Hey guys,

I have some mocap data that has been supplied to me from our university mocap facility, I've been given the data as both .BVH (which I converted to .cmd and .bclip) and .fbx, both seem to import fine into Houdini.

The problem arises when I try to apply this mocap data to a Biped Autorig that I've setup. When i try to follow the instructions in the help file I get an error message in the terminal when I try to click ‘Generate Mocap Rig’ in the Biped Animation Rig node.

The error is:


Error running callback:
list index out of range
Traceback (most recent call last):
File “<stdin>”, line 1, in <module>
File “opdefObject/Biped_animation_rig?PythonModule”, line 8, in createMocap
File “autorig/mocaprigutils.py”, line 23, in new_func
File “autorig/mocaprigutils.py”, line 1124, in createMocap
File “autorig/mocaprigutils.py”, line 719, in createMocapRig
File “autorig/mocaprigutils.py”, line 321, in createRootNull
IndexError: list index out of range


The mocap skeleton is copied into the new Biped Mocap Rig node, but nothing else seems to happen. I think there are meant to be options for connecting the Biped Animation Rig to the Mocap skeleton, but I can't seem to find them.

So I tried to manually connect the animation bones to the mocap skeleton, but I can't seem to figure this out either. It's been quite a frustrating day trying to get these things to play nicely together!

So I've attached the file I'm working on, I've very quickly (and badly) painted the capture rig onto the mesh so in theory it should deform once the animation rig is linked to the mocap data.

It would be a great help if anyone could have a look and perhaps see where I'm going wrong with this? If it helps I'm running this on Linux, and have tried with releases 10.430 and 10.528.

Cheers,
Gary

The problem seems to be the result of the type of nodes in the skeleton network. For the mocap skeleton, Houdini expects that it is built out of bones with a Null as the root. It then performs modification on these bones and null to make it compatible with the Autorig. The skeleton here is built out of all Geometry objects so Houdini doesn't have a clue what to do. Did you convert the data with mcbiovision with the w flag?

Connecting the parts manually would be a pain in the ass and you'd have to make use of the actual corresponding mocap_rig_biped_* pieces. Houdini needs to use them to calculate transforms and such. Even doing that though it would be quite complex by hand and isn't recommended.

Hi Graham, thanks for the quick reply.

Yeah, I had followed an online tutorial on converting biovision files and it said to use the -w flag, I have reconverted a BVH file without the flag and it imports as bones correctly.

Following the instructions again I can now generate the Biped Mocap Rig and Mocap Dialog Nodes, but I have run into another problem when I try to assign the bones to the various parameters in the Mocap Dialog Node.

I have selected the various nodes, and when I hit ‘accept’ I get an error message in the terminal:


Error running callback:
'NoneType' object has no attribute ‘name’
Traceback (most recent call last):
File “<stdin>”, line 1, in <module>
File “opdefObject/mocap_dialog_node?PythonModule”, line 43, in accept
AttributeError: ‘NoneType’ object has no attribute ‘name’


The issue is that it doesn't seem to bind any of the animation rig bones to the mocap rig.

I have tried this same workflow with the toon character autorig and a different mocap file and it seemed to work fine, but I can't seem to get it working with the Biped Autorig.

I have attached another scene file with the current state of the file, I'd really appreciate it if you could have another look to see if there's anything else wrong with my setup.

Cheers,
Gary

I've made a slight bit of progress with the file, trying to manually assign the autorig bones to the mocap data in the Biped Mocap Rig.

By assigning the parameters and playing with the bone lengths I get an approximate version of the mocap data (I've attached the scene file, I've only modified the Left Arm at this point but if this method works I wouldn't mind doing the rest of the bones manually).

Now the issue is that I can't seem to get the Biped Animation Rig to link to this Biped Mocap Rig, so the Deform Rig isn't moving.

Sorry to be such a pain with this, but I've been working on the file for hours now and seem to keep hitting brick walls!

Thanks again,
Gary

Looking at the dialog node, all the paths in there are weird since they point to the mocap rig then up a level to the deform rig. This is what's causing your errors. The .bclip file is also missing.

Could you please post a version of the file with the imported skeleton and the auto/anim/deform rigs before you try and create the mocap rig, as well as the corresponding .bclip file?

Apologies Graham, I thought that I had embedded the bclip data into the hip file, but I must have turned off the node lock.

I've attached a zip file with the scene before generating the autorig, and the bvh, cmd and bclip files.

Thanks again for your help, I really do appreciate it.

Gary