Hi,
i have a fbx from maya with a fk skeleton structure, where also inbetween twist joints are present (legs + arms) for deformation.
when setting up the "new" APEX autorigbuilder and want to use the leg (or arm), it always highlights the first 3 joints in the leg joint hierarchy (and not the first, middle and last)...
in the "build" tab i can remap to the right joints, but then the final rig is not constructed right, the controlls are way off and the deformation is destroyed, the leg gets stretched...
i also tried from scratch with a houdini skeleton (with fk twist joints, and with 3 point joints) and it also not working...
does somebody know how to deal with that kind of pre-existing fk twist joints from other DCCs and autorigbuilder?
also is there some info what kind of remap names (from->to) the autorigbuilder uses?
H21.0.440
H21 AutoRigBuilder Issues
424 3 1-
- soulcage_dpt
- Member
- 60 posts
- Joined: July 2015
- Offline
-
- esttri
- Staff
- 124 posts
- Joined: May 2021
- Offline
could you share your input skeleton? that will make it easier to see whats going wrong. You might want to also check out the new production build since we made a lot of bug fixes since the initial release.
I do have one initial suspicion though. The autorig builder expects a default skeleton scale of 1.0 it can very well be that you fbx import added a scale factor of 0.01 to your skeleton. you can get rid of that with a small vex snippet
before packing your character.
Another that is expected for twist is that they are not in a chain with the arm joints. this is actually important!
here are 2 legit options to parent your pre existing twists
upperarm
--> upper_twist_01
--> upper_twist_02
--> upper_twist_03
--> lowerarm
--> lower_twist_01
--|--> lower_twist_02
--|--> lower_twist_03
--|--> hand
upperarm
--> upper_twist_01
--|--> upper_twist_02
--|--|-->upper_twist_03
--> lowerarm
--|--> lower_twist_01
--|--|--> lower_twist_02
--|--|--|--> lower_twist_03
--|--> hand
I do have one initial suspicion though. The autorig builder expects a default skeleton scale of 1.0 it can very well be that you fbx import added a scale factor of 0.01 to your skeleton. you can get rid of that with a small vex snippet
3@transform = polardecomp(3@transform);
before packing your character.
Another that is expected for twist is that they are not in a chain with the arm joints. this is actually important!
here are 2 legit options to parent your pre existing twists
upperarm
--> upper_twist_01
--> upper_twist_02
--> upper_twist_03
--> lowerarm
--> lower_twist_01
--|--> lower_twist_02
--|--> lower_twist_03
--|--> hand
upperarm
--> upper_twist_01
--|--> upper_twist_02
--|--|-->upper_twist_03
--> lowerarm
--|--> lower_twist_01
--|--|--> lower_twist_02
--|--|--|--> lower_twist_03
--|--> hand
Edited by esttri - Oct. 27, 2025 17:17:32
-
- soulcage_dpt
- Member
- 60 posts
- Joined: July 2015
- Offline
thx for the fast reply.
indeed, the maya skeleton (mgear joint skeletons) is in maya units and scaled down with the "convert units" from the fbxcharacterimport.
also the twist joints are in a continous fk chain (joint01->joint02->joint03->etc).
i updated to 21.0.512 and try out your suggestions to see if it solves the issues.
with this update, a 3-point-joint-skeleton seems to work now with the autobuildrig (also i switched to opengl viewport, and it also seems to update correctly. before there where viewport-update glitches...)
indeed, the maya skeleton (mgear joint skeletons) is in maya units and scaled down with the "convert units" from the fbxcharacterimport.
also the twist joints are in a continous fk chain (joint01->joint02->joint03->etc).
i updated to 21.0.512 and try out your suggestions to see if it solves the issues.
with this update, a 3-point-joint-skeleton seems to work now with the autobuildrig (also i switched to opengl viewport, and it also seems to update correctly. before there where viewport-update glitches...)
Edited by soulcage_dpt - Oct. 28, 2025 04:52:20
-
- soulcage_dpt
- Member
- 60 posts
- Joined: July 2015
- Offline
i reparented the twist joints as you suggested and it works now...
the arm and legs are created right.
but i dont know how to map the existing skeleton twist joints to the autorigbuilder-twists...
creating additional mappings i.e. "upper_twist_01" to "my_custom_twist_01" does nothing and rotating the hand controller also does not perform a twist on the created nulls from the autorigbuilder...
any suggestions?
the arm and legs are created right.
but i dont know how to map the existing skeleton twist joints to the autorigbuilder-twists...
creating additional mappings i.e. "upper_twist_01" to "my_custom_twist_01" does nothing and rotating the hand controller also does not perform a twist on the created nulls from the autorigbuilder...
any suggestions?
Edited by soulcage_dpt - Oct. 28, 2025 08:53:51
-
- Quick Links

