Export weights

When you smooth skin a surface, Maya creates one weight map per joint. The Export Weight Maps menu item lets you export all the weight maps at once.

Skin weight maps are exported based on the current UVs of the selected object. Skin weight mapping is relative to the UV parameterization of the skinned geometry.

Important: You cannot export or import skin weight maps to lattices.

If you want to export skin weights, it is best to assign UVs to your skinned geometry. If your skinned geometry does not have UVs, the results of the export can (depending on the complexity of the skinned geometry) be undesirable. If your skinned geometry has assigned UVs, and there is overlap in the UVs, the results of the export may be undesirable in the areas of overlap.

For information on creating UVs for polygonal or subdivision surfaces, see Mapping UVs.

Note: If you want to transfer skin weights based on spatial location and not UVs, see Copy smooth skin weights. With Copy Skin Weights, your source and target skinned geometry do not need to have the same UVs.

To export weight maps

Select the skin object(s). If objects are parented or grouped, select each object individually.
Select Skin > Export Weight Maps > to open the Export Weight Maps Options.
Set the options and click Export.
For most applications, only the Map Size X and Y options are useful. The other options are useful if you plan to use specialized map editing techniques. In most cases, the default option settings are appropriate.
In the Write Map file browser that appears, specify a path and name for a folder (or directory) that will be created to hold the map files, then click Write.
By default, Maya puts the folder name you specify under the sourceimages folder of your current project.
Click Yes when Maya lists how many maps will be written to disk, and prompts whether you want to proceed.
Maya places the image files, one per joint, in the folder you specified. For example:
```
jackie_back_root.iff
jackie_jaw.iff
jackie_left_ankle.iff
```
Maya also creates a weight map file named folder.weightMap in the same location as the folder you specified for the images (sourceimages by default).

The content of the weight map file defines the relationship between surface geometry and the image files. You can view and edit the contents of this file using a text editor. Maya uses the weight map file to import the images. When importing the weight map, the weight map file must be in the same location as the folder that contains the image files. See Import weights.