UV Mapping

Use

UV mapping is a means of mapping a texture image to a 3D model. Given a texture; for example, .jpg, .gif, the UV map allocates portions of the image to specific faces on the model. Often the default mapping is not optimal, and results in the image not lying on the model in the most useful way. Additionally, 3D objects that are VAMP-mapped may have many seams and overlaps that can make texturing difficult within most applications.

The UV Mapping tools allow you to apply UV mapping coordinates to selected objects to prepare them for further modification in SAP 3D Visual Enterprise Author. For example, once you have mapped a model, you can then use the Realight tool to simulate global illumination. The mapping tools are also used to pack UVs. Packing arranges UVs so that they fit efficiently onto a texture map and take up as much of the texture space as possible. The relax and knead options allow you to remove distortion from a model by spreading out the faces so that small faces are more prominent, making the model much easier to texture. Relaxing evens up the distribution of polygons on the map to make a model more evenly covered by the map.

In addition, you can map by element. An element is a group of connected faces in an object that is not connected to any other faces in the object. Certain types of models may be made up of multiple elements. The UV Mapping tools normally break an object up into mappable chunks based upon the angle between adjacent faces. The Map By Element option prevents the UV Mapper mapping across an element boundary. Because element boundaries are also sensible places to break up the UV mapping, using Map By Element can sometimes produce a better mapping for models.



Model showing normal VAMP UV mapping and mapping by element
The Pack tool is used to pack the polygon’s existing UVs using the settings established in the UV Mapping Settings window. The clump packing method can be used to pack the UVs multiple times until you achieve a useful result, as this method produces a different result each time a pack is initiated. If you use the rectangular or simple packing methods, you need only pack the UVs once as the same results are produced each time.

The Map, Relax and Pack tool is used to map the polygons into UV space, relax if required, and then pack the resulting UVs, all in one operation.

The settings in the UV Mapping Settings window determine how objects are mapped, how the UVs are packed, and whether relaxing of polygons is required.

Activities

Mapping, Relaxing and Packing UVs

  1. Open a 3D file.

  2. Choose Settings on the UV mapping toolbar. The UV Mapping Settings window will be displayed.

  3. Make your selections as required and choose OK.

  4. Select the objects for which you want to map and relax.

  5. Choose Map, Relax and Pack. The UVs are mapped to the selected objects.

Packing or Repacking UVs

  1. Open a 3D file.

  2. Choose Settings on the UV mapping toolbar.

  3. Make your required Packer selections and choose OK.

  4. Select the objects for which you want to pack.

  5. Choose Pack. The UVs are packed.
Related Information