Velocity pass render element

[Jussing]

To speed up rendering, I almost exclusively achieve motion blur through a velocity pass that I use in Nuke. (Of course this has limitations with reflections, shadows etc, but these are unnoticable in 99% of case, in my experience.)

However, I can't seem to get a proper velocity pass for Phoenix simulations.

I assume the recommended workflow is to always render Phoenix elements with motion blur, but are there any plans to support us velocity pass-dependent people out there?

Thanks
- Jonas

[Ivaylo Katev]

render in geometry mode, it is a bit slower, but gives all the render elements available for common geometry.

[Jussing]

OK, thanks...

I have tried the geometry mode before, but abandoned it for the transparency levels warning as well as a weird looking velocity pass.

I have made a small test here:
- Normal Vray render (no mblur): 23 sec
- With Vray motion blur: 41 sec
- Geometry mode, with velocity pass: 46 sec

Attached are a collection of screenshots that show the different results:
1) No motion blur
2) Vray 3D motion blur (has a motion blur-ish feel, but doesn't look real)
3) Nuke auto-interpolated vector blur (by far the best result)
4) Geometry mode velocity pass. Notice the hard intersections
5) Nuke vector blur using the velocity pass. You can see the artifacts where the intersections in the velocity pass are
6) Close-up (and exaggeration) of the artifacts from 5)

The three different solutions, sorted best to worst:
1) Compositing package auto vector blur
2) Vray 3D motion blur
3) Using the geometry mode velocity pass (serves no usable purpose, at least not in this test. Plus, it renders slower than 3D motion blur)

I have not, in this simple test, been able to produce production quality motion blur of a Phoenix simulation using any of the Phoenix or Vray features. The best solution seems to be to hope that your compositing package can successfully analyze a vector pass and add motion blur.

[Ivaylo Katev]

what version are you using? since few weeks we have changed the motion blur concept, the old one was simple but worse, now it looks significantly better.

[Jussing]

This is with Vray 3.0 demo and Phoenix 2.2 adv (3dsmax 2015). May releases though, not the nightly builds.

Thanks.

(I do not currently have access to nightly builds, but I sent a request yesterday, so I guess I might have it tomorrow)