My made a ball as 0.005 houdini unit big, then I can't get the SDF through isooffset or in the rbd object (nothing in the collision guide).

Are there any limit of SDF due to the scale ?

I tried creating an sdf for a sphere of 0.005 radius, and it did work in the isooffset node. I have attached a hip file that converts the sphere to an sdf and back to geometry.

As you can see the sdf is there. The way the volumes are displayed, the way you perceive density is very dependent on the scale of the volumes. (I always forget if that is actually correct or not :-) )

Anyway, in the rbd object you should see the collision geometry since it is drawn as a surface, I have not tried that.

Hope this helps.

Cheers,
koen

ps this file was build in Houdini 11

Hi Koen, thanks for the reply.

the sphere does work, but I don't use the sphere sop, but subdivided box instead.

try to make a box -> subdivide -> transform (set scale 0.001) -> isooffset


It doesn't work.

when I scale it up, or change the geo to sphere sop, it works then.

but I do need the subdivided box not the sphere sop.

true, i cant get it to work either.

hope you'll be able to find a workaround that works for you.

Cheers,
Koen