How to prevent this volume artifact?

[magneto]

Hi,

I am not sure what it's called but is there a way to prevent it? I sort of thought this is happening because of using not watertight geometry when converting it to a volume. Is this true?

In this case, I used Fuse, but it still didn't improve. It's a NURBS torus though. Here is how it looks:

Thanks

Edited November 27, 2013 by magneto

[koen]

This looks very much like artifacts you would get in the iso-offset node. I would try to use vdb from polygons.

Cheers,

Koen

[magneto]

Thanks koen, it works great I didn't know they were different in how they create volumes. Do you know if I can convert it back to a regular fog volume from the VDB?

[SpencerL]

It doesnt look like your object is manifold and/or you need to turn laser scan off. As Koen mentioned, using VDB is a bazzilion times faster than using the isooffset SOP.

[mawi]

Thanks koen, it works great I didn't know they were different in how they create volumes. Do you know if I can convert it back to a regular fog volume from the VDB?

Use the vdb convert SOP

[magneto]

Thanks I tried it but I was trying to convert VDB SDF into a fog volume so I thought it didn't work. But when I set VDB to fog before converting, then it works.

It's just all of them has different ways to do the same thing, so that's why I am still getting used to it

[edward]

VDB From Polygons can directly generate a fog volume. Disable Distance VDB, Enable Fog VDB.

[Annon]

Just using normal isooffset, if you turn laser scan off it'll stop the streaks.

What I usually do with multiple objects is run them in a foreachSOP to create the individual pieces then merge them into one, works very well for complex geometry (also finding edges and doing a polyCap on them if they're not solid).

C

[magneto]

Thanks Edward, that's what I ended up doing

Thanks Christian. That's a neat idea. Seems more reasonable than trying to get the whole shape at once.

How do you manage volume resolution though? I know you supply one for the Volume Merge but inside the Foreach, what resolution do you use for the individual pieces? If you use too much it will be lost in the end, no?

Edited November 28, 2013 by magneto