Very noisy renders

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chafouin
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Re: Very noisy renders

Post by chafouin »

Dade wrote: Thu Jan 25, 2018 8:44 pm First of all, check your performance (i.e. samples/sec), your Titan should be quite faster than my 290X, is it ?
GPU only: 10.9M samples/sec - 196 seconds for 1000 samples.
GPU+CPU: 11.2M samples/sec - 185 seconds for 1000 samples.

Samples/sec value starts lower, around 5-6M samples per sec, and progressively ramps up to these values.

Exported a .bcf and tried in LuxCoreUI:
GPU+CPU: 12.5M samples/sec - 166 seconds for 1000 samples.

Samples/sec value starts around 8-9 and then ramps up to 12.5M samples per sec.
It's sad that Blender seems to be slower than LuxCoreUI, maybe it would be good to have a "render in LuxCoreUI" button.

I guess it's correct then, it's a rather contrasted test scene so I can understand that it takes some time to render to acceptable noise levels.
Thanks for your help!
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blender_2018-01-25_22-54-45.png
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Dade
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Re: Very noisy renders

Post by Dade »

chafouin wrote: Thu Jan 25, 2018 9:55 pm It's sad that Blender seems to be slower than LuxCoreUI, maybe it would be good to have a "render in LuxCoreUI" button.
It may be only a problem of increasing the time between screen refreshes in Blender (a screen refresh in Blender is more heavy than in LuxCoreUI), there is a control in Blender for that.

P.S. out of curiosity, can someone render this scene with Cycles with similar parameters (max. path depths, materials, light sources, etc.) ? To have a (vague) idea of a comparison.
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chafouin
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Re: Very noisy renders

Post by chafouin »

Dade wrote: Thu Jan 25, 2018 10:39 pm It may be only a problem of increasing the time between screen refreshes in Blender (a screen refresh in Blender is more heavy than in LuxCoreUI), there is a control in Blender for that.
Lowest refresh interval is set to 5 seconds in blender.
Dade wrote: Thu Jan 25, 2018 10:39 pm P.S. out of curiosity, can someone render this scene with Cycles with similar parameters (max. path depths, materials, light sources, etc.) ? To have a (vague) idea of a comparison.
I'm on it!
chafouin
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Re: Very noisy renders

Post by chafouin »

So I think there is something interesting with Cycles. First samples refine the image much quicker than LuxRender, but then it seems that it always really struggles to render an noiseless image. I have had the same feeling when comparing Cycles with Radeon ProRender.

Here is a render using principled shaders, reflective and refractive caustics. It took 173 secs for 400 samples using the GPU (512 tile).
In the end, LuxCoreUi is slightly faster (166 sec) and also ends up with less grain, especially in the glass caustics. I know I haven't pushed the Cycles materials to match 100%, but Lux materials are pretty realistic out of the box :)

Also made a comparison with another 2.79 build GPU+CPU (32 tile): 131 seconds. But if I add samples to come closer to 166 seconds, the difference in grain is almost unnoticeable.

I am attaching the scene with the Cycles materials.

I will test tomorrow to add back the metallic ground and see who wins with the glossy reflections.
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test_luxcore02.blend
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kintuX
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Re: Very noisy renders

Post by kintuX »

B.Y.O.B. wrote: Thu Jan 25, 2018 9:24 pm Hm, or maybe it disables direct light sampling, too?
kintuX wrote: Thu Jan 25, 2018 9:14 pm @Dade
Will all Pixel Filters be added and exposed as they used to be?
I had the feeling that the default (BLACKMANHARRIS) is already the best setting and you never want to change it.
The only exception being the NONE filter, which improves speed on GPUs and is supported.
:oops: Sorry, :( but i am honestly disappointed.

I like & love to use all three filters depending on the task (gaussan = soft, mitchel = sharp, B-H = middleman). These made such a huge impact on my vision, redefining the noise. That i got used to make digital film grain. I can tell you from experience i rather render 10-30 minutes more then use any denoiser and then bringing a touch of the grain/noise back... wasting a bit more time.

Majority doesn't like 'fake plastic dreams'. And often times, having the ability to control filtering helps in cases similar to the topic. The god & the devil are in details. No other engine comes close in this regard (but now...). I'm getting such a bad taste with all the glazing skimmed off the pastry DeLuxe... as it gets mixed with fast food.

So pretty please, keep the soul alive & my sincere apology for the byte off... ;)
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B.Y.O.B.
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Re: Very noisy renders

Post by B.Y.O.B. »

No problem, then I'll add support for the filter type.
We are in alpha testing phase and need user opinions to create good software.
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Dade
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Re: Very noisy renders

Post by Dade »

B.Y.O.B. wrote: Sat Jan 27, 2018 1:51 am No problem, then I'll add support for the filter type.
We are in alpha testing phase and need user opinions to create good software.
May be, we can add a "Advanced settings" button to optionally show the complete pixel filter settings "on demand :?:
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kintuX
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Re: Very noisy renders

Post by kintuX »

Thank you, thank you very much!
That would be great! :D
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B.Y.O.B.
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Re: Very noisy renders

Post by B.Y.O.B. »

Added support for these filters (note that Mitchell is MITCHELL_SS behind the scenes).
I don't think anyone will ever want to use a box filter - is that correct?
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chafouin
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Re: Very noisy renders

Post by chafouin »

Nice addition!

B.Y.O.B., is there any reason why the film refresh has a minimum of 5 sec? I can imagine that refreshing every 5ms can slow down the render, but LuxCoreUI at 5ms is faster than a render inside Blender at 5 seconds.
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