Motion Vector excludding inside edges
by yesael sumalave
on
Oct 15, 2009 at 9:40:56 pm
Hi guys,
I'm having a problem with rs motion vector. I uploaded an image to help explain my problem: HERE
In image 2 the motion blur is correct when its over the alpha, but not on the inside part. THe inside looks like it wants to create a blur but then it stops at a hard edge. Is there any way to fix this? I want it to look like image 4 but nothing seems to be working.
What's even more strange though is that image 4 came from the lower part(same frame) of image 2 so it's doing it right and wrong on the same layer with the Motion vector applied.
Re: Motion Vector excludding inside edges by Pierre Jasmin on Oct 15, 2009 at 10:58:11 pm
Looking at the example you just sent
1) You should work with 16b motion vectors pass (eg tiff 16 bpc) and a 16 bpc or floating point AE project (then also make sure there is no color management on the MV sequence). (zero motion is not properly defined at 8 bpc etc)
2) When you have multiple layers like you do, you sometimes with post-motion blur need to split in a foreground and a background pass (2 color renders) so the motion blur works as expected.
I am not sure what your animation looks like but in this case you might be able to do something with just an alpha of the foreground layer. You would apply RSMB as you have it now then overlay a second pass where you would cut out of the MV alpha the part that is not in the additional matte you rendered and motion blur just the foreground with that.
Re: Motion Vector excludding inside edges by yesael sumalave on Oct 16, 2009 at 2:16:55 pm
So if I understand this correctly, I would have to have a separate motion vector pass for each moving object in the scene. Other wise objects that intersect will not blend with each other.
Re: Motion Vector excludding inside edges by Pierre Jasmin on Oct 16, 2009 at 8:31:13 pm
It's a process that works best on a layer basis
It's often not an issue if it's just camera motion but if a foreground object is over a static background you might have issues with the mb being cut-off yes
