2D Motion Blur After Render

[ActionArt]

I know this is probably pretty basic but I haven't been able to quite put it together yet.

I need 2d motion blur on a large image but I don't want it applied automatically after render, I want to be able to render and then adjust the intensity. Is there a way to save the motion vectors and then apply 2d motion blur after rendering with existing SI software, maybe FX Tree or Composite? It's not important enough to buy any extra software but I thought it should be possible.

It's a very large image (9000x5000) and takes a long time to render so I don't want to re-render if the motion blur needs tweaking.

Thanks for any help

[Hirazi Blue]

Technically I don't see any problems there. Render a separate motion vector pass,
bring it into Autodesk Composite & use its vector blur facility to composite.
But maybe I misunderstand your question. If so, please elaborate...
;)

belated edit: This obviously wouldn't work for mere stills, as SI can't generate any Motion Vectors then (you caught me off guard by mentioning them in your original post, while the render resolution you mention seems to point at a still). In that case you'd have to resort to the standard blur options either in the FXTree or in Composite... But then you wouldn't have to generate any special pass and everything (tweaking the blur) can still be done as a post-process.

[ActionArt]

I'll give that another try. Last time I used it Composite/Toxic's display was corrupted and wouldn't work. I'll try it again with 2013sp1 and new video card drivers. I was hoping there was a node I was missing in the FX tree that would do it but back to Toxic it is then (that was an pretty good choice of names for that thing...the interface at least).

Thanks

[ActionArt]

Thanks Hirazi,

It is a still image but I have animated the objects in order to get the desired blur and then I just render 1 frame of it. 3D blur works fine but is painful slow. 2D blur works good for part of the image but the current output shader just applies the effect after rendering without the opportunity to adjust it if it's not right.

I've been fiddling with Toxic, got it working and it is not exactly straight forward. First off, it doesn't seem to import the native MR motion vector files so I assume there is some other format I can try but didn't get a chance today. I found a few rather confusing threads on the issue. It seems far from intuitive. Might not even be worth doing at all for this project, I might just use 3D even though it's slow.

[FXDude]

Using an old trick,
you could create a new pass,
and reapply your rendered image as a (constant) camera projection on your entire scene, ..

.. to then rerender, using either your 2.5d output shader,

-OR- "real" mr 3d M-B,
which would be somewhat slower,

but still very fast in those (constant) conditions
(& nicer looking:)

good luck!

[Nolan]

Just looking into this yesterday, but haven't tried it myself yet:-
http://download.autodesk.com/global/doc ... d30e679386
Maybe render with mip_motion_vector -> Floating Point Format = Toxik

Then for toxik motion vector workflow, see this free Digital Tutors video on "Blur Node: Vectors"
http://www.digitaltutors.com/11/trainin ... autoplay=1

[ActionArt]

@FXDude - thanks, yes I've used that trick a number of times but in this case it doesn't give the quite same results - I'll post a sample later, just out of the office right now.

@Nolan - thanks for the links! I'll give it a go.