I'm using the new Muscle and Tissue workflow for the first time and as the title suggest I've ran into an issue where my tissue surface isn't colliding with my muscle surfaces. When my creature is lifting it's leg the thigh muscle goes straight through the tissue surface. The result looks like the leg is too soft and collapses into itself.

The motion is not very fast and I get the same result when increasing substeps. Increasing the collision radius on both the muscle and tissue doesn't change the result either.
I get muscle intersections all over the creature, even at parts that barely moves during the pre-roll range, but its most noticeable as the leg moves.


I can't share my project, but I might setup a example scene if I get stuck for too long.

The tissue surface is suppose to collide against the muscle surfaces, right? Any idea what can cause it to just pass through even at very slow speeds?

please post a simplified example if possible.
Or if you're concerned about confidentiality, you could submit a bug on the support page.

I'll try to remember to circle back to this when I'm able to provide a simplified example, I think there might be a bug in the tissueVellumSolver or the documentation could be worded better.

I managed to solve the problem by converting surface of the muscle tets to polygons manually.
From what I gather the tissue solver sets up internal collision surfaces, but the muscle surfaces are not picked up unless I convert them to polygons manually (I did not see this mentioned in the documentation).

See the attached image for my fix (green network box). Hopefully this is helpful to others that experience the same issue.

stereocolor
I'll try to remember to circle back to this when I'm able to provide a simplified example, I think there might be a bug in the tissueVellumSolver or the documentation could be worded better.

I managed to solve the problem by converting surface of the muscle tets to polygons manually.
From what I gather the tissue solver sets up internal collision surfaces, but the muscle surfaces are not picked up unless I convert them to polygons manually (I did not see this mentioned in the documentation).

See the attached image for my fix (green network box). Hopefully this is helpful to others that experience the same issue.

Oooh, Thanks you! Have been pulling my hair out over this. Works like a charm

However, I now am stuck at the skinning stage. No matter what I pipe into the input2 the simulation wont move at all.
The Attach geometry moves fine, but the skin just sits there motionless.

Hard to say from just a snapshot of the nodes. Do you have a valid t-pose attrib on your Attach geometry? You can also try blasting all but a small subsection of the skin (like a small rectangular patch), and feed that into the first input of the solver. Then on the Visualize tab, display the Attachment Vectors. There should be visible attachments constraining the piece of skin to the 2nd input geometry.