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Sun lighting

Posted: Sun Mar 18, 2007 7:32 am
by scandog
Hi,

I have created a simple scene and I am trying to light it with just one sun light in blender.

It doesn't seem to work. The inside of the room is very dark. I looked at the xml file and it didn't show sky for the lighting. I changed the settings on the export to SunSky, and it still doesn't seem to help.

I was trying to go by the blender indigo tutorial with suzanne on a box. That seemed to work okay but I couldn't get any shadows.

I am using indigo_06 with bender export .6beta3
Network rendering to 3 dual core computers.

Can anyone help.

Thanks

Posted: Sun Mar 18, 2007 7:45 am
by Kram1032
If it's exactly midday (the sun is exactly pointing down) it should look like this, I'd say ;)
Try to lower the angle, so that the sun also comes a bit forward through the windows! This should help ;)

Posted: Sun Mar 18, 2007 8:16 am
by scandog
I have the sun at a 30 degrees pointing right in the windows. I have tried moving it up and down and changing the angle but its like its ignoring the sun altogether.

I just created a half sphear and made it emit light with a value of 1 in blender. Then switch to background in the indigo exporter. The mesh light seems to brighten up the room but now the out side is black.

Posted: Sun Mar 18, 2007 8:37 am
by Kram1032
What's in the outside? I don't think, that there is anything... -> Bg-Lightning with values 000 is black -> nothing can be lit outside -> result is clear ;)

Posted: Sun Mar 18, 2007 11:17 am
by neepneep
Try linear tonemapping @ 0.004 or so.

Posted: Sun Mar 18, 2007 11:34 am
by manitwo
Image

if you look at those shadows you'll see that the sunlight comes from the right. maybe the sunrays misses all objects.
readjust the direction of your sun.
do you use glas-windows?

just in case you don't know - you could (if you fail to manage this using other methods) combine two images in photoshop in screen-blendmode:

Image

Posted: Sun Mar 18, 2007 2:24 pm
by scandog
Thanks for the help.

I have adjusted the sun abit and have managed to get some light in the room. It still seems quite dark.

I will post another render once I leave it for a while.

That might be a good idea to combine the images but I would like to get it to work. I have seen some amazing images using just one sun light.

What about materials. I am just using difused materials. Are there any tricks to materials in indigo? I am really struggling to find any good tutorials.

Posted: Sun Mar 18, 2007 10:41 pm
by Kram1032
this brownish glass is diffuse, too?
I don't think so... It looks like phong...

Posted: Sun Mar 18, 2007 11:46 pm
by manitwo
to make the interior brighter:
- use "violet" (indigo tonemapper) - u have to use 0.7t5 and set "save_igi" in the inifile.txt to "true"
or
- higher the values of your tonemapping settings.

a good tip for your materials: dont use pure white diffuse materials - this would result in higher rendertimes and unrealistic white materials (a realistic value for pure white paper is 218,218,218(rgb)).

Posted: Mon Mar 19, 2007 3:52 am
by scandog
Yes the cup is phong, All the rest are diffuse.

I have rendered another image. I changed the wall color to white from light brown. I also changed the burn value to .5 with reinhard. I have tried linear with .004 but that didn't seem to help.

I have uped the value of turbidity but that doesn't seem to change anything.

Posted: Mon Mar 19, 2007 4:00 am
by Kram1032
218 ^= 0,8515625 ;)

Posted: Sat Mar 24, 2007 3:09 am
by Aethereal
I have only a little doubt: there is a wall behind the camera? I can't tell from your scene description.
If not, the light coming from the outside will simply be lost and won't be reflected to illuminate the table, the glass and the walls from the camera side.
You'll have to work on the tonemapping too, of course, because sunlight is very bright.
You'll get the same result with a real camera when the subject is between you and the sun (and that's indigo power, strict adherence to physics laws)

Posted: Sat Mar 24, 2007 6:09 am
by Kram1032
ah, yes, that seemsto be a soluton :D
A part of the reflection inside the cub appears black :D