Vellum Cloth and Grain Interaction

[existenceproof]

Hello all, 

 

 I'm attempting to combine vellum cloth and grains on the sop level but a few things look strange. When I merge them before the solver (like I've done in the past with multiple pieces of cloth) it looks like the grains add little square boxes onto the cloth mesh. I'm guessing these are the grain constraints but I'm not sure. Also, when I run the sim the grains stay above the cloth, never actually colliding with it. I assume the two things are related but I haven't been able to sort it out. Does anyone have any ideas? Thanks in advance.

 

 

Vellum_ClothandGrain_01.hiplc

[anim]

those squares are just sprite visualisation of points, which exist on grains as point attribs and also detail to show all points, so after merging with cloth all points will be additionally visualized as sprites, which without a texture is just a square

 

the collision is unrelated to the visualization, your grains are simply too light to affect the cloth in any meaningful way, also their radius may be too small but that can also be your intention

[existenceproof]

3 minutes ago, anim said:

those squares are just sprite visualisation of points, which exist on grains as point attribs and also detail to show all points, so after merging with cloth all points will be additionally visualized as sprites, which without a texture is just a square

 

the collision is unrelated to the visualization, your grains are simply too light to affect the cloth in any meaningful way, also their radius may be too small but that can also be your intention

Hey Tomas, thank you for your quick reply! So if I want sand that is that granular, how would I get it to collide with the cloth? Is my best bet to give the cloth thickness in post or is there a better way?

[Noobini]

if you use vellumpack after the cloth and another vellumpack after the grain, merge these 2, then vellum unpack and feed that to the vellumsolver, you don't get the funny squares.

and....comparing the size of one tri from your cloth with one grain.....the grain is miniscule...there's no possible way a tri would be dented by one of those grains...coz the tri is ginormous, there's not enough geo for it to be bent.

[anim]

it collides, but

- if you are concerned about the gap, it will keep the gap that equals to grain pscale + cloth pscale so then when grain is rendered as spheres and clot has thickness they should touch (also your cloth is already pretty thickfor the sim, I'd decrease it's thickness for the sim)

- if it's about how muc it deforms the cloth, to make collision deform cloth more you'll need to make grains heavier, increase mass

 

[existenceproof]

Thank you both!