I just made this video to show the reasons for this ugly bug.
Any time you render a close shots of the hair, or any other object with dense opacity maps, you get ugliness when:
1. You render with full screen, or fairly large view-port.
2. You enable Super Sampling
Question: How to overcome those artifacts without disabling SS?
Answer: Render with SMALL view-port. The size of the view-port should be determined experimentally.
Here is an example:
My screen resolution is 2560x1440px and I am rendering 1920x1080px video
Demo video contains three, 3 seconds repeated clips.
Clip1 - Render with "Optimize with Full Screen Render" and SS 3x3 enabled. Result - is horrible hair opacity artifacts.
Clip2 - Render with "Optimize with Full Screen Render" checked , but no SS. Result is better, but artifacts are still there.
Clip3 - Render with SMALL view-port and SS 3x3 enabled. Result - all artifacts are gone.
Here is how view-port looked like when I fired up Export for clip 3:
Full screen / large view-port size renders have certain advantages such as smoothing jagged edges on some objects with enabled glow, suppressing GI flickering.. etc. And it is faster.
But when it comes to close head shots with certain hair, it is just unacceptable.
I usually render close shots separately from the rest of the video for that reason.
3 Years Ago by