Bring RBD objects to complete stand still

[Nicholas Yiallouris]

I'm doing some ground interaction debris and I've set up the system to drop the debris on the floor but the debris never comes to a complete stand still.

 

I've tried:

increasing the friction to ridiculous amount

increasing the substeps

changing solvers (Bullet - RBD)

added a drag (which did the opposite)

changed split impulse

used concave

 

Any other suggestions?

 

 

 

 

[jmpr]

Hi 

Try the rbdautofreeze DOP, it will freeze any simulation object under a specified threshold (velocity)

 

Cheers

[whodini]

rbdautofreeze should do the trick. But I;ve also found that the collision shape makes a difference too. Sometimes When using bullet, I would set box as the preferred collision shape if I'm simming small debris chunks. The box shape helps them feel "heavy" and stops them from rolling around too much because it's flat on all sides. I wouldnt recommend using this trick on close up geo or if you need very accurate collisions.

[Nicholas Yiallouris]

Thanks.

 

Will give both options a try now

[rayman]

You can also try to add some artificial drag.

Write something like this

v@v *= 0.9;
v@w *= 0.9;

inside geometry wrangle dop .

 

You can also chek for velocities magnitute and use this expression only if certain threshold is exceeded, so the simulation wont look less "alive".

[Nicholas Yiallouris]

ah see. Thanks.

 

All these suggestions work well on 99% of my DOP objects but there's always one rogue piece that does some funky stuff.

 

Is there a way to delete a specific DOP object?

[pezetko]

Delete DOP if it's object, POP Kill DOP if its packed or point (particle).

[Netvudu]

Also remember that, unless you use packed objects,you can call specific DOP objects as a group, so it should be simple to "tame" a single piece.

[Allegro]

Wait... so RBD Auto Freeze works for you guys with Bullet?

I can very easily get it to work with RBD objects, but I *cannot* absolutely *cannot* get it to work with Bullet in either the latest daily or latest production builds...

[Allegro]

I take that back. It works if you don't use packed objects.

Packed fractured object does not work with rbd auto freeze. Non-packed fractured object does work with rbd auto freeze.

[jonp]

For a packed object you could do this in a POP Wrangle:

float freeze_limit = 0.5;
if (length(@v) < freeze_limit)
    i@active = 0;

[demoan666]

@rayman Hi, this snippet

v@v *= 0.9;
v@w *= 0.9;

used on a popwrangle with animated activation frame pretty much worked, i would appreciate a lot if you could explain how velocities are affecting and what the values represent + would you be so kind to write the snippet where you mention about checking the magnitude of the velocities.