[SOLVED] Another Rooky question

[michael.stamm]

Hi,

 

Say, I wanted to have a really simple room, more or less naturally lit. The room is a cube,10x10x10m, with one window, perhaps 2x2m, in the middle of one of the cube´s sides and a matt white material on every wall.

 

I would like at least the following two effects to happen:

 

1. If the sunlight shines through the window, I would expect the whole room to be lit in the suns color and not only the shape of the window projected onto the wall.

 

2. If the sun dosen´t shine through the window, I´d like to have the rooms walls across the window lit in a subtle blueish color from the sky.

 

How can I achiev that? Do I have to use certain material settings? certain render settings, or sunlight settings? Or a combination of all? I can´t imagine that I would have to fake that with manually set omi lights or sth.

 

 

Thanks in advance!

[ulf.schroeter]

You should dig a little bit deeper into global illumination, e.g. http://en.m.wikipedia.org/wiki/Global_illumination . Real-world lighting based on multi-bounce reflection is a little bit more complicate than one might think

[michael.stamm]

Thanks for the reply.

That means, I am asking to much? Or is there just no simple answer?

[ulf.schroeter]

That means, I am asking to much? Or is there just no simple answer?

Well, I would say you just picked the hardest part of realistic 3D computer graphics lighting: indoor scenario with light only entering through a window (which means most of the room is not directly lighted as it is the case in outdoor scenarios, but only by multi-bounce light reflection).

 

This lighting is still hard to achieve in real-time. Due to the complexity of realistic lighting this has to be done most of the time in a modelling tool like 3DMax or Maja with the help of Radiosity non-real-time rendering (see this page for an introduction). These tools can than be used to export so-called lightmaps, which can be rendered in real-time together with other dynamic light sources (spot lights, omni lights).

 

UNIGINE also offers an in-engine off-line approach for baking complex lighting from multiple UNIGINE lights into lightmaps, so the whole scene can then be rendered in real-time. See this blog for an introduction and read the UNIGINE editir documentation. But nevertheless complex lighting is still a fake in 3D real-time graphics today.

[michael.stamm]

Thank you for the link and for your explainations. I´ll take a look at those lightprobs...

[manguste]

Actuyally, for a start you can try to add a simple environment texture to modulate environment lighting. It's grabbed in one button click, yet it drastically improves the picture

[michael.stamm]

Thank you for your tip manguste. In the meantime we tried out environment textures and lightprobes and found lightprobes to deliver the more satisfying results in our indoor scene.

[manguste]

Glad to hear that, they definitely give more accurate results in such cases :)