Hi,

I have a problem with moving collision with glued objects.
I have a static object moved by Point Position then the collision works fine.
(I need to move static object by Point Position to get glued object to follow static object position.)
But when I add RBD object to glue to the static object, it doesn't look collision works fine. They kind of still collide but it doesn't look considering velocity of the static object and glued RBD object.

I would appreciate any idea to solve the problem.

Thanks,

Ryoji

Instead of gluing , if you apply similar motion to sticky obj, turn on deforming geo. Add some vel to sticky obj by using rbdstate node. See the attached file for other settings on rbdstate dop.
I have used a fixed number in vely param of rbdstate. Write some expression there which generates positive values when sphere is going up and negative when sphere is going down.
This should give you the expected result.

I think it's something with Split Impulse feature of the bullet solver and glued objects.

You can increase Number of substeps in bullet solver to something like 50+ (better 100+).
Or disable Split impulse
Or put two bullet solvers - one for boxes and one for sticky object. This way you don't have to increase substeps and overall sim looks most believable.

I don't know why it happens though.

sadhu, thanks for your sample scene.

Unfortunately, my actual scene is more complicated. I used RBD fracture for both moving object and glued object because they are multiple objects. But your technique that modifying velocity by RBD state might be a good way. I'll try some more.

thanks,

Ryoji