Lights contrast and GI, need help

[b-spline]

Hi everybody,
I need an urgent help.
I'm trying to light this scene with vray, but the problem is that I need more brightness and contrast
between light and shadows.

I used two identic vray lights, and enviroment lightblue color.
This is vray result:

This is the same corrected in photoshop.

these are scene and settings.

vray lights settings:

GI settings:


If someone could help me, this is max 5 scene file:
http://digilander.libero.it/tafkaandre/temp/scene.zip

[percydaman]

go to your g buffer controls rollout and raise your dark multiplier. I usually start about 1.5 - 1.7 and see how that works. If you save and reuse the irrad map then you can play with the color mapping without recalculating the irrad map. Hope that helps!

[b-spline]

Hi, thank you for the answer,
anyway I think this it technically the same I made with photoshop.
Infact I got the same results.
[url]
May be the problem could be solved with another kind of lighting?

[j.galang]

Vray version 1.09.02Q and up has a new algorithm in the Color Mapping rollout called Exponential Color Mapping, I suggest you give it a try since it is very helpful in lighting interior scenes. Try to play around with the Dark and Bright multipliers with both algorithms and see what suits you the best.


Also as a side note, I think you should upgrade your Vray version to at least 1.09.02U as i think you're not getting your money's worth by sticking to such an old 1.09.01B version. Don't you think so???


JG

[b-spline]

You're right, but I didn't know about these feature.
I think It should be like Logaritmic exposure control in 3dsmax 5.
Anyway, What I want really know is if there is a way to solve di problem
by illumination. May it be a vray light problem?

[j.galang]

i took a quick look at your scene, your ambient value is way too high (in the environment rollout) personally i don't use any ambient light at all, if i do i use very small values (less than 10). and upgrading to the newer versions of VRay "CAN" help you solve the problem (or at least give you more options). If not may i suggest turning off the frame stamp as people might get the "wrong idea" why you insist on working with such an old version of VRay.

JG

[b-spline]

thank you JG.
I think you're right about environment setting, and I have look at new vray features, and of course It will help me upgrading at least to 1.09.02u, I hope to do it tomorrow or in next days.
Anyway, now you know my scene. Can you suggets me a way to get a very good illumination? I need to have a scene with much light (it's barber shop). So, the way to put lights, multipliers, ecc. If you can, you could send me my scene modified.
However, thank you again for your time!

p.s. Turning off frame stamp It's a good idea, at least I'll put just render time

[Psy]

1.09.02u?

why not 1.09.03d at least?

[b-spline]

I wish to know what's the latest commercial version, there are too many numbers and letters, so, anyway...I meant that one

[j.galang]

Sorry b-spline, too busy at work right now, besides if i modify the scene u probably can't use it since I'll probably use 1.09.02U and would probably use Exponential Color mapping to get more light in (this is one of the reasons i suggested an upgrade). try www.vray.info and they have tons of stuff there. you'll learn more by doing things yourself and asking questions.

as for Psy, 1.09.03x are still very buggy for my taste. since i use this software to make a living, its kinda out fo the question for now. also you cannot open scenes saved with the 1.09.03x with earlier vray versions which is a big headache for me. if/when i upgrade from 1.09.02U it will have to be across the board so i'm waiting for a much more stable version to appear and one that will have new features worth upgrading to.

JG

[t1t4]

Not sure this is any better but here is what I came up with without changing much in your scene. The biggest change was selecting "No Decay" in the lights and moving them right into the openings. I also turned on "use interpolation" in the glossy materials to speed things up a little. I am not sure if the version of Vray you are using has that feature or not.

Any way here is the render.


One other thought is to just use a little Photoshop like this.


Here is the file.
http://www.boring3d.com/misc/scene_test01.zip

[b-spline]

thank you t1t4,
your scene is much better about illumination, light is more diffuse, but
contrast problem still continues. I have the sensation like image is out
of focus, shadows are too bright, while the second one is much better, but
increasing contrast in photoshop, there are some areas burn out!



however results are a little better then mine.
thank you too!
I hope someone could help me to get results I wish, in the same time,
I'm upgrading to 1.09.02u

[t1t4]

The bright areas are caused because I checked "no decay" for the lights. It causes the back walls to be much brighter because they are getting more direct light (or light hitting closer to 90 deg to the surface or something like that) than the closer walls.

Probably the only way to avoid this with the vray lights is to use decay but then you don't get as bright a light far away and very bright light right near the light source. I think the thing to do is put some lights or windows in the room to brighten it up. Or maybe use smaller light sources to get sharper shadows and more contrast.

I'm not sure. Maybe I will look at it again tomorrow if I get a chance.

[digitalx3d]

b-spline,
In the render dialog, try reducing your environment multiplier to no more than .5. Also, reduce the secondary bounces from 3 to 2. Bump up your first bounce multiplier between 1-1.5. Then go into the environment dialog and set your ambient color all the way down to black.

You might also want to try swapping out those Vray lights for a single directional light.

This should help.
John Pruden
Digital-X

[b-spline]

Hi John,
thank for your help. I set standard environmento color to 10 and contrast now is much better. Also I used exponential color mapping and increasing each vray light and directional multiplier. So I got this result:

So what do you mean with "set secondary bounces from 3 to 2"?, in my scene is 0.4. and first is 0.9

but now I have another question.
when I use exponential color mapping, my object light (self-illuminated) becames grey!
How can I work out this problem?