Cloth Tearing - Prevent Small Bits?
#1
Any advice on how to prevent too many small, isolated polygons (confetti) during cloth tearing other than using a weakness map?
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#2
Simplest thing to try is to increase the spinner which controls how many frames a bind much be stretched before it's allowed to tear. Usually the tiny fractures happen because the bind is not given enough time to relax after adjacent binds tear, causing lots of tiny pieces to develop.

You could also just put a tySelect on your cloth and select by element size and delete with a Delete Mesh modifier too.
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#3
(03-19-2021, 03:09 PM)tyFlow Wrote: Simplest thing to try is to increase the spinner which controls how many frames a bind much be stretched before it's allowed to tear. Usually the tiny fractures happen because the bind is not given enough time to relax after adjacent binds tear, causing lots of tiny pieces to develop.

You could also just put a tySelect on your cloth and select by element size and delete with a Delete Mesh modifier too.

Thanks Tyson.  These are both things I'm already trying.  The minimums frames helps but also seems to prevent the actual larger tears I want from happening.  Perhaps lowering the tear thresholds in concert will help find a balance.

Deleting by minimum element size does get rid of the smallest bits, but also kills motion blur due to changing topo.
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#4
tyFlow internally stores vert velocity data in map channel 20...technically putting a modifier on top of the mesh doesn't destroy the data...but it does prevent the renderer from being passed that data properly (because tyFlow itself has to do it, but when there's a modifier on top the direct access to tyFlow data is broken).

So try this (to retain moblur):

Put your selection/deletion modifiers on top of your tyFlow and then create a second tyFlow with only an Export Particles operator. Add the first tyFlow to the Export Particles operator additional geometry rollout, then export to tyCache and render as instances....and see if the moblur comes through that way. I believe it should.

I haven't looked at the code, but it's possible that the only limitation to that method is that the vert velocity data that gets baked in only gets baked in during tyCache export (I can't remember)....so if that setup doesn't work, just do an intermediate tyCache export as well. So try tyFlow->tyCache->add mods on tyCache->re-export cache in a second flow.
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#5
(03-19-2021, 04:01 PM)tyFlow Wrote: tyFlow internally stores vert velocity data in map channel 20...technically putting a modifier on top of the mesh doesn't destroy the data...but it does prevent the renderer from being passed that data properly (because tyFlow itself has to do it, but when there's a modifier on top the direct access to tyFlow data is broken).

So try this (to retain moblur):

Put your selection/deletion modifiers on top of your tyFlow and then create a second tyFlow with only an Export Particles operator. Add the first tyFlow to the Export Particles operator additional geometry rollout, then export to tyCache and render as instances....and see if the moblur comes through that way. I believe it should.

I haven't looked at the code, but it's possible that the only limitation to that method is that the vert velocity data that gets baked in only gets baked in during tyCache export (I can't remember)....so if that setup doesn't work, just do an intermediate tyCache export as well. So try tyFlow->tyCache->add mods on tyCache->re-export cache in a second flow.

I will try this.  Thanks Tyson!
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