Velocity pass

[Chakib]

Hi,

It would be great to add this pass to the corona elements.

[Midge]

Sorry to necro this thread, but how hard would it be to implement both object and camera motion blur into this pass.
It has always bothered me that you can only get object MB from it. :)

[chilombiano]

are you asking if it is possible to produce a motion vector pass that includes Z motion in order to get something similar to 3d motion blur? Humm .. It supposedly doable but calculating the 2d motion blur can be as or slower than proper mb.
Here is a good read about it from the nuke side. I don't think they got a perfect solution as we still use simple vector blur today. Maybe keymaster can check it out and give it some thought:
http://forums.thefoundry.co.uk/phpBB2/viewtopic.php?p=4501&sid=51cf24c848dc8e2a81880a6237d595c3
 

[Midge]

Interesting read, thanks for that!

[Captain Obvious]

Sorry to necro this thread, but how hard would it be to implement both object and camera motion blur into this pass.
It has always bothered me that you can only get object MB from it. :)

Velocity pass data should include ALL motion, both from camera and items. It does in modo, at any rate. I don't see any reason for why a renderer wouldn't include everything.



Edit: and actual motion blur isn't the only use for a velocity output. You can also use velocity to reducing flickering/noise in animations.

[racoonart]

I think there is no doubt that this is a useful and wanted feature. It's not a big deal anyways, so I guess it'll be included when keymaster finds some time to do it.

[Midge]

In Max, both the motion vectors from the render elements and the G-Buffer in the EXR's is object motion blur only AFAIK.
That's the reason why I resurrected the thread.

[Captain Obvious]

In Max, both the motion vectors from the render elements and the G-Buffer in the EXR's is object motion blur only AFAIK.
That's the reason why I resurrected the thread.

Wow, that's completely useless.

[chilombiano]

Of course it does. Nothing wrong with max there but the way you are understanding the issue.
Max per object motion blur is not anything close to motion blur but a trick to improve the look of the mb of a fast moving object.
From the max help doc:
"(Another option, object motion blur, is not meant to simulate a camera, but to improve the rendered appearance of fast-moving objects.)..."

"Object motion blur works by rendering multiple copies of the object in between frames and then rendering them together. It is not affected by camera movement.

Being said is not surprise it ended being part of any pass out of their old scanline renderer.

Now.. When you mention the motion vector pass i guess you mean the one that comes out of MR, right? Cos i can't remember max had one ( but is being a long time i use max scanline so maybe im wrong ). If you are talking about MR then it would simply be an error easy to fix by no using object mb at all.. There is just no point using that if your goal is to make your  mb in post.. That's why you are outputting a vector motion pass in the first place.

So. Having that definition of object motion blur as a feature in corona render just doesn't makes sense too much. As captain obvious said you get all motion data ( well, not exactly * ) from your velocity pass and if you mix that with z depth in nuke you'll get a fairly acceptable mb ( vector mb what they call )

It would be more interesting and much more important  as an addition in corona to implement EXR 2.0. Now that's something you can play with for your post mb!. And maybe p-ref data for experimenting with it though i'm not yet so familiar of how to use it.

Sorry for the long post guys :)
 

[Ondra]

Duplicate of http://corona-renderer.com/bugs/view.php?id=90

[darth_biomech]

Sorry to double necro this thread, but has this pass been added recently at last? Inability to create post-processed motion blur is a major setback for incorporating this render into my workflow, which is real shame, since it is ridiculously fast and can convert vray materials relatively painlessly.