View Full Version : Max and La Maison vector shader

Peter Litwinowicz
08 August 2004, 11:40 PM
Has anyone out there been able to get motion vectors out of max using the La Maison Mental Ray vector shader for use in our ReelSmart Motion Blur plugin (that takes motion vectors in and blurs based on those motion vectors).

There was a posting here a few months ago about how to set up Max in order to get out motion vectors using the motion vector shader... however all I'm able to get is motion-blurred motion vectors. Not very helpful for what I want to do (let alone that these motion-blurred motion vector images are not accurate for post-processing the color images with our plugin).

Has anyone succeeded at getting motion blurred images using our ReelSmart Motion Blur plugin by getting useful motion vectors out of Max?
Pete Litwinowicz

08 August 2004, 11:18 AM
hey Peter,
now I know where those questions came from :)
yes, using the la maison shader is possible in max.
there are few rules of thumb you should follow:
1. all objects including the camera must be set to motion blur type:object (I`ll try image just to make sure)
2. make a new material and put the lm2d shader in the diffuse with self illumination set to 100%. drag this new material to the override material in the mental ray render dialog.
3. the lm2d shader has two modes of representing the shader use mode 1 not 0.
4. in the mental ray render dialog set motion blur on with segments=1 and shutter to 0 or as close to 0 :)
5. render beauty pass.
6. activate the material override and render to a different name *vectors.*
7. in after or combustion add realsmart motion blur and put the beauty pass with the effect and take the vectors from the vector sequance file.

the only drawback is that you realy render twice, not like other rendereres

08 August 2004, 11:44 AM
twice ?? you render a beauty pass and a vector pass, that's the minimun to get a 2d motion vector blur applied to a 'static' beauty image.. btw it takes less time and resources than make only a beauty pass with full 3Dmotion blur applied.. what the other renderer does in your opinion.. ?? :)


08 August 2004, 03:21 PM
other renderers let you save "elements"

in scanline you can use RPF to save velocity information as well as managing elements.
we`ve recently bought vray and it has its own elements/layers as well.

08 August 2004, 03:45 PM
ah ok.. sorry.. I'm with xsi.. I just put that 'elements' in a partition.. and apply lm2dmv to that partition... it's more a software issue than a renderer one.. that's why I was misunderstanding. :).. vray just try to overcomes that max limitation.. btw you cannot use lm2dmv with it ...:D


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