Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: gabyanz on 2015-12-07, 12:30:56

Title: What is the best way to light a scene with strong artifical lights, in corona?
Post by: gabyanz on 2015-12-07, 12:30:56

I was just wondering... (I don't know if it's the right part of the forum to post this)

I work very often with shops that have a very strong artificial lighting and a weak natural light from the exterior.

(I've attached some photo examples)

In vray, I've always light this kind of scene with rectangular lights and very few IES. The bigger the rectangular light were, less noise they would produce... but the results were very flat and very slow if working with lots of ies lights.

In corona, I've tried different approaches, but I still fell that I've not foud the best "balance" (time/noise). Lighting only with IES lights seems very slow and noisy (I've not tested the new release strongly, although),
 Using only rectangular lights gives a flat lighting, but using the single lights as light emitter (with corona light material) is an headache ... lots of noise and deadly slow...

What would be your approach? Am I doing something wrong?

thanks
Gaby

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: maru on 2015-12-07, 16:55:26

Hi, I would just use IES lights. They should render reasonably fast. I am attaching an example. This is a simple scene and the setup was quick and dirty, but it doesn't look like there are any problems. The main goal is to avoid any kinds of mistakes that could increase noise - like lights intersecting with objects, lights shining directly at highly reflective objects (though I added reflectivity to all walls and floor to make it harder), too high albedo.
~15 min rendering, there is still some noise, but not much, and it would probably require better render settings.
The "filaments" in halogens have Corona mtl with self illumination. They would cause problems if they were lights, but self illumination gets clamped by MSI so there is virtually no problem with caustics. I think if you populated the scene with some high-poly models the render times would be still reasonable.

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: Noah45 on 2015-12-08, 06:14:42

Combo lighting . It's always good to see someone rendering for tomorrow/today (retail) .

Accurately depict your ambient, but more important sell the idea!, through composition

Or in retail, we dress that pig..."Real nice" :-)

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: gabyanz on 2015-12-09, 11:58:51

Thanks a lot, Maru.

I see that you used the self illumination slot... I use the light material but "emit light" disabled". What is better?

I have some  max ies light from max ( rigged ) that the converter does not convert, I fear that I will have to replace all this light with Corona IES (I see that the max ies emit less light and noiser...)

@noah45 .. My renderings are always.. for yesterday ;) I know that you understand me ;)

gaby

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: maru on 2015-12-09, 12:12:32

Quote from: gabyanz on 2015-12-09, 11:58:51

I see that you used the self illumination slot... I use the light material but "emit light" disabled". What is better?

The only difference is that the self illumination will actually illuminate the scene, but very dimly (if set to reasonable values). You can go ahead and use light mtl with emit light off.

Quote

I have some  max ies light from max ( rigged ) that the converter does not convert, I fear that I will have to replace all this light with Corona IES (I see that the max ies emit less light and noiser...)

The converter won't convert native Max lights as they are supported by Corona.
They should not render slower than Corona ones. Just make sure they are not inside some glass/other geometry. Actually in some cases the Max IES lights would be faster than Corona ones. Make sure that correct shadows are used (Corona Shadows). 

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: gabyanz on 2015-12-09, 19:51:07

thanks a lot Maru, I'll try to test them better.



I also have to check " area shawdos" , right?

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: maru on 2015-12-10, 12:57:12

Yup. Are shadows if you want them realistic.

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: romullus on 2015-12-10, 13:24:25

Quote from: gabyanz on 2015-12-09, 19:51:07

I also have to check " area shawdos" , right?

No, area shadows are not supported. Use Corona shadows or no shadows at all.

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: maru on 2015-12-10, 13:36:02

I think (hope!) he meant this.

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: romullus on 2015-12-10, 13:42:53

Ups, never noticed this rollout... maybe it's because i never used photometrics in Corona :]

Title: Re: What is the best way to light a scene with strong artifical lights, in corona?
Post by: gabyanz on 2015-12-10, 18:14:21

Yes, I was talking of these area shadows :)

thanks