Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Feature request: internal overlap #44

Open
yuvaltassa opened this issue May 5, 2024 · 2 comments
Open

Feature request: internal overlap #44

yuvaltassa opened this issue May 5, 2024 · 2 comments

Comments

@yuvaltassa
Copy link

Hi CoACD,

I'd like to describe two common issues that we encounter with collisions between adjacent sub-meshes, and propose two related feature that will address one or both of them. I don't think either of the issues is in any way MuJoCo-specific.

Issues:

  1. Penetration of thin objects between two adjacent sub-meshes: When a thin object penetrates between two adjacent meshes, the contact forces push sideways rather than out, leading to jamming of the thin object between the sub-meshes.
  2. Catching on corners: When a pointy (not necessarily thin) object slides along the side of a decomposed mesh, the corner can catch on the corner of one of the decomposed meshes.

Proposed solutions:

  1. "Inflate" all sub-meshes in the direction normal to internal mesh-adjacent surfaces by an overlap parameter $d$, with units of length.
  2. Make the added (inflated) part smooth, by adding several faces that attempt to approximate a smooth bevel at the corners. This requires specifying the smoothing radius $r$ and possibly also the number of added vertices/faces that participate in the smooth corner.

I'm attaching an image below with a sketch of what we are imagining. Note that for us issue 1 is much more significant than issue 2, and the proposed solution 3 is both easier to implement and does not introduce new faces/vertices. However note that solution 4 is more general, since it solves both issues 1 and 2 (but cannot be said to be strictly better, due to the increase in the number of faces).

We'd love to hear your opinion on these proposed features.

IMG_5527

cc @quagla, @btaba, @erez-tom.

SarahWeiii added a commit that referenced this issue Jul 20, 2024
@SarahWeiii
Copy link
Owner

Hi the overlap extrude is added. You can enable it by adding -ex flag, and designate the margin by -em. Now I haven't added the smoothing radius. Hope the current solution works.

@yuvaltassa
Copy link
Author

AMAZING!

We will test and give feedback ASAP

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants