Managing with many lights in corona

[fobus]

   I'm trying to investigate the truth with huge amount of lights in Corona renderer.

   Testing different scenes with Corona reveals some of strong sides of it along with the weakneses of course. Some of weakneses was our faults, but some of them are not.
In testing of night scenes I was found that increasing the lights amount has downside in increasing the noise amount. It may be normal, but time needed to remove this noise is terrible. In some cases it is few hours and  tens hours and even more (http://forum.corona-renderer.com/index.php/topic,2268.msg16956.html#new). But I found that some people managed huge amount of lights with no problem at all (http://forum.corona-renderer.com/index.php/topic,1487.0.html).

   In this case I started to investigate the problem in very simple scene with plane and 2500 light sources. With no GI at all. At default settings and 50 passes (to have nice DoF if needed) the noise is completely terrible in 11 seconds.
   The next step is increased Light Samples Multiplier from 2 to 100 (max settings). This variant is noisy and waaaay too long to render - 7:00 min (if we keep in mind that it is plane with default material with no details at all). But as I know from real scene rendering if we have LSM that high the HD Cache is waaaay too long to compute.
   Changing PT samples to 800 and LSM back to default (2) lead me to same amount of noise and time to render - 7:07, so nothing changed (except that HD Cache will compute much quicker in render with xxGI).
   Well, does it possible at all to render this simple scene with no noise (even if we close our eyes on render times)? Heh. PT-200 and LSM-100 in 55 minutes... Nearly clean but not as Vray in 11 seconds (scene attached).


   So. The main question is it really possible to render scenes with huge amount of lights in acceptable rendertimes? In huge amount of lights I mean not only Corona lights and dedicated light sources with emission, but even one plane with checker texture that creates huge amount of virtual lights. I ask all to particiate in testing of this scene to fing the truth!

[rafpug]

Hello fobus

Have you tried to use 2500 source emitter, to see the behavior of light with the noise?

[fobus]

Hmm... I can't get Corona to understood the texture with 2500 light samples. It is simply too much of them and too small each of them on texture to render the light from each other separately. If You could render my scene with setup You describe I'll be appreciated.

[Polymax]

This is not a correct comparison, because completely different sampling algorithms.
Issedovaniya need to spend on complex scenes, for a full understanding.
And I'll say exactly what raytrace in Vray a lot slower than in the corona.

If you put an object in this scene and enable GI with LightCache - Vray will die. Or BF as secondary with 25 bounces ;)

No solutions in Corona for this case (IMHO).

for lighting with small texture use texture resolution (default=0.3). you need set to 1 or more. (but I've tried this method and got the same result like with separate light sources)

Note: Corona not working without GI. Even if you set primary solver to "none"

[fobus]

This is not a correct comparison

There is no comparison at all. I just want to render clean direct light from many lights in Corona. I found it is impossible at the moment. This scene is made just to find a way to render direct light clean. If You have any tips how to render it clean please give us an idea. VRay here just for understanding what I mean clean and quick.

[Polymax]

This is not a correct comparison

There is no comparison at all. I just want to render clean direct light from many lights in Corona. I found it is impossible at the moment. This scene is made just to find a way to render direct light clean. If You have any tips how to render it clean please give us an idea. VRay here just for understanding what I mean clean and quick.

I already answered that, within 1 minute - no solutions. (in this case)

[maru]

If you really want to render with no GI, set "max ray depth" to 1.
update: at least I think so, and it seems it has no impact on render time here :)
update: or maybe it has, I'm confused

[fobus]

If you really want to render with no GI, set "max ray depth" to 1.
update: at least I think so, and it seems it has no impact on render time here :)

Ok. This image with no GI as Max Ray Depth was set to 1. But it is really no impact on render time in this case. What I need is clean direct light. Not only in this scene. If you check links in my first post you can find out why I really want to find out a way to clean direct light. And not only this scene needs to render quickly. I'm doing night scene with many small lights now and ther is no way to get clean image with corona in accepable render times just because of this NOISY DIRECT LIGHT.

Polymax in test with 165,000 light sources was able to get clean image and I think we're all interested how it was possible.

May be someone can test my scene with many lights and will find any errors in scene setup to point me the problem.


I think that rendering average scene with high amount of lights must be not such big problem with Corona, but I can't get it right. HELP please.

[rafpug]

Hello fobus

I'm trying to understand this your example
work in progress

[fobus]

Hello fobus

I'm trying to understand this your example
work in progress

Thank You for your try. If You want to see real example use this link http://forum.corona-renderer.com/index.php/topic,2250.msg16927.html#msg16927

[maru]

Here is my try on my i3. Had to modify some stuff because of version difference. This is after 10 minutes. What is your goal time?

[fobus]

Here is my try on my i3. Had to modify some stuff because of version difference. This is after 10 minutes. What is your goal time?

Goal time? I think it is 11 sec as Vray do. But I think it is impossible to have clean picture in that amount of time. Can You tell us what settings You have changed to archive this result?

[rafpug]

Hello fobus & maru

here my test!

[fobus]

Hello fobus & maru

here my test!

Noise and render times is ok, but I see no 2500 particular lights. Looks like some fluctuated light sources randomly placed in the scene.

[rafpug]

Another test

09sec.