ShrinkWrap

The Deformation->ShrinkWrap command in the Model module allows you to shape or "shrinkwrap" a model (curve, polygon mesh, patch, or NURBS surface) to conform to the surface of a target object that can be a polygon mesh or patch object. You can control the direction of the shrinking, as well as the amount of shrinkage. You can apply the effect to the entire model, or only to tagged points.

ShrinkWrap is typically used to:

• Create a metamorphosis between two dissimilar objects by shrink-wrapping another object (such as a large patch or NURBS sphere or a subdivided cube) to the two objects and then applying the SOFTIMAGE 3D shape interpolation on the results.
• Project a curve path onto a surface, such as an uneven terrain or a model of a character. This lets you easily create paths that are guaranteed to lie on the surface.
• Create seamless models. A large patch or NURBS surface can be shrunk to a model composed of several objects, such as a head modelled from several scaled and deformed spheres. This creates a simpler model consisting of a single patch or NURBS surface without seams.

The Deformation->HrcShrinkWrap command in the Model module allows you to shrinkwrap using a hierarchy of objects. The Effects->AnimatedShrinkWrap and Effects->HrcAnimShrinkWrap commands in the Motion module are the animated versions of this effect.

Procedure

1. Create the following three models:

• The target object: this is the polygon mesh or patch object toward which the points "shrink." You cannot use a NURBS object as a target object.
• The outer wrapper model: the points of the outer wrapper model "shrink" until they reach the target object. The outer wrapper model can be a polygon mesh, curve, patch, or NURBS surface.
• The inner wrapper model: this model must have the same number of points as the outer wrapper model because points of the outer wrapper move toward the corresponding points of the inner wrapper. This determines the direction of "shrinking" for each point of the outer wrapper.

2. Choose the Deformation->ShrinkWrap command. The Shrink Wrap dialogue box is displayed.
3. Set the parameters as desired.
4. Pick the target object, the outer wrapper, and then the inner wrapper.

Parameters

Shrink Wrap Factor

Determines how far the points on the outer model move toward the target object: a value of 1 moves the points all the way to the surface of the target, a value of 0.5 moves them half way there, and so on.

Emboss Factor

Determines the degree in which the resulting model is embossed. This parameter is for advanced use.

ShrinkWrap Tagged Points Only

When this option is selected, only the tagged points on the outer model are moved.

Note:
This option is available only in the Shrinkwrap and AnimatedShrinkWrap effects (it cannot apply to hierarchies).

Spatial Subdivision (For Efficiency Only)

XDiv, YDiv, and ZDiv

These options allow you increase the speed and efficiency of the effect calculation by specifying division factors for x, y, and z. If the target object has a large number of points, the speed of the calculation may be increased by increasing these values.

Last updated 08-apr-1998