mip_motion_vector with nuke?

[achoury]

Hello,

I'm trying to configure a motion vector pass using the mip_motion_vector shader. This project is composited in Nuke and I'm having some issues getting it to play nice with Nuke. Has anyone been able to configure the shader and get a pass to work with Nuke?

Im using default settings, max displace has been set to 450. That's the only thing I set. I grabbed this value from the render output log, much in the same way that was needed for the LM2DV shader.

The pass is rendered at 32 bits. If anyone out there has used such a pass coming from the mip_motion_vector production shader, any help will be appreciated.

yes the setup is correct just add the pass you want like 2D motion Vector or 3D motion Vector and choose the Image format, take a look at the attached scene
that's all

beauty pass iff format
http://www.postmyimage.com/images/imagesgnR50909.jpg

motionvector exr format
http://www.postmyimage.com/images/imagesJ7s51088.jpg

/rachid

[daddyo]

Thank you Rachid, I guess the pass is setup properly on my end. My Nuke artist is having some trouble getting a blur from the pass, however. What is the setup like on the Nuke side?
Also, I cannot open your scene. I get an error in Maya 2008.

[achoury]

Thank you Rachid, I guess the pass is setup properly on my end. My Nuke artist is having some trouble getting a blur from the pass, however. What is the setup like on the Nuke side?
Also, I cannot open your scene. I get an error in Maya 2008.

Hi
I think you can achieve the same thing in nuke, just add a node ReelSmartMotionBlur3Vectors here is my setup in fusion with default setup.

http://www.postmyimage.com/images/imageslZC38958.jpg

/rachid

[bbrcn]

When I tried render the motion vector to use in nuke, I set the floating point format to 1, other setting seem doesn't work properly in nuke. If you use nuke native vector blur node you have to watch out the alpha option it need to be the alpha channel of the motion vector.
Hope it works for you.

[leif3d]

The Motion Blur 2d Pass from Maya 2009 works great in Fusion, Maybe Nuke can read non-color vector information?

I could never get that MV shader to work in Maya pixel perfect, so I gave up and used iff vector information in 2008 and now the 2d blur pass in 2009, maybe it works for you.

[dg]

Just set it to either "RAW" or "Toxik" (Toxik seems to work just fine) and render to a float format.

By setting the "max displace" you're actually normalizing the vectors which is something Nuke doesn't like.

[YourDaftPunk]

Nuke expects the motion vectors to be in the range of -1 to 1. The motion vectors in Maya are being rendered in the range of 0 to 1. You can use an expression to move the vectors to the right value.

http://www.shawnlipowski.com/forumFiles/nuke_motion_vector.png
Change the vector blur method to 'backward' to get a result like rancid's screenshot, though 'forward' is more accurate. The only way to truly get the ball to look accurate in this example case would be to render with 3D blur and motion steps set to 4 or 5.

-shawn

[dg]

Just render in the correct format and forget about that expression. That expression is something I came up with a long time ago to use the lm2dmv shader normalized output in Nuke.

With the mip_motion_vector there is not need for it. Just set it Toxik and render it to a float format without any clipping going on.

[YourDaftPunk]

That's good to know!

[D4riel]

hey MEN where i connect the mip_motion_vector shader ......:S i don't know how to....¿¿¿

[achoury]

hey MEN where i connect the mip_motion_vector shader ......:S i don't know how to....¿¿¿

Read this thread (http://forums.cgsociety.org/showthread.php?f=87&t=706199)
/rachid

[D4riel]

hey THANKSSSSSSSSSSS