I’ve been searching around the internet to see if Krakatoa supported rendering particles between different types particle displays, similar to Maya’s hardware particle types such as streaks. Before using Krakatoa I had rendered many particle systems using streaks instead of points for a “fake motion blur” effect without having to use motion blur.
Is this possible with Krakatoa? Using actual motion blur is not possible for my project since the geometry holdouts will get blurred as well.
The way we have rendered streaks in the past has been to use a “Velocity” channel to define the direction and length, then enabling motion blur. You are right though that this will also blur the holdouts. This is sort of an unintended side-effect of enabling motion blur in this case.
Krakatoa doesn’t currently have an option to disable motion blur for holdouts. If we added that option, then you could achieve this look. Is that something that you would like us to add? If so, I can look into putting it in for the next release.
A hacky way to work around the problem might be to change the shutter angle to something like 0.0001, then scale your velocities by 1000. That would almost zero out the motion of the matte objects. I don’t really recommend this, but it might work for a test.
That would be a neat feature, and would be sort of an upgrade from Maya’s default streak particles since the tails don’t deform with a sudden change in velocity. I might try out that test when my deadlines aren’t so tight and get back to you on the effectiveness.