Motion Blur with changing topology: HOW TO?

[PsychoSilence]

What's the best way for motion blur setting wise if you have changing topology?

Since max2010 the cloth modifier features tearing:
http://joegunn3d.com/Tuts/TearCloth_2010.htm

and with the Particle Flow Toolbox#2 out we are able to do stuff like this with ease:
http://vimeo.com/7820773
http://vimeo.com/7086699
http://vimeo.com/7820673

But how can we render scenes like that with vray motion blur? I'm open for discussion and ideas from the masters minds in this forum Every pure Raytracer i've come across so far has issues with this. Hybrid renderer seam to get around it with a 2d/3d motion blur (semi-image mblur).

with kind regards,
Anselm

[Morbid Angel]

no way I know of. Multipass motion blur would be the only true motion blur. Also motion vector.

[PsychoSilence]

I know, but my point is that we should be able to render mblur in vray and not via the cam. I brought that up over at the orbaz forum as well. With the new service pack on the way we have the opportunity to make pflow and vray talk nice to each other once and for all i'm really interested in being more involved into this having a decent insight into pflow and vray.

[vlado]

If the object is a particle system, V-Ray will be able to produce accurate motion blur for it, even if the resulting mesh changes topology.

Things will also be fine if the topology changes from frame to frame, but is constant within a frame. Otherwise, you can increase the motion blur geometry samples for such objects to get an effect like multipass motion blur without re-rendering the entire scene.

Best regards,
Vlado

[PsychoSilence]

In box2 the particles are just the driver to tear a regular mesh apart. The ParticleSkinning is applied as a modifier. so it is an edit poly or edit mesh that needs to be blurred:

http://orbaz.com/documentation/parti...faceApart.html

i think an example scene would be good but my attachment is 4MB

[PsychoSilence]

i did a quick test scene here using image motion blur but that only seams to work nicely for stills...

the rendered image is a still just using the motion blur render effect.

the first screen shot is what i get when i wanna render a sequence (16 and/or 32bit EXR in my case)

the second screen shot is my exr settings (16bit in that case).

so when i try to render a sequence it just throws that error NOT taking into account the image motion blur (what i want in a future release is 3D motion blur anyways) rendering without motion blur. I attached the max2010-64 file using particle flow box2 in it's latest version, same goes for VRay and it's SPs. All i'm interested in is HOW can i render changing topology geometry (Glu3D, box2, cloth in max2010 supporting tearing) with proper motion blur?

kind regards,
Anselm

[jrandom]

...All i'm interested in is HOW can i render changing topology geometry (Glu3D, box2, cloth in max2010 supporting tearing) with proper motion blur?

kind regards,
Anselm

I concur

[PsychoSilence]

after a coupla emails with Oleg and Vlado back and forth here is a first test:
http://vimeo.com/10236817

Particle Skinner settings
Sustain Topology [checked]
Interval Ticks: 80

VRay MBlur settings
duration: 0.5
interval center: 0.25
bias: 0.0
samples: 6

Excerpt from the Box2 online documentation:

Sustain Topology - When on, you can set a time limit for changing the modified object's topology. This is important when rendering with image motion blur; otherwise you can safely ignore this setting.

* Interval Ticks - The time interval (in ticks) during which the topology holds its consistency. The default value is 10; this is usually sufficient for most renderers. For example, to calculate motion blur, the default scanline renderer takes two snapshots of the object geometry four ticks apart to define the overall geometry change.

Note: In 3ds Max, a tick is a very small time interval, of which each second contains 4,800.

kind regards,
Anselm