hello everyone, i have been fiddling with Houdini a lot and progress is actually going great but i'm stuck on one issue i have tried to not only fix myself but i looked online to find no help on it.

The issue is that when i make 2 rbd objects(ex. wall and ball) to collide in fracturing destruction glory i get this invisible space between them that is acting as a collision surface for either my ball or wall(or both), here is a pic of what i mean.

Hard to say without visualizing your boundary objects. In Houdini the viewport object is not the actual object that collisions are calculated against. An invisible boundary object is often created, behind the scene, to act as a collider.

If you are using Volume based collision you can turn on the visibility of the collision object. When the volume resolution is too low, the boundary objects often look like lumps and do not collide very accurately.

Enivob
Hard to say without visualizing your boundary objects. In Houdini the viewport object is not the actual object that collisions are calculated against. An invisible boundary object is often created, behind the scene, to act as a collider.

If you are using Volume based collision you can turn on the visibility of the collision object. When the volume resolution is too low, the boundary objects often look like lumps and do not collide very accurately.

ah volume based collision, just googled that and I got the results I'm looking for i will be looking into this to fix my problem now but if i still have issues i will come back, thanks a lot bro.

This is most likely due to a fast moving collider and the actual collision happening between frames.

To check you can turn off integer frame scrubbing and scrub between the two frames to see if indeed the collision is happening between frames.

Do you get a proper fracture result as the simulation progresses?

jeff
This is most likely due to a fast moving collider and the actual collision happening between frames.

To check you can turn off integer frame scrubbing and scrub between the two frames to see if indeed the collision is happening between frames.

Do you get a proper fracture result as the simulation progresses?

yes i do get a very accurate simulation after the collision and i will try that out right now and get back to you


EDIT: Just tried it and it isn't the issue because at frame 9.017 when is the collision happens and they aren't making contact at all.

Have a look at your collision padding on your rbdobject or rbdpackedobject node inside the DOPnet - this is by default set to 0.02, not to 0.

If you are working on a very small scale, this could cause gaps that look relatively large to your geometry.
Try setting the padding to 0, or scale up the geometry you are working with.

You can find Collision Padding in the Bullet Data tab (rbdpackedobject node).
On an rbdobject node it will be Collision/Bullet Data.

Also, in the case of rbdobject, in your RBD Solver/Volume tab you will find a parameter called Uniform Divisions. This is set to 30 by default.
Turn on Collision Guide to see what it is doing, and see if the collision geometry it creates is different from your actual geometry. If so, you may want to scale up that value.