Hybrid Back/Forward path tracing (aka BiDir without MIS)

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Dade
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Dade » Thu Jun 27, 2019 11:59 am

lacilaci wrote:
Thu Jun 27, 2019 11:27 am
These results are crazy. :shock:
It is the combo light tracing/metropolis sampler, it is just insanely good to render caustic paths. It is like rendering in one sample what usually take 1000.
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by epilectrolytics » Thu Jun 27, 2019 12:12 pm

Dade wrote:
Thu Jun 27, 2019 11:57 am
It is the result of a malformed scene: you have not set the world volume.
Thanks for pointing this out, I had just figured it was a volume issue but couldn't yet nail the missing part.

Glad to see it's no bug and the engine works all right!
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by provisory » Thu Jun 27, 2019 12:36 pm

Dade wrote:
Thu Jun 27, 2019 11:34 am
It is a known limitation, there from day one of laser/laser-like light source support.

Hybrid can now render the light scattered after the mirror bounce (i.e. the caustic path). Light tracing could be used to fill this particular "hole" in normal path tracing too but it is not one of my top priority at the moment.
That's all right.
If someone needs it, just put a glass plane in front of the light with IOR 1.0, and it will be visible immediately (with hybrid OC).
I tried, and it works! :)

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Dade
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Dade » Thu Jun 27, 2019 12:38 pm

I'm going to use this as manifesto:

manifesto.jpg

(aka "if you use something else, you are out of your mind" :lol: )
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Dade » Thu Jun 27, 2019 12:41 pm

Dade wrote:
Thu Jun 27, 2019 12:38 pm
(aka "if you use something else, you are out of your mind" :lol: )
Also: "CPU-only rendering is now officially dead".
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by epilectrolytics » Thu Jun 27, 2019 12:42 pm

Dade wrote:
Thu Jun 27, 2019 11:57 am
It is the result of a malformed scene: you have not set the world volume.
Now I set a world volume but that doesn't help, it's an OpenCL thing:
PathCPU works, world volume or not, PathOCL doesn't work, world volume or not.
I'll prepare a blend file and open a thread in the user support forum.
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Odilkhan Yakubov » Thu Jun 27, 2019 1:37 pm

Dade wrote:
Thu Jun 27, 2019 12:41 pm
Dade wrote:
Thu Jun 27, 2019 12:38 pm
(aka "if you use something else, you are out of your mind" :lol: )
Also: "CPU-only rendering is now officially dead".
Sorry, dont understand exact. Is Cpu doesnt working anymore?
Allah bless us!

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lacilaci
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by lacilaci » Thu Jun 27, 2019 1:58 pm

Odilkhan Yakubov wrote:
Thu Jun 27, 2019 1:37 pm
Dade wrote:
Thu Jun 27, 2019 12:41 pm
Dade wrote:
Thu Jun 27, 2019 12:38 pm
(aka "if you use something else, you are out of your mind" :lol: )
Also: "CPU-only rendering is now officially dead".
Sorry, dont understand exact. Is Cpu doesnt working anymore?
He meant that it is not as good on it's own if you can use lighttracing on cpu and pathtracing on gpu and whatnot...

Buuuut... we still don't have decent out of core functionality so I wouldn't be so sure. Larger exerior archviz (even interior) can easily go over any current gpu vram size. But good out of core and bigger future vrams could help here too.

Other than that. This is fucking awesome :!:

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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Sharlybg » Thu Jun 27, 2019 2:47 pm

Can't just realize what is happening here. good caustic for free only 45 secs for such clean image.

Please never compare Luxcore to Cycles E-cycles or whatever you call it anymore :lol:
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Dade
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Re: Hybrid Back/Forward path tracing (aka BiDir without MIS)

Post by Dade » Thu Jun 27, 2019 2:51 pm

lacilaci wrote:
Thu Jun 27, 2019 1:58 pm
Buuuut... we still don't have decent out of core functionality so I wouldn't be so sure. Larger exerior archviz (even interior) can easily go over any current gpu vram size. But good out of core and bigger future vrams could help here too.
Out of core rendering works with AMD Vega as far as I know (it just works with any application, LuxCore, Cycles, etc. it is just a flag in the AMD control panel). It increase the available ram of about 50% with about the same penalty in term of rendering speed.

Anyway, LuxCore packs about 10,000,000 of triangles for each GB of VRAM so you can render really a lot of triangle even with the current generation of high end GPUs.
High resolution texture maps are likely to be the main problem. An option, it may be worth to explore, could be image compression, it would be a lot faster than out of core rendering :idea:
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