[polynurb]

i don't quite get this:

i have a camera animation (no objects in motion) and i want to render a motion pass for post comp.

as far as i understood the manual, this pass reflects movement of objects in camera space.
if only the camera moves objects still move in relation to camera space or do i miss something here?

i can get the pass to work with objects being animated but i can't get it to work with camera only movement.

basically all frames will have a single color in the output, no matter at what speed the pixels travel over the camera plane:

with motion blur

with motion vector pass
and the channel output

[JDHill]

The docs should probably be re-worded to make it clearer that the motion vector channel is only concerned with object movement -- objects for which multiple positions have actually been written into the MXS. And where it refers to camera space, it should probably say pixel or screen space, since the motion vector format indicates pixel movement, encoded as 2D vectors in the red/green channels. As far as I know, camera motion blur is disabled if motion vector channel is enabled.

[polynurb]

thank you Jeremy,

i read on about the subject and this is not so straight forward when looking at other renderers.
some can do it some can't or only with special shaders and other hacks.
anyway a little notice in the manual would make things a little clearer imho.

d.

[Mihai]

I changed the page about this channel but we will try to add more detailed info on how to use it.