Hi everyone,

I’m currently working on a retarget setup where my target skeleton has very long feet compared to the source.
With a very basic fbik setup (for example with two configurators groups one on hips and one on ankles), as soon as I test anything that involves a foot roll (e.g. a walk), the target skeleton’s feet obviously clip with the floor.

I worked on some solutions but I feel my Houdini inexperience has forced me to come up with some unnecessary complicated setups.


So far, the things I’ve considered are:
-Adapt to terrain: it works well on the ankle but I’m not sure it woks on the toe as well if the plane doesn’t have rotation (I tried the terrain based foot lift but gives me some result only on inclined planes)

-Rig attribute vop with collide geometry that feeds into a stabilize joint: I isolate the toe joint, make it collide, stabilize joint node to fix the slide but the stabilize joint sometimes is not very smooth if it’s not on the floor.
Ideally on the rig attribute vop I could drive the 1st fbik from the ankles and keep an eye on the toe height: if the toe goes through the floor use the collide geometry and swap to a 2nd pass of fbik driven by the toe.

Maybe use the foot roll node? Can I make it work automatically though?


I think I’m over complicating things. I would like to ask your opinion on what would be your approach to have a nice foot roll without clipping and without sliding. I feel a different perspective will be very useful.

Thanks!

I think you're on the right track. I'd try either a foot roll or if you can get away with something simpler, you could also just add an IK chain post retargeting and limit the control points to the terrain. Then pipe everything through a fullbody IK or adapt to terrain.

Adapt to terrain should work on things other than planes. I've definitely used it on terrain geo. If you post a short motion clip with your scene, I'll try to take a look over the weekend.

made-by-geoff
I think you're on the right track. I'd try either a foot roll or if you can get away with something simpler, you could also just add an IK chain post retargeting and limit the control points to the terrain. Then pipe everything through a fullbody IK or adapt to terrain.

Adapt to terrain should work on things other than planes. I've definitely used it on terrain geo. If you post a short motion clip with your scene, I'll try to take a look over the weekend.

sorry I've been away for few days and just checked your message. I will post shortly a demo scene with few options I tried.

Hi and sorry for the late update.

Attached you can find the test scene and the source files.

My approach is the following:

1. map the characters
   
2. isolate the test leg hiearchy
   
3. extract the leg-knee-toe joints to make the iksolver controls
   
4. use collide geometry on the toe
   
5. then make a second rig vop with an ik solve with the three controls over the leg hierarchy using the "compute from targets" option
   

For some reason the leg is flipped and can't make it work. I even moved the knee further to make a more stable pole vector.
Any idea of what schoolboy error I'm making at this stage?

thanks