Hi,
Im having problems with the tissue solver in H16.5
First my computer crash if I use the default settings for the solid embedding section of the bones and the tissue.
Im using maxTet .1 minTri .005 and disabling the base size, that creates a decent tetra object.


Now the animation stays static all the time and not following the animation from the skinned mesh

Is there a tutorial?
thanks in advance,
-Alex

Tutorials will be ready early in the new year.

The incoming skin must always be static. The tetrahedralized solid version of your skin (the tissue) will be driven by any animated bones and muscles inside. If you look at the sop that is being referenced in the merge_static_skin node, you'll see that it will have skipped over the BoneDeform node in your animation, and instead merged in the static geometry that the BoneDeform operates on. If this input were animated, it would cause the skin to be solidified again and again on every frame. (This would be bad).

The current version of the Tissue Solver does, however, assume that your skin is animated via Bone Capture weighting & Bone Deform. If the capture weight attributes exist on your incoming (static) skin, the solver will detect them and use them. Internally, a BoneDeform operation will be applied to your skin geometry, and this animated position will be used as a Target Constraint on your simulated tissue.

Target constraint parameters can be adjusted on the TissueSolver>Tissue>Skin Animation tab. And, they can be further adjusted by the presence of painted point attributes named “targetstrength” and “targetdamping”.
ie, you can paint a “targetstrength” mask onto your skin, with a value range of 0.0 to 1.0, and then use the Target Strength parameter on the Skin Animation tab to adjust (multiply) it's final strength.

Keep in mind that the target strength is a force, and as such, it will attempt to attract your simulated tissue to the constrained location while factoring in all other physical forces at the same time. So your simulated result may not necessarily match your animated positions exactly.

Future versions of the tissue system will include a more intuitive paint setup, and support for skin animation coming from non-captured workflows.
-j

Thank you John!

It didn't work I think is not catching the bone weighting right
I went inside the tissue system and I found this.
How I can fix it, Im using a FBX.
thanks, Jhon.

can you post a hip file?

Thanks!
https://www.dropbox.com/s/oxj0bpmsgkf914p/bobo.zip?dl=0 [www.dropbox.com]

hi alexis,
sorry I should have noticed the grid markers in your snapshot images, the scale for your character is huge. This is the source of your problem. When dealing with dynamics and the tissue setup, it's not only best practice, but almost essential, that you use real world scales for your objects. By default, houdini's dynamics use 1 unit = 1 meter. And unfortunately, it's not so simple to change the default unit of scale and have everything work correctly in this instance. You ought to consider scaling your character rig and your geometry objects by a factor of ~0.0015 to get in the ballpark. You should then re-capture at this scale to get your bone transforms to affect the skin geometry correctly.

thanks, John!
I knew that huge size will cause me problems

Sorry to bother you again but still not moving even with target strength of 1.
I scale it everything and went inside the tissue solver and now is catching the weights right.
But the tissue is not doing anything.
Thanks in advance
https://www.dropbox.com/s/gjud8tpzehkkwra/bobo.zip?dl=0 [www.dropbox.com]

Is working now, thanks for your help!

Is working now, thanks for your help!

Glad to hear you got it working.

I did manage to take a look anyway, and I think you stumbled across a bug in the way the the input nodes might have been disconnected from the solver, but the “Include” toggles were still instructing the solver to use those items. The solver may have been erroring out and it looked like it wasn't doing anything. I've committed a fix for this and it should be available in the next daily build.

The Target Strength parameter had to get up in the neighborhood of 30,000 in order for the tissue to not fall away from the animated target position.

When combined with a painted mask for the targetstrength, ie:


The solver produced this:



Without any internal bones or muscles, the tissue is only constrained where the mask is non-zero.

By adding some very simple bone geometry, it's enough to hold the bulk of the tissue in place:

(sorry about the busted formatting in that last post.)

Hi, I am having the same issue here - the solver is cooking something but its not outputting any animation at all
Scaling should be ok, tried also setting target strength to 30000 but its still not moving.

Are there any tutorials how to make this work?

thanks!
V

Still no any tutorials on this?