Posing >
Troubleshoot posing

The following table lists common problems related to posing and possible solutions:

Problem/Error Message | Possible Solution
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Rotating a model component at a joint causes the component to either collapse or bulge in an undesirable way. | This indicates that the region of influence needs to be adjusted on the joint. While Mudbox sets the pivot location automatically whenever a joint is created, it may need to be modified using either the Weights tool or Move Pivot tool so the affected areas appear more natural. For more information, see Adjust a joint’s region of influenceand Adjust a joint’s pivot location The Sculpt tools can also be used to quickly perform fine adjustments and corrections on a model. This may be quicker than spending a lot of time adjusting the weights provided your model component deformation is close enough. For example, the Smooth tool can quickly correct unwanted bulges, and so on.
More of the model deforms on the opposite side of the joint than I expect. | The weighting is symmetrical by default on either side of the joint. If you drag the Weight Vector quite far from the joint when creating it, the default region of influence might be larger than you expect. Either recreate the joint with a more abrupt falloff, or adjust the weight color. Another cause for unbalanced deformation on the joint might be the unsymmetrical falloff curve that was active when the joint was initially created. Recreate the joint using a different falloff curve setting or adjust the weighting. For more information, see Adjust a joint’s region of influence.
Some vertices move unexpectedly when the model is posed. | Check the weights values in those areas in relation to the joint. If they have weight color on them, they are likely to be affected whenever the joint is posed to some extent. Temporarily assigning a darker material color to the model can aid in obtaining more contrast for the joint weight color so you can see any areas with weighting. For more information, see Adjust a joint’s region of influence.
Joint positions do not match the imported model’s current position when the model is imported to Mudbox. | In some situations, a model may have to be placed into its bind pose position prior to export as an FBX file before importing to Mudbox. The model can subsequently be posed using the joints and weight settings once it is in Mudbox.
Joint weighting does not appear to blend smoothly when a model with joints is imported and posed in Mudbox. | Mudbox only supports four joints influencing a given vertex (the four strongest joints) when importing a model with existing joints from another application. The influence of remaining joints is ignored, which can result in un-smooth joint transitions when posing. To help compensate for this, the weighting for imported joints can be smoothed on import by turning on the Smooth Joint Weights preference (Windows > Preferences > FBX > Smooth Joint Weights). For more information, see the FBX import preferences.
A separate model component that was parented into the skeleton (joint) hierarchy in Maya is not transforming along with other models when it is imported and subsequently posed in Mudbox. | Joint hierarchies where meshes have been parented into a joint hierarchy are not supported by Mudbox. To compensate for this, you can fully weight the mesh to the joint is was the child of.
Some areas of the model are invisible when using the Pose tools. This occurred after I imported a model with an existing skeleton hierarchy into Mudbox from another application. | Portions of a mesh may not display in the 3D View if the number of joints exceeds a specified amount. This limitation only affects the mesh when using the pose tools, and is not apparent when sculpting or painting. The mesh can still be posed but you’ll need to select either a paint or sculpt tool to view the entire mesh. The maximum number of joints a mesh can have before display limitations occur is dependent on your computer’s graphics card: NVidia: 256 joints; ATI: 75 joints.