Dynamic cloth under stress

• @F_Verbaas Here is how the mesh flows around the figure. I think it is tight enough (I looked sharp at a real model how cloth wraps around a body :)).

I do not think it is a weight issue. It looks more like there is more shape in the mesh in the area than the figure can fill.
If you assume shape is made by stretch, (in real life fabric this usually means ther are no darts or figure-seams) best start from a fit for a flat-chested figure and let the breasts 'grow in' by morph.

Not "weight" but elasticity. But the size of the polygons in the area are a factor too. The farther apart the vertices have to move apart, the harder it is for the polygons to hold their shape and bend, so poke thrus occur. More polygons equals better elasticity and better bending and stretching.

I take it this is before the simulation? And the fabric that covers the breast sags a little during the simulation?

• @fverbaas Yes, before the sim. If cloth-density is set too light, you can identify the denser area. I think it has something to do with air-damping.

• It is a common phenonenon. Let me try to explain.
The simulation starts without strain in the garment so there is no pressure of the garment on the figure, so also no friction. There is however gravity pulling the garment down. Initially there is no force to counteract gravity, so gravity does its work and the garment begins an acceleration in the downward direction. In the second step, there is a velocity in the negative-y direction. In the third step there is a displacement in the -y direction, so strain may begin to build up, friction builds up, and the two begin a battle against gravity. It takes some time first to build up counter force against gravity and then to reduce velocity until the garment can begin the way back up, that is, if the garment is not caught in the lowest position (max pressure so max friction)!!. In the mean while substantial sag has built up, which will have made the 'cup' in the garment slide down off the breast, leading to a void below the breast point.
The fabric dome spanning the void is likely to collapse under the load, and that is what you see: a mis-aIigned collapsed preform 'cup' in the fabric.
In real life the fitter would lift and 'pluck' the garment a little to make the cup return to its position. Poser clothroom does not have such a 'plucking' possibility.
The solutions? Not one in general that is perfect but a few things that will help:

• Make gravity come in slowly in the sim.

• Use constrained vertices

• Use flat clothing and build breast shape in the course of the sim.

Have fun.

• @fverbaas Thanks.

• This is working well. Following with interest.

• This is working well. Following with interest.

You and me both :)

• I think I have it now. Dynamic trousers under heavy stress:

No constrained or choreographed groups at all!

Because there is nothing constrained, in this pose the waistband is pulled down at the back. Like in real. And note: The waistband keeps it's form!

• There are intersections in the figures. On thigh/shin and tigh/hip/abdomen. The figure is a standard Roxie, no morphs used, just posed.

• Before someone asks: No postwork, no morphbrush used, simple shader without bumpmap or displacement.

• @adp said in Dynamic cloth under stress:

There are intersections in the figures. On thigh/shin and tigh/hip/abdomen. The figure is a standard Roxie, no morphs used, just posed.

Not necessarily. Remember that there is a minimum distance of space between the cloth and the figure and that space is measured in centimeters. The only way to know for sure if there is intersection is to push the camera inside the figure from the other side to see.

• @adp said in Dynamic cloth under stress:

There are intersections in the figures. On thigh/shin and tigh/hip/abdomen. The figure is a standard Roxie, no morphs used, just posed.

Not necessarily. Remember that there is a minimum distance of space between the cloth and the figure and that space is measured in centimeters. The only way to know for sure if there is intersection is to push the camera inside the figure from the other side to see.

You are right. I exported the posed figure to my modeller and explored it there. No intersections at the knees. But the thigh intersects deeply with the hip.

It's the version I used to render the last images. Not optimial because I made some cuts here and there just to try. Means: Has some more Polys as needed...

• @adp said in Dynamic cloth under stress:

@adp said in Dynamic cloth under stress:

There are intersections in the figures. On thigh/shin and tigh/hip/abdomen. The figure is a standard Roxie, no morphs used, just posed.

Not necessarily. Remember that there is a minimum distance of space between the cloth and the figure and that space is measured in centimeters. The only way to know for sure if there is intersection is to push the camera inside the figure from the other side to see.

You are right. I exported the posed figure to my modeller and explored it there. No intersections at the knees. But the thigh intersects deeply with the hip.

Just for the sake of my own curiosity, how was your Cloth Collision set up. The default is Cloth Polygon to Object vertex, I think. But did you enable Cloth polygon to object polygon?

• @eclark1849 can't speak for @adp but I always set all 3 options in the simulation settings. I used to go with the default unless it needed changing, which it nearly always did so now I set them by default. (would have loved to be able to programmatically create the sim, but those options aren't exposed in the Python API :(

• Just for the sake of my own curiosity, how was your Cloth Collision set up. The default is Cloth Polygon to Object vertex, I think. But did you enable Cloth polygon to object polygon?

As @amethystpendant said: All 3. And don't forget to set "collision Offset" low enough (I mostly use 0.2 or 0.15).

• I tried hours with a low-poly model. No chance. Even not if denser on the critical parts. Because to mutch different poly-sizes results in deformation, poke-trough or randomly exploding vertices even on spots not under stress.I assume the reason is that the clothpiece is very tight.