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Advanced illumination: How?

Posted: Thu Aug 18, 2005 6:40 pm
by Myth
Ok, so I read this tutorial on gamedev.net... and am not really sure how I would do this. Not at all.
I found it here: http://www.gamedev.net/reference/articl ... cle918.asp

Overall it sais:
1. render cube view from object origin.

2. blur cube view so that all pixels contribute their color equally to the half of the cube view closest to them.

3. use normal mapping to acquire UV coordinates for each vertex of the mesh.

4. texture map the cube view onto the object, except DO NOT USE PIXEL COLORS AS YOU WOULD NORMALLY, instead, use the pixel colors as lighting values, and add those light values to the light already present on the object from traditional lighting methods.

5. Render the scene with it's new light values.
How are you guys thinking about this?
Did anyone ever consider implenting illumination into irrlicht?
Worked out?
And don't think that I'm another newb excepting to create something that is of high quality. I'm just asking, not begging, not expecting.. :)

- Myth

Posted: Thu Aug 18, 2005 9:15 pm
by Murphy
Offhand, I don't think this article actually describes a workable method to get realtime radiosity for an entire scene. Maybe improved lightingg for an object, but with the loss of directionality (though it should be possible to do it somewhat differently and keep directionality).

Among other things, it suggests rendering a complete cube for each object. Even if you do it at low resolution, that's a whole lot more rendering. Realtime quickly goes out the window.

And as far as being radiosity... if you want the whole scene done this way, you actually have to do it over and over because the objects then become emitters and other objects have to be given the chance to re-emit that light, and this goes back and forth basically forever or until you get bored.

Posted: Fri Aug 19, 2005 1:40 pm
by Myth
Ah ok... And there isn't a way just to set glossiness of an object? Without rewriting the whole render part of irrlicht.
The main thing I actually want, is volemetric lightning.
This is possible with a transparant cone somehow...
Here's a render I made in 3dsmax showing what I mean:
nvm the poor scene.
Image

Thank you,
- Myth

Posted: Fri Aug 19, 2005 8:26 pm
by omaremad
the simplest way (like splintercell) is to fake it :D

it is very easy just use a cube in the shape of the light BUT inverse the normals so only the very last faces forming the light appear

of course us transparency

Image

Posted: Sat Aug 20, 2005 12:51 pm
by Myth
Ah thanks. But how to inverse normals?
Do you mean normal texture maps :?:
And I tried this method, it worked good (but looked bad), I just made a normal cone with white texture on it and then transparant... looks bad, I proberly have to flip normals somehow...

Thanks,
- Myth

Posted: Sat Aug 20, 2005 1:12 pm
by omaremad
sorry i used the wrong term

model it in a program and export


add it into irrlicht then do this func

mesg manipulator then flipSurfaces(IMesh* mesh)


add transparency and texture to add color to it

Posted: Sat Aug 20, 2005 5:33 pm
by Dances
I'm not the one asking the first question, but... is there a way to have a haze around that light coming through like a light should? Could that be done with foggy particle effects or something?

Posted: Sun Aug 21, 2005 11:39 am
by Myth
I am going to try that effect with adding render to texture to the light mesh.
So I render an animated particle effect to the light texture (for distorsion).
And also I will add a particle effect inside the light mesh(for dust).