Smearing pixels in 3d space

[zdimaria]

I am trying to achieve an effect for a project, and have no idea how to approach it. I need to take a render's normal pass, and use that to get surface tangents. Then I want to smear the color channel of the render, across the surface, in 3d space. The reason for this is to try and achieve a 'painterly' effect. Basically trying to make things look like impressionistic paintings. I will probobly do some sort of posterization first, but am not sure how to approach the smearing. I know vops, but have never done anything in cops at all. Do you think this is something that can be done in Houdini?

[ikarus]

A simpler alternative could be to turn your surface tangents into velocity values and blur your color pass with 3D Motion Blur.

[mightcouldb1]

I've seen this kind of stuff done with multiple render passes. Some combination of NPR(Non-Photorealistic Rendering) and motion blur. I saw an example from SIGGRAPH from a couple years ago that used oscillating surface displacement(1 oscillation per frame) that was motion blurred. Pretty cool stuff. You can really attack it however you want and achieve an interesting look. My suggestion is to find a painting with the look you're going for and work toward matching that look. Look at the structure of the brush strokes and think about a machine might recreate that structure.

This paper does it quite well, but it would probably be some heavy lifting to get this implemented. I'd use it as inspiration.

http://www.stat.ucla...ch/parse2paint/

And to answer your last question...

Anything can be done in Houdini.

Best of luck.

Edited September 22, 2012 by mightcouldb1

[mightcouldb1]

Just an addition to my above post. I came across this video today:

http://www.itsartmag.com/features/paperman-breakdown/#.UGtBvrTybin

Cool ideas!