Motion Blur stops rendering properly with high Samples
Posted: Fri Jan 27, 2017 10:59 pm
I'm rendering some fast spinning tires on a Formula 1 car and I needed to crank the Motion Blur Samples per frame from 1 up to 12. This achieved good results but I was surprised to find that my 300 frame render stopped rendering motion blur after 256 frames (the render finished… the motion blur just stopped at F 256). I checked for keyframe anomalies and even cached all expressions to keyframes but I got the same results.
Ultimately I decided to reduce the scene to a simple cube spinning for 300 frames with the same render settings to see if I could get the same results... and I DID! My spinning cube's motion blur changed at frame 256. I decided to double the samples to 24 and the motion blur changed at frame 128. It looks like it went from doing a bi-directional blur to a uni-directional blur… so there’s something unfavorable but predictable happening here.
Screenshot
Movie
File
Thoughts?
Ultimately I decided to reduce the scene to a simple cube spinning for 300 frames with the same render settings to see if I could get the same results... and I DID! My spinning cube's motion blur changed at frame 256. I decided to double the samples to 24 and the motion blur changed at frame 128. It looks like it went from doing a bi-directional blur to a uni-directional blur… so there’s something unfavorable but predictable happening here.
Screenshot
Movie
File
Thoughts?
