Collisions in Vellum

[luka_schulz 4]

I want to  change the texture color of colliding objects in vellum. I have been trying to figure out if there is a way to access the collision data from the vellum solver but I can't find anything in the documentation. In the geometry spreadsheet it shows a column for 'hitnum' but the values are all 0 even when my geometry touches. Any tips would be greatly appreciated.

 

Cheers

inflate-test.hipnc

[Midasssilver 13]

Bump

[Midasssilver 13]

I tried setting up a vellum sim inside of dops, hoping I could use a popcollisiondetect to try and get the hit attributes I needed, but that didn't seem to make a difference. Since Vellum is grain based, I thought pop operations worked on them, but I guess not all of them do. Interested in the workaround for this if anyone knows.

[Andrea 110]

Hello! It's possible to detect the collision of the geometry in Vellum. What is missing is that it should be enabled also inside the vellum solver and by default it's not (probably for save memory). If you enable this, it should work as always.

Look at the example file. I have opened the vellum solver and modified the popsolver. I have enabled "Integrate Position" under "Update" and then enabled the collision detection on the "collision behavior" tab.

 

Vellum_collision_detection.hip

 

P.s: for do this is better to create a new dopnet and create the vellum solver here instead of using the solver HDA

[luka_schulz 4]

Thanks Andrea, that did the trick. The two things I am having trouble with now are:

1) Vellum object collision is not registering. I thought it might have to do with the thickness of the cloth (since there is some space between the objects) but changing it didn't affect collisions. I also tried tweaking the the "Search Scale" in the "Advanced" tab of the Vellum Solver, but that didn't do too much either. I feel like I am missing something simple?

2) The collisions look "flickery" when I visualize them. To get around it I have increased the Substep Iterations on the vellum solver which helped a little but it's still a little jittery. Do I need to just increase the substeps or is there a work around for this?

Lastly, I noticed you had increased the "Max Acceleration" on the Vellum Solver and I thought that might help me with my balloons inflating smoothly but they still are pretty jerky when they inflate? Any tips.

 

Thanks again!!

inflate-test-002.hipnc

[Andr1 3]

This came handy thanks!

But for some reason the hitnum attrib never update, and remains at 0.
Do you know why?