Pick Wrap-To Object rollout and choose one of the options below the button (Reference, Move, Copy, or Instance).

Caution	Shapes and splines cannot be used as either the Wrapper or Wrap-To objects, even if they are
	renderable.

In the Parameters rollout, shown in Figure 17-3, the Objects section lists both the Wrapper and Wrap-To objects. Name fields are also available for changing the names of both objects.

Figure 17-3: The Parameters rollout of the Conform object lets you define how the object is wrapped.

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The Wrapper Parameters section includes two adjustable values: Default Projection Distance, which is the distance that the Wrapper moves if it doesn’t intersect with the Wrap-To object, and Standoff Distance, which is the distance between the Wrapper and the Wrap-To object.

The Use Selected Vertices option causes only the selected vertices passed up the Stack to be moved.

Setting a vertex projection direction

The Parameters rollout also includes controls for specifying the Vertex Projection Direction settings. You can select to project the vertices based on the current active viewport with the Use Active Viewport option. If the view changes, you can use the Recalculate Projection button to compute the new projection direction.

You can also use the local Z axis of any object in the scene as the projection direction. The Pick Z-Axis Object button lets you select the object to use. After you have selected it, rotating this object can alter the projection direction. The name of the object is displayed below the Pick Z-Axis Object button.

Other projection options include Along Vertex Normals, Towards Wrapper Center, Towards Wrapper Pivot, Towards Wrap-To Center, and Towards Wrap-To Pivot. The Along Vertex Normals option sets the projection direction opposite the Wrapper’s normals. The other options set the direction toward the center or pivot of the Wrapper or Wrap-To objects.

Tutorial: Placing a facial scar

As an example of the Conform object, let’s add a gruesome scar to the face of our character. Using the Conform compound object, details like this scar can be a mesh object and still perfectly match the contour of the face object.

To create a facial scar using the Conform object, follow these steps:

1.Open the Facial scar.max file from the Chap 17 directory on the CD-ROM.

This file includes a face mesh with a mesh scar placed to its side. The face mesh was created by Viewpoint Datalabs.

2.Click the Select and Move button on the main toolbar, and select and move the scar to position it in front of the face mesh in the Front viewport.

3.With the scar selected, choose the Create Compound Conform menu command.

4.Click the Pick Wrap-To Object button, and click the face mesh. Select the Move option.

5.Under the Parameters rollout, select the Use Active Viewport option and make sure that the Front viewport is active. In the Wrapper Parameters section, set the Standoff Distance value to 1.0.

Figure 17-4 shows a close-up of our surgery in the maximized Perspective view.

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Figure 17-4: A patch grid being conformed to the front of a face object

Creating a ShapeMerge Object

The ShapeMerge compound object enables you to use a spline shape as a cookie cutter to extract a portion of a mesh object. This button is enabled only if a mesh object and a spline exist in the scene. To use this object, select a mesh object and click the Pick Shape button in the Pick Operand rollout, and then select a spline shape. The shape can be a Reference, Move, Instance, or Copy.

The spline shape is always projected toward its negative Z axis. By rotating and positioning the spline before selecting it, you can apply it to different sides of an object. You can apply multiple shapes to the same mesh object.

The Parameters rollout, shown in Figure 17-5, displays each mesh and shape object in a list. You can also rename either object using the Name field. The Extract Operand button lets you separate either object as an Instance or a Copy.

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Figure 17-5: Use the Parameters rollout for the ShapeMerge compound object to cut or merge a shape.

Cookie Cutter and Merge options

The Operations group includes options for cutting the mesh, including Cookie Cutter and Merge. The Cookie Cutter option cuts the shape out of the mesh surface, and the Merge option combines the spline with the mesh. You can also Invert the operation to remove the inside or outside of the selected area.

Like the Boolean Subtraction operations, the Cookie Cutter option can remove sections of the mesh, but it uses the area defined by a spline instead of a volume defined by a mesh object. The Merge option is useful for marking an area for selection. Figure 17-6 shows a ShapeMerge object with the Cookie Cutter option selected.

Note You can use the Merge option to create a precise face object that can be used with the Connect object.

The Output Sub-Mesh Selection option lets you pass the selection up the Stack for additional modifiers. Options include None, Face, Edge, and Vertex.

Note To see the backsides of the faces, right-click the object, select Properties from the pop-up menu, and disable the Backface Cull option.

Tutorial: Using the ShapeMerge compound object

When outlined text is imported into Max, it typically contains letters that have shapes within shapes. For example, the letter p, when outlined, includes the outline of the letter p and a circle shape to denote the interior section of the letter. When outline text like this is converted to a mesh object, both the letter outline and its interior section are covered, making the text illegible. You can use the ShapeMerge compound object to remedy this tricky situation.

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Figure 17-6: A ShapeMerge object using the Cookie Cutter option

In Chapter 3, “Working with Files and XRefs,” you encounter an example where the logo for the fictional Bugs Head Software company was imported from Illustrator. Before this logo can be extruded, you need to do some work involving the ShapeMerge object.

To use the ShapeMerge object to remove the center area from an extrusion, follow these steps:

1.Open the Bugs Head Software logo.max file from the Chap 17 directory on the CD-ROM.

This file is slightly different from the file found in Chapter 3. For example, the bug’s mouth has been made into a closed spline.

2.Click away from the objects to deselect all the objects, and select (while holding down the Ctrl key) the two interior splines of the letter B that make up the bug’s left eye. Open the Display Floater by choosing Tools Display Floater, and click the Selected button under the Hide column to hide the interior portions of this letter.

3.Select the bug’s head shape again. Then select the Create Compound ShapeMerge menu command.

4.Set the Operation to Cookie Cutter, and click the Pick Shape button in the Pick Operand rollout with the Copy option. Select the mouth and the letters used for the eyes and nose. Click the Select Object button on the main toolbar to exit pick mode and to deselect the bug’s head.