metropolis CPUvsOpencl

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lacilaci
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Re: metropolis CPUvsOpencl

Post by lacilaci »

Sharlybg wrote: Sat Oct 27, 2018 3:18 pm
It may be possible but it could mess (a LOT) the MIS so I'm not sure if the outcome would work.
I think all the frustration around all that biased vs unbiased and tricky features request will mostly be cooled down by LC2 (indirect light acceleration feature). I'm myself facing all the same limitation each time i work on a new project ( mostly interior archviz) , it's so hard to wait and work on path tracing for indirect dominant 3D scene now that we know LC2 is planned.
I'm myself working currently on a very serious interior project all Image have to be rendered in 2k (The printer ask for 4K but can't afford this). Compared to old Lux 1.X series it is day and night ( impressive speed and quality at the same time ;) ) adaptive sampling and Visibility map feature help a lot ( Thank Dade and BYOB for that).

Lacilaci i can really understand you sometimes i wake up by night on my bed and just wonder how beautifull thing could be if LC2 was already implemented inside the engine. My heart and my brain are litterally screaming for this feature all the time ( WTF 4X to 8X speed up in interior rendering compared to current already good version is total insanity). The first opensource renderer to support LC2 even on GPUs (opencl) This is terrorism Dade should go to the jail for only mentionning this feature :lol: .

This is my confession even if i can look super self controlled sometimes i'm completely burning inside while waiting for this to happen :lol:

Now i'm Out :arrow:
I agree about the lightcaching, but variance clamping can help a lot too if you don't need to worry about direct lights and it's reflections fading away cause of low clamping values.
Right now you need to find balance so that you can use low values but don't loose contrast, if you could keep strong contrast of direct light contribution and its reflections you can in theory use lower clamping values that speed up rendering and only remove contrast of indirect lighting, which can be still ok in many cases.

But if it should break something or make the tool complicated to use then yes, rather keep it the way it is.

The reason I keep coming back to this issue is that at first I thought it's only problem with sun light, cause it's a strong light source etc... But I see the same thing in night scene with area lights, where I'm ok with low clamping values for everything except direct light. Because it becomes darker on walls it directly affects and those become dark in reflections, overal scene suddenly looks weird.

EDIT: Also, in terms of performance let's not forget denoiser.
It is one thing that it is "a final frame denoiser" doing what it says it do. Removing residual noise from near final rendering.

But here is the thing about performance. If the denoiser is slow and borderline useless in previews, it cannot be used for anything else than final rendering. I think we can all agree that it is nowhere near usable for previews.
without denoiser this means that to get an overall feel of how my lighting and scene color composition looks I have to render quite a few samples. And it makes testrenders painfully slow. So even if I find luxcore incredibly fast and really want to use it whenever I can, I cannot exclude this fact from performance, my performance goes down if I need to endlessly wait for testrenders.
Cycles's denoiser can quickly bring out details and smooth lighting in a completely useless render in terms of noise. But even though it would not be a good final render, I am able with 2-3 minutes render 4K complex interior and see exactly what is going on with lighting and textures and composition. This is priceless, you can always push slow rendering on renderfarm, but you cannot use renderfarm on daily previews.
This is why I always bring up the nvidia denoiser, with a proper integration it can effortlessly in an instant show you what is going on and you always know what you are doing and it is a solution that is right there waiting to get implemented.

Currently as my scene grew complex and I see that I'm waiting 20min. and I'm still not sure If I will like it I'm in stress, and this is a personal project. I already had a smaller project that I know would be faster in final rendering on luxcore but I would be slower a lot and in a lot of stress with tons of re-rendering just to see that this light is no too good, or this reflection I don't like etc. So I used cycles, not because it would be better or faster but I could have 1-2 min. previews that show everything in detail..
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Sharlybg
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Re: metropolis CPUvsOpencl

Post by Sharlybg »

I agree about the lightcaching, but variance clamping can help a lot too if you don't need to worry about direct lights and it's reflections fading away cause of low clamping values.
Right now you need to find balance so that you can use low values but don't loose contrast, if you could keep strong contrast of direct light contribution and its reflections you can in theory use lower clamping values that speed up rendering and only remove contrast of indirect lighting, which can be still ok in many cases.

But if it should break something or make the tool complicated to use then yes, rather keep it the way it is.
I agree wit you. About denoiser i'm now using Darktable When the image is final render and around 2K or more.
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