Strange VrayLights behaviour

[3LP]

Hi all,
I'm currently being working on the lighting part of a internal dome pool.

Since the beginning I have some stranges problems with the way the light behave.
I have modeled all my model in real world scale and here is a exemple of what I have done so far.




But I have a big problem, the light doesn't spread as far as would like.
I have tried all my hard to do it work with vraylight (because I really like them) but couldn't be able to achief what I wanted.
So I have tried to do it with normal standard light and that some close look of what "spread light" I would like to have.



But I have really some big issues with thoses lights.
Green lines for render problems, some leaks of lights, don't understand why.
I used the universal rendering parameters for this image and the lightcache is just not cool. Even at 3000 (like this images above). With Brute force as second bounce I have no more problem but say hello to rendertime.

Red lines show the way I have to put my standard light to have something somehow good for the center of the image, but doesn't go when you see it from the side.







Now, The real problem :

(that's the render with only 1 light slide)




How does it come that the light spread like that, and, how can I do that the light spread more like the standard light with the Vraylights ?

I think I have a cool image (on the top) with vraylights but have to get the light spread much more... (client ask).

And I'm already rendering with the gama to 2,2 ... ! (With the wonderful script of lastpixel.)

I'm really stuck and I would like to have another point of view.

I can give a slight part of the max if need.

Thanks in advance,

Stan
3LP Team

[vlado]

What are your GI settings?

Best regards,
Vlado

[3LP]

Here they are.

Thanks !

[vlado]

You can try turning off the "Store direct light" option for the light cache and see if it makes things better.

Best regards
Vlado

[3LP]

allready tried that and it doesn't changed anything.

will post you a picture tomorow and a slight part of the scene on your mail.

Thanks!

Stan

[stevesideas]

Theres quite a few things to try. The shadow errors could be something to do with shadow bias settings and possible the vray area shadow size. You may want to try upping the size a bit.

Do your meshes all have depth and are closed ?? That may cause light leaks if not.

The light spread could be increased by increasing the general light in the room and lowering your texture map gamma. You may need to color correct it as the saturation will probably be too intense.

Other than that, I would try using a vraylight material assigned to a strip down those edges where your current lights are. Your lights arent really producing any hard shadows on anything so gi shadows would work nicely. You could always create some area lights that were invisible to brighten up the interior also. Making sure of course you lowered your texture gamma.

[3LP]

Hi steve,
thanks for your comments.

I do have my geometry that's closed, but don't realy understand your way to change the light effect within the texture.
Here is a small part of my scene with the textures that are bring to 512x512 to have only the color info.

If someone has a idea to have the type of light of the standard light with vray light.

http://rapidshare.com/files/18245113...Light.zip.html


Thanks a lot
Stan

[rmejia]

Try changing the VRayLight property to "No Decay" with a multiplier of 0.2 and it will reach out farther.

[stevesideas]

I do have my geometry that's closed, but don't realy understand your way to change the light effect within the texture.

Actually I think I may have it wrong. That light isnt GI light, its direct light...sorry. I was just saying though that I change the gamma of the bitmap texture to something like 1.8 so that the light travels further...it might be worth a try..heh..if only I knew what I was talking about

[3LP]

Try changing the VRayLight property to "No Decay" with a multiplier of 0.2 and it will reach out farther.

woaw, that helped me a lot !
thanks.
but Is there a way to have the possibility to say, decay at 0.5 or 0.7 and not only on/off ?

if not, I will have to use my standard light that aren't good on the sides but, I will not have other choices to tweak my lighting and have it behave like I want to.
isn't it ?

on the left, Vray light with decay because without the light "fly" to far.
On the right Standard light but mess on the side because of the nature of the light (am I right) ?



beside the render artifacts, standard light give the chose to fade light more smoothly, is there a way to achieve that with vraylight? some parameters that I don't know about ?
Vlado ?