Hi,

I'm running a simulation of a few thousand RBDs (small shards – exploding windshield), and I realized that at the end of the sim almost half of my RBDs are “gone”. Upon further examination it turned out that the geometry point coordinates of the disappearing pieces became NaNs – this coming from the DOP network where these pieces' sim attributes became NaNs as well.

(The event that triggers this seems to be a collision, as on the same frame it becomes NaN-ned, an Impacts data also appears on the object)

I'm currently experimenting with various solver settings and whatnot that perhaps would get rid of this problem.

Anyone seen such a thing before?

cheers,
imre

Bumping this thread from spacetime but no one has really answered this on the forums.

Is there any ways to debug NaNs?

I'm in a somewhat similar situation, i'm pretty sure my collision objects which are growing and changing shapes are affecting the sim and blowing up forces (division by 0?), but I can't find a way to debug the scene(s).

If you are using POP Drag, POP Wind POP, Drag Spin or simply @targetv + @airresist your bullet sim is likely to be unstable and result in NaN's
So until that's fixed I'd suggest replacing them with wrangles that dampen v@v and v@w directly

Hey

I just had the same issue and wanted to add, that in my case it was caused by particles getting a pscale of 0.
Changing this to a very small number instead of 0 fixed the issue.