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spheratu
10-28-2003, 08:08 AM
Hi,is there a way to apply motion blur to a sequence of frames?
no transform nodes will be applied.I just want to render from maya a sequence without motion blur and apply it in shake.
Is it possible? do I need layers or can the blur be applied to a single layer sequence?
Thanks!

arvid
10-28-2003, 10:08 AM
It's not possible with the default toolset. You would need something like 'smoothkit' and you'd also need to output vectors coded into rgba or in a rla-type data format. But Im not sure what's available for Shake in this regard.
Another approach is Reelsmart:Motionblur, which is based on optical flow and thus doesn't require externally created motionvectors.
Hope that helps :)

beaker
10-29-2003, 06:48 AM
Read the fan tutorial that comes with shake. Pretty much you track parts of a moving object and use that to drive the motion blur. A more manual way to how reelsmart motionblur works.

arvid
10-29-2003, 08:21 AM
That's fine for simple spinning objects and so on, but it wont take you very far.. about as far as radial and directional blurs will take you. It'll looks a bit better tho ;)

beaker
10-29-2003, 08:33 AM
No, not true.

Blue Sky used this method for all their motion blur in Ice Age. They showed it at siggraph a few years back.

arvid
10-29-2003, 01:08 PM
Interesting, I had no idea.. how would one go about applying motionblur to say a running character?

FClub_TDurden
10-29-2003, 06:35 PM
beaker said:

"Blue Sky used this method for all their motion blur in Ice Age. They showed it at siggraph a few years back."
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Actually this isnt true.....They had issues in there renderer with there 3D motion blur for the teaser/trailer and had to use this 2D fake motion blur as a last resort....however after they worked out there 3D motion blur kinks...they used that for the whole film....

This tracking 2D motion blur is only good for side to side or up and down motion blur (2D space)....it doesnt work for anything more then that though..

beaker
10-29-2003, 10:31 PM
My bad, it was just the trailer not the entire film. It still looked pretty good.
Originally posted by FClub_TDurden
This tracking 2D motion blur is only good for side to side or up and down motion blur (2D space)....it doesnt work for anything more then that though..
This method is essentially how ReelSmart Motion Blur works but in a more manual way. It tracks the motion of objects in the scene and uses that information to drive the MB. I don't see how it is any different. If it works for Reelsmart then it will work for this. It just takes a little longer to do. Sometimes there are artifacts, but for the most part it works just fine.

FClub_TDurden
10-30-2003, 01:45 AM
beaker said:

"This method is essentially how ReelSmart Motion Blur works but in a more manual way. It tracks the motion of objects in the scene and uses that information to drive the MB. I don't see how it is any different"
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Well Reelsmart is very different then the shake hack....Reelsmart is doing a per pixel track and not a whole object track like what you do in Shake....you put a tracker on the layer or single elements and it blurs that whole element the same based on its total movement in 2d...where as Reelsmart is tracking the individual pixels and blurring them accordingly...visually its very different for motion blur to be more on parts of objects that are moving faster.....like just a fast hand move....there is no way to do this in shake with the 2D track blur....

arvid
10-30-2003, 08:26 AM
Thats what I thought as well.. it doesn't sound very realistic to add post-motionblur to an entire flick using this technique.. plus they'd need an enormous 'round-the-clock staff just to fake mb :p
With MR its possible to use per-vertex-motionvectors coded in rgb channels with a compiled shader to drive smoothkit in afterfx though. That's one of the most interesting post-moblur solutions I've seen, from an XSI/mr perspective :) French post-house LaMaison shared their motion vector shader on the XSI-list a couple of months ago.

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