Maya 2d motion blur with mental ray?

[fahr]

Whoops! Sorry for the double post. :)

[Jozvex]

There's a file called blur2d.exe (or something similar) in Maya's bin folder that you can supply images to, and it'll blur them for you using the motion vectors you can save out from the Maya Software renderer.

Maybe you could create a 'motion vector pass' using just surface shaders on all your moving objects? Saving out the vectors from Maya Software and then have the blur applied to your actual MR render?

[fahr]

That's exactly what I'm wanting to do, but the blur2d help menu gives no information on how to use one image sequence (with motion vectors) to blur another. But I've heard that its possible to use blur2d for this purpose, I just dont know the command, unfortunately.

[Jozvex]

Try this page:

http://caad.arch.ethz.ch/info/maya/manual/Utilities/blur2d.fm.html

:)

[fahr]

I must be incredibly dim, here. I've looked at the blur2d help page a million times, and all I see is the commands to blur a sequence of images that already contain the needed motion vectors.

blur2d -f sphere.iff creates a sphere_blur.iff sequence.

What I think i need is something like this:

blur2d -f sphere_without_vectors.iff using box_with_vectors.iff (or somehting like that). ;)

But there is nothing that I have seen or tried that seems to do that. I noticed th -v flag, but that seems to be the same thing as the -f flag...

BTW, thanks for the help. Im going into work this morning to run a few more tests. I've tried this before and got nowhere, but i know its possible dammit! Everyone always says "use blur2d for that", so what am I missing? There's no apparent flag that allows me to do this, or is there?

Sorry in advance if the answer was always there and I was just too stupid to see it. ;)

[Jozvex]

Ok, I gave it a try just now and got it to work. Here's what I did:

I had two 20 frame image sequences, named Helix_Colour.iff.# and Helix_Vector.iff.#

This is the command I used to blur them:

blur2d -l 1.5 -s 1 -m 1 -n 1 20 1 -f Helix_Vector.iff -c Helix_Colour.iff

Blur Helix_Colour 1 to 21 using the vectors from Helix_Vector, with a length of 1.5, sharpness of 1 and smoothing of 1.

:thumbsup:

[lazzhar]

I used to motion blur them like that:
blur2d -l 1.5 -n 1 20 1 -f Helix_Color.iff -v Helix_Vector.iff

I saw that it's very sensitive to the padding of your files. So I stick to render to:
Helix_Color.iff.1, Helix_Color.iff.2, Helix_Color.iff.3 ....etc , and for the motion vector pass the same thing.
If you make the mistake of rendering the motion vector things to another padding format then better rerender it again instead of trying to convert in other programs. For example Combustion woulld make them unreadable by blur2d.exe

[fahr]

Thank you guys SO much!

I've been wanting to know how to do this forever!

Now i can use mental ray and maya software together and still have a consistent motion blur between the two.

Using mental ray and paint effects together in the same scene used to be murder if stuff started to move. :)

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