Imported fbx skel and mesh from Maya.. but need to replace it and keep my muscle setup?

[anthonymcgrath 67]

Hey all ok I have a simple joint chain anim done in Maya..  4 bones and a tube animating to bend the tube.

I've imported it as fbx (merged into scene).. it all comes in as a subnet package with joints and skinned mesh.  All looks good.

 

So I've been testing the muscle sim and basically I'm connecting the muscle start and end points to joints in the subnet.  Right now it seems to work fine.. joints animate.. muscles follow.

 

However I now need to update the anim on the 4 joint system.  This is easy enough Maya side.. animate.. export fbx.. job done.

 

BUT.. now I want to replace the existing bones/skel animation data with the one from my new fbx. And I've no idea how to do that.

Can anyone help here please?  Id be a bit miffed if I need to keep reparenting all those muscle nodes each time an anim changes lol.

 

Ta!

Ant

[anthonymcgrath 67]

Anyone able to suggest anything for This?

I'm wondering if i need to setup a duplicate of the joint system in bind pose in Houdini..  using hou joints etc.. Then somehow bind or parent constrain those joints to the fbx joints.

Then drive my muscle sim via the hou joints.. but the bonus is I can iterate on the anim in Maya..  export fbx and plug back into Houdini auto updating the hou joint anim and muscle sim?

[anthonymcgrath 67]

Hey guys can anyone offer any advice on this?  It has to be possible surely?  I've been banging my head in this.. if I can't replace an fbx things like like a muscle sim become a total nightmare to keep reconnecting 

[StepbyStepVFX 62]

Hey,

Just an idea : you can import both FBX - the one you have worked on, and the one with the new animation.

Then create a CHOP network, where you import all channels related to your bones - tx, ty,tz, rx,ry rz -  (the initial bones, and the re-animated bones, to have all channels created). From there, I think you can reshuffle the channels from your re-animated bones toward the initial bones... and voila.

The nodes to use should be Fetch CHOP / Geometry CHOP (don't remember), to create the channels, and the Export CHOP to export the channels from re-animated bones toward the channels of initial bones.

Not sure I am helping you, but I think CHOP is the way to go :-)

 

[anthonymcgrath 67]

On 01/10/2018 at 3:05 PM, StepbyStepVFX said:

Hey,

Just an idea : you can import both FBX - the one you have worked on, and the one with the new animation.

Then create a CHOP network, where you import all channels related to your bones - tx, ty,tz, rx,ry rz -  (the initial bones, and the re-animated bones, to have all channels created). From there, I think you can reshuffle the channels from your re-animated bones toward the initial bones... and voila.

The nodes to use should be Fetch CHOP / Geometry CHOP (don't remember), to create the channels, and the Export CHOP to export the channels from re-animated bones toward the channels of initial bones.

Not sure I am helping you, but I think CHOP is the way to go :-)

 

Hi yeah this is pretty cool and makes sense. So basically I would have my target skeleton at base pose and my animated skel..  and I transfer the anim to the target skel.  The target skel will have extra stuff on it e.g. muscle sim perhaps.

 

I've not much clue how to set that up in chops.. I imagine it's ok for one node but getting it to work with 100+ bones could be monotonous.  Is there by documentation or tutorials for such a thing ?

[StepbyStepVFX 62]

5 hours ago, anthonymcgrath said:

I've not much clue how to set that up in chops.. I imagine it's ok for one node but getting it to work with 100+ bones could be monotonous.  Is there by documentation or tutorials for such a thing ?

Depending on your naming convention, you can use a fetch node to select all the rotation channels of your bones at once, using /obj/animated_bone_name_*, and exporting using teh same pattern. You can also fetch translation channels if required.

If the bones are named consistently, the channels should be assigned in the right order. So no tedious assignement between rigs :-)

Check the file attached.

chopTEST.hip

Edited October 3, 2018 by StepbyStepVFX

[StepbyStepVFX 62]

Hope that will help you !