Rendering Artifact with Max Tile Samples

[wafflelad]

I have a scene where rendering with Max Tile Samples turned higher than 1 will create a hard line in the image. I've streamlined the project file to share it and in doing so narrowed the issue down to a cloner containing tree models. When the trees render, then the artifact happens. When I turn them off then it doesn't happen. Setting Max Tile Samples to 1 also prevents the artifact from happening. Any idea what's going on here? I can render with the tile samples turned down, but it takes longer. If nothing else, I thought it would be good to share this in case it helps point out a bug.

Without artifact:


With artifact:


Here is a screenshot mid-render showing clearly how the image is being segmented in the render:


The project file is here:
https://dl.dropboxusercontent.com/u/108 ... werFog.zip

[bepeg4d]

hi wafflelad,
I have tried your scene and it seems that I don't have your issue, but unfortunately it's difficult to judge because of teamviewer
which is exactly your hw setup?
In particular, do you have any GPU in a low speed PCI slot?
ciao beppe

[wafflelad]

This is my second issue that can't be reproduced. I'm starting to think my GPU may be a little unreliable, or the combination of it and my ancient Mac.

System:
2009 8-core Mac Pro / 32gb ram / OS X 10.11.5
Octane 3 R1.1
780 ti in slot one (x16) with external power
GT120 in slot two for displays

[bepeg4d]

hi wafflelad,
wait, I'm not sure, because currently I can only reach my workstations via teamviewer on an iPad, sorry.
The setup seems correct
I guess it will be the same, but could you try to export to standalone and compare the results?
ciao beppe

[wafflelad]

Ok, it took me some time to learn how to export to standalone. Also, for some reason it took over an hour to render a frame instead of five minutes. The issue is still there, though...

[v-cube]

Hello, I am experiencing similar issues in octane for Rhino, It seems that octane tries to identify zones which need more samples to clear than others and distributes its power accordingly.
Sometimes this seems to work OK but often I get nasty tile artifacts...

We need an option to turn this behaviour off ASAP!

attached an example picture (blue lines are PS ...)

[wafflelad]

Does it still happen if you turn Max Tiles down to 1? It seems to be a byproduct of how the tiling works.

[v-cube]

Does it still happen if you turn Max Tiles down to 1? It seems to be a byproduct of how the tiling works.

thanks wafflelad, this seems to do the trick... maybe there should be a warning in the flyout info of this setting, mentioning the possible tile problem.

best

Andreas

[wafflelad]

Yeah. Hopefully enough people have issues that they figure out a way to make the tiling work without artifacts, because it renders a lot faster with that cranked up.

[v-cube]

damm !

tiles again in a new scene - and this time reducing the sample value to 1 does not help...

I will create a new topic under general discussion, since this seems to be a general issue...

I really hope someone at otoy reads this and it gets fixed ASAP ...

Andreas