[Bf-funboard] Custom velocity data for motion blur

[Kévin Dietrich]

Le 2016-11-15 11:49, Gatis Kurzemnieks a écrit :

> Hi all.
> Would It be possible to implement using vertex colors as mesh velocity data
> for motion blur (that seems like most easy solution)
> It would allow importing meshes with changing geometry with Alembic (with
> vertex velocity stored as color) and render correct motion blur. It would
> be UBER userful for rendering cached fluid sims, particle systems etc.
> imported from i.e. Houdini.
> 
> Gatis

Hi, 

Vertex colors are stored in Blender using the face loops not the
vertices, this allows to have face varying colors, where the same vertex
connected to multiple faces can have multiple colors. So until we have
proper vertex colors stored once per vertex, using them for motion
bluring is not really feasible. Though it is a good idea. 

Alembic does have special storage for the velocity data so we could use
this information to do motion blur. I started working on a patch [1]
months ago, but couldn't finish it. At last check there was a couple of
issues, but if you can compile Blender, feel free to try it out. 

Cheers, 

Kévin 

Links:
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[1] https://developer.blender.org/D2388