How to rig/export fitted mesh with joint changes in Blender 2.7

[DragonWhisperer]

After much trial and error, I finally understand how to get a working fitted mesh avatar with custom joint positions uploaded. Shape sliders didn't accomplish the bone changes I wanted, so I hope this helps if you're in the same boat.

Here's a list of guidelines that work for me (using the .blend file from Linden Labs):

1. Even though the new collision bones (RIGHT_PEC, LEFT_PEC, UPPER_BACK, etc.) are included in the .blend file, only the BUTT, LEFT_PEC, RIGHT_PEC need attention if you want to have any bounce or wiggle. I'll refer to these new bones as cBones.

2. You can weight to the mBones like you always have, so unless want your custom avatar to use body shape sliders, you can delete all the new bones, save the three that use physics.

3. Delete the custom properties from all mBones. SL will handle those bones without any under-the-hood tinkering. We actually only need the custom sbx_location_x, sbx_location_y, and sbx_location_z values for positioning the remaining three cBones in our Blender rig.

4. Do not alter the custom properties for BUTT, LEFT_PEC, RIGHT_PEC. Ever.

5. SL will position all the cBones to match the mBones upon upload.

6. If either mPelvis or mChest are not in the exact same location in your custom rig as in the default rig, you need to manually position the cBones so that your mesh will bind to them where SL will render them.

                For example:  In your new rig, you moved the mChest bone by -0.15 along the x-axis and by +0.3 along the z-axis (I'm referring to the bone's "head" location here). To place RIGHT_PEC where SL will automatically place it, select just the head of the mChest bone and "move cursor to selection". Our 3d cursor location in the properties pane (press "n" to toggle) should now be the same as the head of mChest. Now, add the sbx_location_x, sbx_location_y, and sbx_location_z values to the 3d cursor's x, y, and z locations. Select the RIGHT_PEC bone, then "snap selection to cursor". Repeat for LEFT_PEC and BUTT.

7. You will need to upload the rig and mesh separately.

8. Delete any key frames.

9. Be sure to apply location, rotation, and scale to the armature and your un-parented mesh.

10. Edit the armature, select the three cBones and move them to a different bone layer. Be sure that ALL bones are set to "deform".

11. Add an object to your scene. It can be a single triangle. I use a square placed where it will never be seen under the avatar mesh.

12. With only the bone layer with the mBones active, parent the new object to the armature. Just let it generate weights.

IMPORTANT: Verify that the object's vertex groups only list mBones. Even empty cBone groups will mess up your uploaded rig. [note: be sure that your rig is in "rest position" and not "pose position"]

13. Export as SL-OpenSim Rigged.

14. Upload using vertex weights and joint positions.

15. Activate both bone layers so that the three cBones are now visible too.

16. Assuming you already have a weighted mesh, parent it to the armature with empty groups.

17. Export as SL-OpenSim Rigged.

18. Upload using vertex weights only.

 

Attach them, and all should work...