Render Hangs
Moderator: juanjgon
I frequently get this render hang. Renderer loads scene and then nothing happens. Using 2015.2 & 2.22.1. Several of our scenes have a lot of instancing. Any idea what's up?
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A GPU memory problem perhaps? ... You have less than 2 GB of free GPU RAM available for Octane, and a very complex scene (near 15 MPolygons and 80.000 objects). Even with the Out-of-core to manage the textures you can have memory problems.
If you are using your display GPU for rendering, try to disable it. The GPU used for display can have a lot of GPU memory used by the Layout OpenGL and from other programs, and can reduce a lot the free available GPU RAM that can be used for rendering. If you need to use your display GPU for rendering, it is better to have a points or bounding box display in the Layout viewports, or even better, use LWSN for rendering, that doesn't fill the GPU memory with OpenGL buffers at all.
Anyway, please enable the log file to see if we get any Octane or CUDA error message.
-Juanjo
If you are using your display GPU for rendering, try to disable it. The GPU used for display can have a lot of GPU memory used by the Layout OpenGL and from other programs, and can reduce a lot the free available GPU RAM that can be used for rendering. If you need to use your display GPU for rendering, it is better to have a points or bounding box display in the Layout viewports, or even better, use LWSN for rendering, that doesn't fill the GPU memory with OpenGL buffers at all.
Anyway, please enable the log file to see if we get any Octane or CUDA error message.
-Juanjo
Why do the number of objects increase with instances? 80,000 objects? 99% of those objects are instances. I thought using instances was supposed to reduce memory load.
Sure there may be a lot of polygons, but they're all sharing a very few number of image maps.
Disabling the display GPU didn't help. The log file doesn't say anything.
I think this is more than a memory issue, but I'll try the same scene on our Titan Black machine and report more soon.
Sure there may be a lot of polygons, but they're all sharing a very few number of image maps.
Disabling the display GPU didn't help. The log file doesn't say anything.
I think this is more than a memory issue, but I'll try the same scene on our Titan Black machine and report more soon.
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The Titan Black computer renders the scene no problem with out of core off. It reports memory as being 3083/2330 Mbytes with the display card off.
I've tried the gtx 770 computer with both F9 & F10, and the display card is disabled. Both times it hung and both times the Octane log contained no information at all except what time the render was initiated. With F9 no memory information was displayed in the render window, but with F10 memory use was reported as 1567/315. Out of core was turned on, but it had zero use. At some point the 770 is getting stuck.
I understand that it's probably a memory issue, but it would be nice if there was some way to determine what limit was surpassed and how to avoid passing that limit. With this test it appears as if the 770 is getting stuck before it can even utilize the out of core feature, and it might be because there are too many instances.
I've tried the gtx 770 computer with both F9 & F10, and the display card is disabled. Both times it hung and both times the Octane log contained no information at all except what time the render was initiated. With F9 no memory information was displayed in the render window, but with F10 memory use was reported as 1567/315. Out of core was turned on, but it had zero use. At some point the 770 is getting stuck.
I understand that it's probably a memory issue, but it would be nice if there was some way to determine what limit was surpassed and how to avoid passing that limit. With this test it appears as if the 770 is getting stuck before it can even utilize the out of core feature, and it might be because there are too many instances.
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The instances are using really low memory while rendering the scene, perhaps only a few floats each for the transformation matrix, but they are reported in the statistics as full objects. Perhaps the Octane API should report in two values the number of instances and the number of real objects, but this values are not available yet.hdace wrote:Why do the number of objects increase with instances? 80,000 objects? 99% of those objects are instances. I thought using instances was supposed to reduce memory load.
Sure there may be a lot of polygons, but they're all sharing a very few number of image maps.
-Juanjo
So your scene needs 3083 MB of GPU RAM to be rendered, this is why it can't be rendered in your GTX 770 GPUs that have only 2 GB of GPU RAM. Out of core can't help of the physical objects geometry, plus the acceleration structures, frame buffers, passes, etc. don't fit in the GPU memory.hdace wrote:The Titan Black computer renders the scene no problem with out of core off. It reports memory as being 3083/2330 Mbytes with the display card off.
I've tried the gtx 770 computer with both F9 & F10, and the display card is disabled. Both times it hung and both times the Octane log contained no information at all except what time the render was initiated. With F9 no memory information was displayed in the render window, but with F10 memory use was reported as 1567/315. Out of core was turned on, but it had zero use. At some point the 770 is getting stuck.
I understand that it's probably a memory issue, but it would be nice if there was some way to determine what limit was surpassed and how to avoid passing that limit. With this test it appears as if the 770 is getting stuck before it can even utilize the out of core feature, and it might be because there are too many instances.
I agree that the plugin should help with the GPU memory issues. A message like "Your scene needs X GPU memory, but you only have Y memory available" could be fine. I will ask for this feature to the Octane developers, because I am not sure if this problem can be managed now by the Octane API.
-Juanjo
If the scene needs 3083 MB of GPU RAM, how do I know the difference between the ram required for object geometry and image maps?
Anyway, your message idea would definitely help.
Thanks Juanjo!
Anyway, your message idea would definitely help.
Thanks Juanjo!
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I'll tell you what's really driving me crazy right now. I've got a scene with a forest and some characters. With one of the characters missing the scene renders normally and the memory statistics are thus: 3571/1575. So that's supposed to mean there's 1575 MB free in the Titan Black (display card disabled). The missing character, when rendered completely on its own only uses 275 MB. So I add the character to the scene and suddenly there's the memory hang. I shouldn't have used up that 1575. There should still be 1300 available.
A completely different character in the scene, who was already in it when it rendered normally, is then removed (with the new character remaining). Suddenly the scene renders no problem. I test this character completely on its own and he only uses 225 MB.
Clearly there is no specific problem with any of the characters (I've tried several different ways of testing this). So some sort of threshold is being breached when the scene is full, but I can't see it because Octane reports there's still some GPU RAM free. That's why I keep thinking there's a bug that isn't directly related to how much RAM I'm using.
A completely different character in the scene, who was already in it when it rendered normally, is then removed (with the new character remaining). Suddenly the scene renders no problem. I test this character completely on its own and he only uses 225 MB.
Clearly there is no specific problem with any of the characters (I've tried several different ways of testing this). So some sort of threshold is being breached when the scene is full, but I can't see it because Octane reports there's still some GPU RAM free. That's why I keep thinking there's a bug that isn't directly related to how much RAM I'm using.
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What are the LW subdivision settings of the characters, or are you using the Octane OpenSubD? ... perhaps at render time you are subdividing the mesh with a lot of steps.
Do you have the same problem with the IPR and with the final F9/F10 rendering?
Octane should work without problems as long as it has about 200 or 300 MB of free GPU RAM.
-Juanjo
Do you have the same problem with the IPR and with the final F9/F10 rendering?
Octane should work without problems as long as it has about 200 or 300 MB of free GPU RAM.
-Juanjo