Unwrap

The Deformation->Unwrap command in the Model module allows you to distort a model as a guide for cylindrical or spherical 2D texture mapping. Unwrap distorts the selected model into a rectangular region in the xy plane. This image can then be used as a guide for distorting a 2D texture map. In this way, features of the texture may be accurately aligned with features of the model. For example, Unwrap can be used as a guide for distorting a scanned image of a head to match features on a model of the head when textured.

Procedure

1. Create a model.
   
   The model should be located at the origin (global centre) and is "pointing" toward the negative x-axis.
   
   
2. Choose the Deformation->Unwrap command. The Unwrap dialogue box is displayed.
3. Set the parameters as desired.
4. Follow the prompts for selecting the model.

To make use of the result when texturing, the new (deformed) model must be rendered and used as a guide in creating or deforming a texture map. There are several ways to do this: one technique is described here.

Create a grid of the same width and aspect ratio indicated in the dialogue box, and rotate it on the xy plane. This indicates the border of the image. The simplest way to "render" this now is to take a snapshot (screen grab) of the Front window of the grid and distorted model.

You could also centre the camera on the grid, positioned far away and zoomed so that the grid fills the Perspective window exactly. This may then be rendered in hidden line, or guide curves drawn by you may be converted to faces and rendered.

Parameters

Unwrapping Type

The type of mapping that is used to texture the model. Select either Spherical or Cylindrical.

Resulting Width

The desired width, in SOFTIMAGE units, of the deformed model that is produced.

Resulting Aspect

The desired aspect ratio (height to width) of the resulting model. Set it to the aspect ratio of the texture image.

Last updated 08-apr-1998