5 replies to this topic

[oasfc]

Hi. I am trying to create a simple RBD sim of popcorn falling out of a pop corn box. I have been tweaking the settings of the DOP set up for a while now but i am unable to stop the pop corn from popping around and being very jumpy when in the box. I am currently using ray intersect for my collisions with a value of 100 but even with such a high value the pop corns are not interacting with each other properly. I have tried numerous settings, cranking the solver settings up very high but im still having no luck. I have attached a scene for reference. Any help would be great.

[Mikal]

Don't think you attached the scene file?

[oasfc]

Mikal, on 29 July 2012 - 10:03 PM, said:

Don't think you attached the scene file?

Thanks for pointing this out, i must have forgotten.

Attached Files

•  ref.hipnc   800.66K   12 downloads

[Mikal]

oasfc, on 30 July 2012 - 01:15 AM, said:

Thanks for pointing this out, i must have forgotten.

So. a few things I changed...

For roughly spherical objects like that you might as well use an implicit sphere as the collision object - it'll be quicker and depending how close you are to the object it's unlikely you'll notice the penetration.

I think the popping comes largely from including 'resolve penetration' in the solver - it's not normally turned on by default - basically when the solver finds two penetrating objects it will physically move one or both on that frame to resolve the intersection, and you end up with that popping.

You can reduce the impact the objects are having within the group by reducing 'shock propogation'... otherwise collisions can reverberate around the box and they'll take longer to settle.

Finally increase substeps, it's slower but you'll get a smoother result.

Hope that helps

[Mikal]

Here's the file

Attached Files

•  ref_RBD_01.hipnc   931.67K   10 downloads

[oasfc]

thank you for the help. much appreciated!