# [Bf-committers] Cycles velocity

Manuel Rais manu at g-lul.com
Tue Oct 27 11:35:27 CET 2015

```Hi Sergey !

‌26 octobre 2015 14:14 "Sergey Sharybin"  a écrit:If it's just distinguishing whether there is motion or not then guess
object space would work. Perhaps could be something similar implementation
to the pointyness, but would nice to investigate if we can make it
something more generic.
100% agree with you for the more generic thing.
However, one question : is this velocity attribute on the vertices should be relative to the camera shutter of the scene ?
Will check on that in the upcoming days.
I'm also trying to look at the code but i'm a very very beginner so I've got no hope to solve this on my own at the moment.

So thanks again !

Manuel Rais
Autour de Minuit
manu at g-lul.com (mailto:manu at g-lul.com)On Sun, Oct 25, 2015 at 11:44 PM, David Fenner
wrote:
Hey. Nice idea to simulate stop motion. Saved in hard drive.

2015-10-22 6:41 GMT-03:00 Manuel Rais :
Hi Sergey

To be more clear, we want to use this attribute to switch from a texture
to another when the velocity is not null.
The purpose is to have a stop motion rendering with displace/bump
changingonly on the moving parts.
Of course there's many ways to achieve this but we're searching the more
automatic. We have others ideas of course but less funny ☺..

All objects in this project are baked in pc2 files and are at the center
of the world and their scale at 1. So I guess the world space and object
space are the same, but maybe I'm wrong.
I know a little bit of c/cpp maybe I can produce a patch (with a little
help?) if it's not too hard...

Thanks.

Le 21 octobre 2015 23:58:56 GMT+02:00, Sergey Sharybin <
sergey.vfx at gmail.com (mailto:sergey.vfx at gmail.com)> a écrit :What is the use of such attribute?

Also, due to instancing it's quite tricky to represent word-space
velocity
in the vertex attribute, only object space velocity is possible to be
stored without major PITA.

On Wed, Oct 21, 2015 at 8:07 PM, Manuel Rais  wrote:
Hi !

I was wondering if it's possible to have vertex velocity in the
attributenode of Cycles.
Cycles outputs velocity in the "Vector" pass, it renders motion blur
(object and deformation), so I guess that this attribute exists
somewhere...Am I wrong ?
Is it possible to add it in the output of the attribute node ? Is it
anightmare ?

Thanks.

---
Manuel Rais
Autour de Minuit
manu at g-lul.com (mailto:manu at g-lul.com) (mailto:manu at g-lul.com (mailto:mailto:manu at g-lul.com))
_______________________________________________
Bf-committers mailing list
Bf-committers at blender.org (mailto:Bf-committers at blender.org)
http://lists.blender.org/mailman/listinfo/bf-committers (http://lists.blender.org/mailman/listinfo/bf-committers)
--
With best regards, Sergey Sharybin

---
Manuel Rais
manu at g-lul.com (mailto:manu at g-lul.com)
+33 (0)6 62 29 80 86
_______________________________________________
Bf-committers mailing list
Bf-committers at blender.org (mailto:Bf-committers at blender.org)
http://lists.blender.org/mailman/listinfo/bf-committers (http://lists.blender.org/mailman/listinfo/bf-committers)
_______________________________________________
Bf-committers mailing list
Bf-committers at blender.org (mailto:Bf-committers at blender.org)
http://lists.blender.org/mailman/listinfo/bf-committers (http://lists.blender.org/mailman/listinfo/bf-committers)

--
With best regards, Sergey Sharybin
_______________________________________________
Bf-committers mailing list
Bf-committers at blender.org (mailto:Bf-committers at blender.org)
http://lists.blender.org/mailman/listinfo/bf-committers (http://lists.blender.org/mailman/listinfo/bf-committers)
```