Jump to content

RBD Spheres fall through box


Recommended Posts

Hey people of the internet,


I feel like I'm being really dumb and I cant work this out. I haven't had much experience with RBD solvers because I usually use C4D for these sort of simple setups. 

Basically I have a load of spheres inside a box and I want the box to contain them. Unfortunately, the spheres just pass through. 

I have fiddled with it and can get it to work. If it's set to bullet it sticks some of the spheres and the rest pass through. 

I have attached a screenshot of my set up.

Screenshot 2020-01-08 at 12.54.42.png

Screenshot 2020-01-08 at 12.54.29.png

Screenshot 2020-01-08 at 12.54.04.png

Link to comment
Share on other sites

Hello Andrew,

to have your box contain the spheres I'd recommend to use a proxy volume inside your static object.

While this tutorial might be for Pyro, the same should apply to RBD and FLIP aswell.

EDIT: If you are using Bullet this approach won't work. In that case you can use a Facet SOP with "Unique Points" turned on and a PolyExtrude SOP after that, in your static object you then tick "Create Convex Hull per Set of Connected Primitives".

Edited by dleonhardt
Link to comment
Share on other sites

Hey Andrew,

I took a quick look at your file. Because you are using Bullet, you need to approach concave collision shapes differently by splitting into multiple convex shapes. And another thing is that your spheres didn't have any names, so Bullet treats all your spheres as single object. I marked all of the nodes I created in red. 

If you have any other questions, don't hesitate to ask.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...