SOLVED: OpenCL Volumetrics, Cycles, Radeon RX580 .. Won't Work

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#1

SOLUTION: Install Blender using the .msi installer, not via the .zip download. This works for 2.79b official, but I have not yet tried using the most recent Blender 2.79 build.
So do volumetrics in Cycles not work with OpenCL or what?
I just bought a Radeon RX580, upgrading from a GeForce GTX560 Ti … Running Win 7 Pro 64-bit
In the official 2.79b, I create a cube then apply a simple volumetric scatter material to it. Renders fine with CPU, but when I try to render with GPU I just get a black box. This is in the viewport.
In both 2.8 and the most recent build of 2.79, when I do exactly the same thing, the render (viewport) hangs on sample 1. Sometimes I can go back to Shaded mode, other times Blender goes into “Not Responding” and I have to shut it down via the Task Manager.

I also just now tried doing an actual render, rather than just viewport rendered mode, using the most recent 2.79 build. I initially had it set to use both CPU and GPU, and it did indeed start rendering. However, only the tiles being rendered by CPU were actually rendering. I then went in and turned off CPU/GPU combined rendering, leaving only GPU on. When I again tried to render, it hangs up immediately: 0/40 samples. (EDIT: Correction. It did eventually finish one tile. It also told me the estimated render time is like 16 hrs. Which is insane seeing how the CPU can render it in like a minute or so)
No errors or anything unusual in the console.

This is very disappointing, as volumetrics is one reason I wanted to upgrade my GPU, and it worked just fine with my old GTX560 Ti :frowning:

#2

It used to be (pre 2.79) that AMD cards could indeed not do volumetrics, but as of 2.79 it’s claimed to be supported here:

https://docs.blender.org/manual/en/latest/render/cycles/features.html

Yours sounds broken, but I don’t have an AMD card to experiment with so I don’t have any personal experience ass to whether it should work or not. Any chance there are still some Nvidia bits installed on the system that are confusing it somehow?

#3

It’s a brand new card, and (so far) this is the only thing that’s not working as expected. Everything else (other software, everything else in Blender) works great and is way faster than my old GTX560 Ti … So I’m quite sure it’s not broken.
Pretty sure I cleaned my system up from the nvidia stuff, but I’ll take another look.
Been talking to some people on IRC #blendercoders as well. I will submit a bug report. Tomorrow. Right now I’m just really discouraged and mentally exhausted. All I wanted to do was muck about with volumetrics and enjoy the speed of my new card, but instead had to beat my head against this issue :frowning:

#4

The problem turned out to be that – as I’ve done for the last 2 decades – I installed Blender using the .zip download.
After having issues using ProRender and being finally told they can only support the .msi installer version, I went ahead and installed that alongside my other .zip installs.
LO AND BEHOLD! Volumetrics now works fine. And nice and fast. Yay.
Pretty odd tho. I’d consider this a bug, personally.
Regardless, I’m happy it now works properly.

#5

That’s interesting. Also because there are no .msi installers for either 2.80 or 2.79 experimental currently.

Would be great to know why this makes a difference. Maybe the known install location, or it’s looking for some registry key to see the installed location.

There can be issues with Zip installs in high-security environments for Windows where code is only allowed to run from specific approved locations like where the msi installer puts stuff.