Cineversity

I’m attaching the full dress to the character by using the cloth belt tag using all the dress’s points from the waist up. I’ve got the cloth and cloth collider tags set that when I start the animation the lower part of the dress nicely drops and collides with the character legs.

But as soon as I add the dress to the full character project and the character moves, the lower hips and legs tear through the dress. After spending hours deleting different parts of the full project, I found the character’s main morph tag was the problem. Even if I disable the morph tag, put it in edit mode, or set the main strength to zero, the cloth tears.

If I delete all the keyframes for all the morphs, then tearing stops. I don’t even need to zero out the morphs.

I have a sample file that I could seed that is 18 mb, but would rather not post it publicly. Unless anyone knows why the cloth doesn’t like animated morphs.

Hi brucek5,

Please check your Private Message; I have sent you a Dropbox link a while ago.
I will keep it private.

Cheers.

Dr. Sassi,

I got my fairly large project file stripped down to the bare necessities to demonstrate the problem.
1) If you click play, you’ll see the dress tearing off.
2) Then go to the morph tag, shift-click all the morphs, and right click Animation-> Delete Track. No need to zero-out sliders.
3) Click play and now you’ll see the dress no longer tears.

Unrelated, but for your FYI, I also sent you a picture of this character rendered using Redshift. I spent a lot of time making all the shader maps and getting the SSS material to look close to human skin. All the face morphs are set using my Python script that converts the Face-Cap FBX file as well as making random facially movements to give it a more “alive” look when animating.

Hi brucek5,

Thanks for the file.

My first test was to run the Point Cache on the character. Then disabling Skin and Pose Morph. The push through the dress is gone. The idea was to get the data from the animation to be unified. It seems that the keyframes are not placed in the middle of the frame. Since I have never had a question here that put the Pose Morph as the problem, I wondered if the Point Cache would do the trick here. I think it did.

The second part was, of course, to explore the settings of the dress, which was set to be pretty stiff, and Friction of 100% is certainly not what a dress can produce.

Please have a look at the screenshot for the values that worked with the example. Next, I would apply the Cloth object to add some thickness, covering up the tiny push-throughs. If possible, place an alpha to all polygons hidden by the dress as an alternative.

I hope that helps.

All the best

Hi Dr. Sassi,

Again, thanks for the amazing quick support (tell who you report to for me)!

I’m lost on your first paragraph:
1) What is a “Point Cache” on a character? Is this a special tag or a process I run somewhere?
2) On disabling the skin and morphs, how wound this impact other deformers in my real project that include collision deformers and giggle deformers?
3) Is the root problem caused by not having morph keys aligned with frames?

I’m hoping the #3 is the root problem, as I could modify my Python script to figure where the track spline value is at a give frame, then place a key there and remove the keys in between.

I’ll add thickness to the dress, as discussed on an earlier forum post, Redshift SSS shaders and alpha materials don’t work nicely together. I have enough challenges just getting multiple SSS Shaders to transition together. The rendered image I sent you, you can see the transition between the face and the neck.

Bruce

Hi brucek5,

When you wrote that you used Python to run your character, I might have assumed you know all the parts of the Character toolset. Sorry, my fault.

1) What is a “Point Cache” on a character? Is this a special tag or a process I run somewhere?
Object Manger> Tags> Rigging Tags> Point Cache.
Anything that moves points (Deformers, Skin-deformer, PoseMorph, etc.) can be cached with this tag.

2) On disabling the skin and morphs, how wound this impact other deformers in my real project that include collision deformers and giggle deformers?
Once it is cached, the initial influence to the points needs to be shut off; otherwise, the point cache and the initial influences will double the change of the point’s position.

3) Is the root problem caused by not having morph keys aligned with frames?
I have no idea. It felt like that the processing of changes were not really clear, and the Point Cache indeed summarizes all movements.  Anyway, I’m not certain here. I have not looked deeper into it, as the Cloth settings were way off, from my understanding of what cloth/fabric would need. If the Cloth is too stiff, then it fights the collider, of course much more. This might be possible to counteract with an enormous increase of sampling, but that will work after a while only if you cache or your scene moves very slowly.

There is even a Cloth Cache tool, Main Menu>Simulate.

As a side note, it was sometimes beneficial to add simple geometry as a collider in other cases with Cloth problems. Like the upper legs of your character could have a simple (extra/invisible) geometry that follows only the upper leg Joints while being slightly larger. With this, these colliders have no idea about a Pose-Morph at all.

Cheers

Hi Dr. Sassi,

So I tried a test where I deleted all animation, including all morph keys, everything, from the project, and zeroed all morph values. I changed all the cloth settings to your suggestions (expect sub-sampling which it kept at a value of 3). I didn’t add cloth thickness so I could see what triggers the tear. I ran the animation and no cloth tear.

Then I set only one morph value to 50% at frame 0 and set a key. Still no cloth tear.

Then I set the same morph (and only one) to a value of 50.001% at frame 40. Now the cloth now tears.

Then I set the same morph (and only one) to a value of 100% at frame 40. The cloth tears exactly the same as the morph change of .001%.

Then I made the dress have thickness of 1 cm (pretty big). The “thick” cloth tears exactly the same.

Then I set the cloth sub-sampling to the suggested value of 36. The cloth still tears, just not as much.

These tests, to me, rule out keys not being on a frame, and cloth thickness. In addition, even if I have the character move 30 cm in 14 frames, then spin around 180 degrees in only 14 additional frames (which is unrealistically fast) with cloth sub-samples at a value of 3, the cloth still doesn’t tear (and looked pretty cool), so that rules out the sub-samples are the root issue, My conclusion, is the cloth tag doesn’t like morph animation no matter how small or slow. Only using the Point Cache produces the same results as no morph keys, even with sub-sample still at 3.

I can use the Point Cache to move on, but it seems like there either something about my project file or a bug in Cinema 4D R21.207 (that I know can’t be fixed). Having to re-run the cache anytime I edit the animation will kind of suck.  It would be interesting to see if the latest version of Cinema 4D does the same.

I think we can call this forum posting as closed.  Thanks for the help.

Bruce

Thanks for the test, brucek5.