2 replies to this topic

[Psycho_Gamer]

Hello again,

Is there somehow a way to raytrace smoke, such as that from a cigarette? I can only seem to find software packages that do it for you, but nothing useful providing hints on how to do so via good ol c++ :P. Thanks

[Hertta]

Hmm. What about just adding the base color of the smoke (blueish grey?) and then define it's "deepness" from how thick the smoke is or so.

A bit hard to explain, but it should work like that.

[Reedbeta]

Raytracing high-quality smoke, steam, clouds, fire and so forth is done with volumetric scattering. Basically, your scene definition can contain volumes filled with participating media (participating in light transport, that is). When a ray passes through a participating medium, you have to cut the ray into many small intervals and take into account the effects of light absorption/scattering by the medium at each point. It's pretty complicated - if you're interested in learning more, google for 'volumetring scattering' and 'participating media', or I also recommend picking up the book Physically Based Rendering by Pharr and Humphreys, which is the standard text on advanced raytracing techniques.