Radiosyte definitions !

[jono338]

Hi people,

new here ... just looking at C4D ... looking good so far.

Radiosity, from what I understand, is a way of modelling how light actually works in a scene, like ray-tracing, but with radiosity, when light hits a surface, that surface can then be considered as light source for the scene, as it reflects light back. What sort of light source depends on how the surface interacts with the light that hits it.

Thats the *really* simple explaination ... for complications ... consider that each surface has to be broken down into small bits because light might be hitting different parts of it in different ways, then each of those small bits becomes a light source. Pretty soon you've got a truck load of computing to do.

Cheers,
Jono

[mt_sabao]

Yeah, that´s about it. In the physical world, when a photon hits a surface, its re-emited back, or else things would start to heat up (that´s why a black t-shirt is hotter than a white one, the black re-emitts only a small percentage of the light hitting it).
The photon hits an electron of the atom that constitutes the surface, excites it, and then the electron goes back to an unexcited state and emits another photon, with diferent caracteristics, mainly, its wavelenght. This is what defines the color of the surface.
Radiosity simulates that. Like jono said, every surface is a potencial source of light, depending on its caracteristics:reflection, specular etc.

Homework:
Do a simple experiment. Stand in a dark room with just a small desklamp. Place some sheets of diferent colors in the desktop where the lamp is illuminating. Watch what happens to the lighning in the room.

[flingster]

there is a really good tut here for radiosity in cinema

http://mvpny.com/RadTutMV/RadiosityTut1MV.html

but it is also worth reading the manuals definition cos i think it explains it really well...imho

[loki1_11]

Yah that was what I was thinking to :)


I made some test's before post this tread here for example
I had made an sphere and put an metal texture and put it to render with radiosity activated
so after that I had picked up an metal ball that I had in my desk and turned of the light, set my litle spot ligh turned to the metal ball and I saw how much it was equal my cene ...
the result's of ths test was amazing ;)

So I recomend to everbody do that to see how it exactly works !!


Cya :)

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