i encountered some issues with an animation. Out of 101 frames 46 look like the attached one. They get seemingly inverse coloured square artifacts all over. The attached one is the worst of them all, some are artifacted to a lesser degree or more monochromatic. In final render output the squares on most images get black, but in the viewport or render preview they are always colourful like shown.
up on request i could share the .ksp - but i as well opened a support ticked where i attached the .ksp for the luxion team
there are 5 physical light sources: an area light + a spotlight, both animated with a fade curve and colour fade. The Spotlights poition is animated as well. And 3 area lights static in the light. Turning all animations off provided the same results.
its rendered without caustics, in interior mode. 30 samples with denoise at .4 . The Artifacts get worse with more samples though. And they do seem to not appear in product mode.
AMD Radeon 580X Pro
Same for me,
iMac 2020 i9 10 cores
Radeon Pro 5700 XT 16GB
On my side, the issue does not affect final renders but viewport only (some renders fired, not a deep test, but they are fine). It starts about around 30 samples as Sam say above. The issue does not affect my old (vintage) machines, Mac Pro and MacBook Pro Running KS under Mac OS High Sierra.
Both have a obsolete AMD Radeon Graphics card.
When I've experienced this issue on my new iMac in September I thought it was related to a known 5700 XT 16GB driver issue recently fixed by Apple in last Catalina update...
GB (Radeon Pro 5700 XT) GDDR6
16 GB (Radeon Pro 5700 XT) GDDR6
iMac Pro 2017
2,5 GHz 14-Core Intel Xeon W
Radeon Pro Vega 64 16GB
worked fine on iMac but no longer on iMac Pro.
Interior mode and area/emissive light may cause problems...
Any news yet?