The collision file generation for YCB objects

[zerchen]

Hi @yzqin,

Thank you for sharing the code for this great work!
I would like to know how to generate the collsion files (in stl format) for YCB objects. I find that sometimes collision files for a certain object (e.g., mug) consist of many parts of its mesh (here). Could you please share some tips or codes about how to decompose the mesh and generate these collsion files?
I notice there is a closed issue #8 related to the YCB format, but I guess it is mainly about how to generate the visual mesh.
Thanks in advance!

Best,
Zerui

[yzqin]

Hi Zerui,

Why there are so many mesh for a certain object: Many simulator, e.g. MuJoCo, requires convex mesh to better handle collision detection. Thus we need to perform convex decomposition before use it in simulator. Some objects, like mug, are highly non-convex. So the convex decomposition may generate many mesh files.

When I am working on the dexmv project, I am using vhacd for convex decomposition.

You can also choose to use coacd to do that. It is a recent work that can provide better performance than the vhacd.

[zerchen]

Hi @yzqin ,

It makes sense! Thanks a lot for your detailed explanations!