Motion Blur and MultiMattes

[hooperized]

I'm currently trying to adjust colors on a shot that has a heavy amount of motion blur but the multimattes don't fully cover the objects that they're matting, leaving a significant halo around the objects.

Does anyone know how to get full coverage in the multimattes for Motion Blurred frames?


Working in Nuke, 32 bit float exrs, renders from 3ds max using physical camera with motion blur



Thanks

[vlado]

You will need the multimatte element to be unfiltered if you want better coverage; that's not enough though - you'll have to tell V-Ray to get the element from the object closest to the camera rather than from the object with the most coverage. Can you tell me which 3ds Max version you are using?

Best regards,
Vlado

[hooperized]

Hey Vlado,

I'm using Max 2012. Also if it's unfiltered will it cause problems if it's a matte for only a part of the object that's moving? As far as premultiplying it so it doesn't affect the surrounding objects.

Thanks
Sean

[Morbid Angel]

I think your best bet, if you wish to get exact is to render this obj separate completely independent from other objects. Since even if you were able to get good matte of the edges of the motion blur, you still will color correct the geometry that is visible behind the object, which is not something that you would want.

[vlado]

Dmitry is right of course; in 3ds Max this is easy to do with the object select element; will make sure that we add it to the Maya version too.

Best regards,
Vlado

[Morbid Angel]

Dmitry is right of course; in 3ds Max this is easy to do with the object select element; will make sure that we add it to the Maya version too.

Best regards,
Vlado

That would be great!

[hooperized]

Thanks for the responses. It's what I feared, there's no way to really do a back to beauty build with heavily motion blurred footage, either the matte doesn't cover to whole objects or it ends up causing it to color correct other objects that it's blending with. Unfortunately I'm stuck trying to figure out patches for this since I'm comping this project.

Thanks

[Morbid Angel]

so why not separate the object and render it on its own?