biased path adaptive rendering very slow

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Re: biased path adaptive rendering very slow

Postby Dade » Sat Mar 14, 2015 5:12 pm

bertrand wrote:Found another problem memory-wise: If you render the default cube at standard resolution (1920*1080) with a tile size of 8 in bias path CPU, it takes 1800Mb memory on windows 64. Blender reports 64mb where used with 120mb peak (already pretty high for rendering the cube) so you have to check in the task-manager.Using latest Luxblend, latest Blender and latest BYOB build.


Blender knows plain nothing of the memory allocated by LuxCore (geometry, textures, frame buffer, etc.).

I'm quite sure also that the reported amount of memory used by Blender includes only few buffers allocated by Blender itself: Blender alone with the cube scene uses far more that 64/128 MBs.
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Re: biased path adaptive rendering very slow

Postby B.Y.O.B. » Sat Mar 14, 2015 6:39 pm

bertrand wrote:@BYOB thanks for the quick answer. I wish I could help, but my Python knowledge is really basic. Note that for the cube, the problem is more the huge memory needed (1,8Gb) is more problematic than the wrong reported memory usage.

Ah, sorry, was kind of tired. I'll test this scenario tomorrow. I suspect that the memory usage simply comes from the film/framebuffers. Will compare to Cycles, I think we might have some duplicate framebuffers.
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Re: biased path adaptive rendering very slow

Postby Dade » Sun Mar 15, 2015 4:22 am

B.Y.O.B. wrote:Ah, sorry, was kind of tired. I'll test this scenario tomorrow. I suspect that the memory usage simply comes from the film/framebuffers.


Yup, it is here: https://bitbucket.org/luxrender/luxrays ... ault#cl-80
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Re: biased path adaptive rendering very slow

Postby bertrand » Sun Mar 15, 2015 7:16 am

Hi all, after comparing with official 2.74 build and the AS build from Lukas Stockner (patch here https://developer.blender.org/D808 and latest build link here: https://dl.orangedox.com/CqmcYSd7e5XyAL ... 1_CUDA.zip), both official and adaptive versions need less than 3 mb to render the cube in 1920*1080 with a tile size of 8 (not regarding the reported memory of 0.3 but the difference in memory usage in the task manager going from about 184MB to 186MB.) As cycles only renders every tiles once, I checked with Corona, which has the same strategy as Lux (render in several passes). Corona needs 70MB at 1920/2*1080/2 and 270MB at 1920*1080. That's pretty high compared to Cycles but using progressive or tiles of 32, 16, 8 or even 4 makes no difference in memory usage.
The workaround at the moment with Lux is to render with big tiles and avoid high resolution. Problem is that the differences in noise level become much more visible and performance on CPU also drops after going above 16x16 pixels tiles.
@Dade, is it possible to reduce the memory usage or is it inherent to the way your tiled rendering works?
All values mentioned where taken in the task manager for fair comparison.

For the Memory leak on heavy geometry scenes, I found some other subjects where the same problem was found: http://blenderartists.org/forum/showthr ... ost2431531. The problem start to be mentioned here: http://blenderartists.org/forum/showthr ... ost2385963 . I Hope it is not related as they didn't found a solution then (2013).

Edit: After reporting the bug on the Blender Bug tracker, Bastien the leak is not due to Blender. I have no Idea, so I guess if you notice it is not on your side, we will need some arguments :(
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Re: biased path adaptive rendering very slow

Postby bertrand » Sun Mar 15, 2015 10:51 am

Just to clarify things, I really find Luxcore great. I just would find it sad, when such a great render isn't used more, just because of 2 memory problems. Please find a fix :)
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Re: biased path adaptive rendering very slow

Postby bertrand » Thu Mar 26, 2015 3:53 pm

Most bugs I found are reported on the tracker. I'm not sure for many if it's LuxBlend or LuxCore, so feel free to correct. I hope I didn't forget too much.
Have fun first and nice job :)
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Re: biased path adaptive rendering very slow

Postby B.Y.O.B. » Thu Mar 26, 2015 4:08 pm

Thanks for adding the bug reports :)
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