Rendering VDBs

[Ashraf Ghoniem]

Hey Guys,

I have a pretty simple question. I am attempting to render an open vdb in mantra and I am noticing a lot of stepping where if I render a houdini volume primitive I do not see the stepping is there something I am missing?

it's as simple as running isoffset on a sphere than rendering once than rendering a converted version into an open vdb primitive.

[Jeff Budsberg]

hey Ashraf,

I dont have houdini in front of me, but instead of poly mesh->iso offset-> openvdb convert to get your density vdb, can you try poly mesh-> openvdb from polygons?  I wonder if you're losing fidelity in the convert... not to mention from polygons is crazy fast.

-Jeff

[Ashraf Ghoniem]

Hey Jeff,

Yeah I tried that we lose less but still see some stepping. The question is for pyro sims which come out of dops as houdini volumes and we want to go to vdb for storage on disk but with the stepping it makes rendering the vdbs difficult. 

[Ashraf Ghoniem]

also the crazy thing is if you convert back it loses the stepping! pretty weird..

[Jeff Budsberg]

hey Ashraf,
I'm don't see any obvious weirdness on my end..

left to right in my render:
* polygonal mesh -> iso offset
* polygonal mesh -> openvdb from polygons
* polygonal mesh -> openvdb from polygons -> openvdb convert (to houdini volume)

when I get a chance, I'll try a pyro sim..