gpu failed material

[bepeg4d]

I was trying to generate a more clear specular material but i've found that if you play with a mix-material with glossy with opacity < 1 and a specular with absorption with PMC kernel, all the gpu failed
ciao beppe

[t_3]

ups! seems to have some unwanted effect here too; might explain some problems i recently too had with pmc - need a little more testing...
ps: what sort of crash did you have? were you able to recover by just restarting octane?

[bepeg4d]

Thanx for testing, no crash, only gpu failed, restarting octane solved the problem
ciao beppe

[t_3]

Thanx for testing, no crash, only gpu failed, restarting octane solved the problem
ciao beppe

hm, no clear picture yet. testing your material the fail i had seems to be connected with my gpu clock settings; i have 2 factory oc'ed 580s, where i could render along with exactly this material and pmc, if i just lower shader & vram clocks (so it is not just the material setting causing a problem). on the other hand i still have a scene where the gpus fail after a few hundred s/pix with pmc (but not pt), even on nvidia default rates (or on other machines/cards). moreover other scenes using about the same material settings work still fine in pmc.

i tend to think that the pmc kernel has a few problems with some yet unknown settings/combinations, but imo it is not just this specific spec/glossy+opacity mix mat causing a problem right away - must be connected to other settings in your scene if you can that easily trigger it - maybe, if possible, attach the whole scene so it might be easier to reproduce the problem...

[bepeg4d]

i was working in an empty scene with only the material macro loaded on both mac and pc
ciao beppe

[t_3]

i was working in an empty scene with only the material macro loaded on both mac and pc
ciao beppe

but still render kernel and enviroment settings may have some effect; if you attach the whole .ocs it'll be interesting to see if i can reproduce it then; because when i applied the material to a simple sphere nothing happened. it started failing not until i applied it to all nodes of a more crowded scene...

[bepeg4d]

the scene is the default preview ball so you only need to open octane and load the ocm and switch from pt or dl to pmc
probably the external element that you are speaking about is an emitter, if i remember well the rs has added an emitter in the preview ball scene some version ago in fact i discovered this bug in a scene full of emitters
ciao beppe

[roeland]

I was trying to generate a more clear specular material but i've found that if you play with a mix-material with glossy with opacity < 1 and a specular with absorption with PMC kernel, all the gpu failed
ciao beppe

There is a problem with the PMC kernel with subsurface scattering, which causes it to crash on materials with both SSS and transparency. We will fix it in the next release.

--
Roeland

[bepeg4d]

thanks roeland for the clarification
ciao beppe

[Timmaigh]

Just happened to me to today, failed GPU. Unfortunately do not know, where the problem is, i do not think i have a SSS material with transparency on that scene. Just testing another scene and everything seems to be allright, both gpu working after cca 10 minutes, although this time its pathtracing instead of PMC. In any case, i was scared its some hardware problem with my GTX590, as i had it overclocked, but thank god its not - so it seems.

EDIT> God, i need the PMC fix NOW! I have an evening interior scene to render for tomorrow and the bitch! wont render it, both GPU fail almost immediately. Tried to render it with pathtracing, but it was just 10000 samples and noisy as hell.