LuxCoreRender Forums

To decide we should make a real production interior scene and compare Luxcore against some of the spectral renderer out there. we should clearly answer to thoses question.

What do we miss in full spectral rendering ?

Is only corner cases effects only features ?

Do the difference is that huge most of the time ?


BTW i always wonder what make real photo lighting/shading interaction so real compared to even high quality render by pro like Bertrand benoit or even NMachine (Nmachine being a monster for me but reality lighting and shading behaviour beat him somehow ).

Is it spectral ?

is it tonemapping ?

is it light bounce ?

lacilaci wrote: ↑Wed Jan 22, 2020 12:55 pm Also Dade, you said dispersion is pointless for pathtracers but how do you do diamonds, and some thin film dispersion effects.. All spectral renderers can do those effects, yes they might not be able to do caustics but rest looks correct and there is no easy "fake" to do dispersion. There are some fakes but look like dogshit.

Dispersion is, by definition, a caustic. Most renders supporting spectral rendering do light tracing too (Old Lux, Maxwell and Indigo).

In my opinion it could be useful just for corner cases and as Sharlybg said there are beautiful images without any spectral mode involved.

My thought about this kind of "superRealModes" is that if they're free in terms of rendertime ok.. nice... but if I have to render an interior with double of the time with more or less the same result of the non spectral... no way.

From my point of view, it's more important to have fast preview and fast and flexible render elements system. This will give you the opportunity to make small final tweaks quickly and add that kind of quality that make the difference from a "normal render" to a "masterpiece".

Sharlybg wrote: ↑Wed Jan 22, 2020 1:05 pm Btw Radeon prorender is doing spectral rendering on viewport with vulkan : http://www.cgchannel.com/2019/12/radeon ... rendering/

I think they are using the word "spectrum" with the meaning "a wide range of techniques" here, since they are talking about a transition from rasterized -> hybrid -> biased -> path traced.

Dade wrote: ↑Wed Jan 22, 2020 1:39 pm

lacilaci wrote: ↑Wed Jan 22, 2020 12:55 pm Also Dade, you said dispersion is pointless for pathtracers but how do you do diamonds, and some thin film dispersion effects.. All spectral renderers can do those effects, yes they might not be able to do caustics but rest looks correct and there is no easy "fake" to do dispersion. There are some fakes but look like dogshit.

Dispersion is, by definition, a caustic. Most renders supporting spectral rendering do light tracing too (Old Lux, Maxwell and Indigo).

Ok Dade you know your stuff, I'm not even able to argue.
But octane, fstorm, old fryrender or arion could do those effects and claimed spectral rendering while not really capable of any caustics.

I also got my hands on spectral cycles build now and it does make difference even in basic scene setups when it comes to color and light distribution. Although I don't know yet which is the correct result lol ... early build probably has some issues so the difference might be less noticeable in the end.

B.Y.O.B. wrote: ↑Wed Jan 22, 2020 1:52 pm

Sharlybg wrote: ↑Wed Jan 22, 2020 1:05 pm Btw Radeon prorender is doing spectral rendering on viewport with vulkan : http://www.cgchannel.com/2019/12/radeon ... rendering/

I think they are using the word "spectrum" with the meaning "a wide range of techniques" here, since they are talking about a transition from rasterized -> hybrid -> biased -> path traced.

My bad they fooled me.

In my opinion it could be useful just for corner cases and as Sharlybg said there are beautiful images without any spectral mode involved.

My thought about this kind of "superRealModes" is that is they're free in terms of rendertime ok.. nice..if I have to render an interior with double of the time with more or less the same result of the non spectral... no way.

From my point of view, it's more important to have fast preview and fast and flexible render elements system. This will give you the opportunity to make small final tweaks quickly and add that kind of quality that make the difference from a "normal render" to a "masterpiece".

It quite a long time since Lux isn't full spectral. and there is no real great comparison arround the Web. So i think we should definetly test and make good conclusion.

Sharlybg wrote: ↑Wed Jan 22, 2020 1:59 pm

B.Y.O.B. wrote: ↑Wed Jan 22, 2020 1:52 pm

Sharlybg wrote: ↑Wed Jan 22, 2020 1:05 pm Btw Radeon prorender is doing spectral rendering on viewport with vulkan : http://www.cgchannel.com/2019/12/radeon ... rendering/

I think they are using the word "spectrum" with the meaning "a wide range of techniques" here, since they are talking about a transition from rasterized -> hybrid -> biased -> path traced.

My bad they fooled me.

In my opinion it could be useful just for corner cases and as Sharlybg said there are beautiful images without any spectral mode involved.

My thought about this kind of "superRealModes" is that is they're free in terms of rendertime ok.. nice..if I have to render an interior with double of the time with more or less the same result of the non spectral... no way.

From my point of view, it's more important to have fast preview and fast and flexible render elements system. This will give you the opportunity to make small final tweaks quickly and add that kind of quality that make the difference from a "normal render" to a "masterpiece".

It quite a long time since Lux isn't full spectral. and there is no real great comparison arround the Web. So i think we should definetly test and make good conclusion.

well, maybe cycles can help with this. We'll see if it gives any improvements on cycles and see if it's worth it in production...

Here's latest Octane for Blender:
Download Octane 2019 for Blender 2.81 RC (free tier) - Updated 2019-11-12

kintuX wrote: ↑Wed Jan 22, 2020 2:38 pm Here's latest Octane for Blender:
Download Octane 2019 for Blender 2.81 RC (free tier) - Updated 2019-11-12

Yes but how do you compare octane vs spectral rendering octane? Is there a switch to turn of spectral rendering in octane?
This new build of cycles allows for pretty much direct head to head comparison to see if it's worth it in some produciton (dispersion effects aside)

Yes but how do you compare octane vs spectral rendering octane? Is there a switch to turn of spectral rendering in octane?
This new build of cycles allows for pretty much direct head to head comparison to see if it's worth it in some produciton (dispersion effects aside)

I feel the blender one a bit young currently. So in mind the target was to compare octane Spectrale to Luxcore.