The current AvaStar test version is avastar-1-1-1012_blender-2-65. (It is proprietary so no link)
There is a problem getting the knees to work right with Fitted Mesh. Gaia Clary posted a possible work-around in the SL Forum.
I found similar issues when i worked with a non default shape in Avastar. Here is what might (possibly) help:
- Update to Avastar-1008 or newer (from the test versions folder).
- Create a default Avastar
- Adjust your pants to the default Avastar!
- “Attach to Armature” in the skinning panel (on the tool shelf)
- Use the “Fitted Mesh” Preset button (in the same panel)
- Attach sliders (in the same panel)
- Update the Avastar shape to your personal shape (Load shape in the Armature’s Object properties panel)
- Now you can see if the problem still exists. In that case you possibly can improve the weights (You currently have to use the Refresh button (in the same panel) to recalculate the shape after applying the weight changes.
It is important to adjust the mesh to the default Avastar character and add the personal shape after you have attached the pants to the armature!
BTW: When working on attachments for both genders, i found that switching between male and female during the skinning process does not work well with fitted mesh (although i thought the technique could handle this case). I am not sure if that is a flaw in Avastar or in the Fitted Mesh in general. Maybe it is anyways better to create 2 versions of your attachments in that case.
A newer Blender 2.70 RC is out: Blender 2.7 March 5 or 6 RC.