Rendering Error / Glitch - How to Fix / Reproduce

Sorry, wasn’t sure what section to post this under. The image fragment below shows bezier curves rendered via P2D with alpha non-unity and blendMode either BLEND or ADD, using processing 4 on Linux w a low spec Radeon card.

bad-render

You can probably see that there is some “striping” in some of the lines. This is unintentional and appears to be a glitch in how the image is generated. How do I avoid this and (even better) generate it on purpose?

Thanks,
Andrew

Hi @andrewcooke,

Actually the image you sent is really small (154x114) in resolution so I can’t really see any issue :wink:

Also can you post the code that generates this image? So that we can try it and debug if needed.

the resolution of the image is the same as the original, but if you want to look at more of it, here it is:

i was hoping it was a known issue.

if you want to run the code, i’ve placed a tarball at https://acooke.org/sketch_230623g.tgz - it’s rather complex and i would normally produce a minimal example before reporting a bug (but don’t have time right now - as i said, i was thinking it would be a known issue). that tarball won’t produce an identical image (i don’t know the random seed for the image i used here), but includes an image generated with the current seed (fixed in that code) with the same effect circled in red.