Ray Epsilon, Water, and Motion blur

[aggiechase37]

Couple questions:

1. I've noticed, but can't seem to find it mentioned anywhere, that ray epsilon can actually decrease render time when increased, but interestingly, when dealing with a liquid type surface with a specular material (as generated by the openvdb mesher in the new X particles, probably happens in other cases as well), lowering the rap epsilon value can increase the accuracy of the render. There seems to be a lot of detail lost when cranking this value high, but the render time goes down. Just an observation I wanted to throw out there and see if others had a similar experience.

2. I can't quite seem to be able to get the openvdb mesher water simulation to output motion blur. I've cached my scene, dropped an octane object with transform/vertex selected, camera motion blur enabled with 180 degree shutter equivalent, and nothing. Anyone scene this behavior? Know a fix?

3. Also, the mesh created in the picture viewer and the one in the live viewer are not even close to the same. The one in the live viewer is accurate, the picture viewer is like it is getting held back. I'll include a screenshot.

[3DRenderTom]

Hi,
after searching for quiet a while I found out that octane motion blur doesn't work on
geometry that has changing vertices (like the vdbmesher). Doesn't work in cycles either btw.

Cheers,
Thomas

[bepeg4d]

Hi Thomas,
if the number of vertex is changing during animation, you can use the sub frame trick:

Since the max sampling is divided by the number of passes, the rendering time is almost the same.
ciao beppe

[3DRenderTom]

Great! Thank you very much, very helpful!

Cheers,
Thomas

[aoktar]

Other way for mblur on this kinda meshes are "Vertex speed" option in objecttag->motion blur. Fill x/y/z components by proper vertexmaps and get mblur.

[3DRenderTom]

I don't think this works with X-Particles as there doesn't seem to be a way to gain access to the vertex speed. Theres now a Vertexmapmaker
but I haven't been able to get this to work.

[aggiechase37]

Can someone please explain how to generate proper vertex maps on xyz? Thank!