User-defined UV mapping

You can map UV texture coordinates by specifying user-defined planes for UV projection using the Load Projection option within the Automatic Mapping feature.

The Load Projection option uses a polygon object that you specify from the current Maya scene. The object can form a cage around the object or be comprised of separate faces that intersect each other at its center. The Automatic Mapping projection manipulator updates when a user-defined object is specified for projection.

Criteria for user-defined projection objects

In addition, it is useful to know the following:

To load a user-defined polygon object for use with Automatic Mapping

  1. Select a polygon object in the scene view that you want to project UVs onto.
  2. Select UV > UV Editor to open the UV Editor.

    The existing UVs for the object appear in the UV Editor’s 2D view.

  3. From the Modeling menu set, select UV > Automatic > .

    The Polygon Automatic Mapping Options window appears.

  4. In the Polygon Automatic Mapping Options window, turn on the Load Projection option, then do one of the following:
    • Specify the object in your current scene you want to have loaded as the projection object by typing its name in the Projection Object box.
    • Select the object in your current scene that you want to have loaded as the projection object, and then click Load Selected. The name of the object appears in the Projection Object box. See "Criteria for user-defined projection objects" above.
  5. Click Project or Apply to execute the Automatic Mapping feature.

    The automatic mapping projection manipulator appears centered about the object in the scene view with blue projection planes that correspond in orientation to the planes of the Load Projection object you specified. That is, if the Load Projection object has 8 planes in various angles of orientation, the projection manipulator displays similarly.

    Note: In some instances, the Load Projection object may cause the planes on the automatic mapping projection manipulator to appear unexpectedly offset or skewed from the object you’re projecting on. This UV offset is based on the original UVs for the Load Projection object and doesn’t affect the quality of the projection.

    You can unitize the UVs for the Load Projection object prior to projection so its UVs reside in the 0 to 1 texture space. While this will make the projection manipulator appear more centered about the polygon object it may not provide the UV mapping results you were expecting as the UVs will be projected similar to having explicitly specified the Overlap feature.

  6. Translate, rotate, or scale the manipulator as required to achieve the UV projections you require. The projected UVs appear in the UV Editor. You can observe them update within the UV Editor whenever the manipulator is moved within the scene view.

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