Using custom geometry with rigid body as particles

[jakob-wagner]

Hi

I'm trying to create a specific setup with the particles system in C4D:

1. A particle system creates a bunch of particles with a velocity.
2. The particles shape is one or more different custom objects/geometries. Not spheres.
3. The objects will inherit the velocity of the particle, but then physics simulation takes over.
4. The objects falls and lands and comes to rest. The collision cage is not a sphere, but fits the custom geometry.

I can't find a setup that will simulate correctly. I have tried to create a particle system which is then being used by a cloner, but I get the following problems:

1. The objects penetrate the colliders and the other objects. They suddenly jumps (like popcorn) at random times. Probably because the intersect with the collider geometry.
2. The seem to keep sliding. Perhaps following the original particle a little bit?

I've attached the following files:
test particles.c4d - a test setup of the described attempt.
bunch of eggs.c4d/bunch of spheres.c4d - a test with a lot of eggs or spheres, but no particles.

The "bunch of eggs.c4d" file is to test the collisions. Although I don't think that is the only problem, a lot of my problems have to do with that. In these two simple files I get a lot of penetration between the colliders and the eggs. I don't get the same problem with the file with the spheres.
I have tried to give it a lot more substeps/iteration/passes but no luck. I have also tried to set "Collision Shapes" to a higher value. No change. That brings me to another question; is it possible to see the autogenerated collision cage generated?

Sorry for the long post, any help is greatly appreciated.

test particles.c4d
bunch of spheres.c4d

Thanks,
Jakob

[jakob-wagner]

For some reason I can't upload the bunch of eggs scene, but it was exactly like the bunch of spheres file, but with eggs instead.

[Dr. Sassi]

Hi jakob-wagner,

Thanks for the files!

The eggs grow based on your particle setup and the scale slider inside the MoGraph Cloner.
When they land on the Stage, the growth might be faster than the calculation, and they go through the Stage.

Things look better if you set the Scale slider to zero in the MoGraph Cloner.

However, if that scaling is wanted, here is an alternative that ensures that the eggs reach full size before the "land.

CV4_2025_drs_25_MGeg_01.c4d
I have those "remeshed", and you get the shape back with an SSD.

The Collision shape was set to Auto, Complex Hull should work or Triangle mesh. Check in Attribute Manager> Mode> Scene> Simulation> Simulation (Tab)> Draw, what works best.

I also set the Scene to 20cm, which was on Default (100cm), and increased the Steps.

Enjoy your weekend