Wet surface

Does anybody have informations, Links or Tutorials about “wet surfaces”. When a liquid touches a surface it changes the apperence of the material dramaticaly. It becomes darker and more reflective. I never saw anybody making experiments on this field in Blender.

do you want the whole surfact to be wet, or part of it? For part of it, run a fluid sim, using a material with an alpha value <1 as you are indicating so you can see the floor or table beneath it. Many fluids though are opaque, like coffee.

I didnt explain my idea very detailed- sorry for that. Im not talking about fluids in the sense of Blender. Blender fluids dontt change the surface, they dont interact. But in reality a surface gets wet and this has enormous concequences.
One is the change of colour and refraction. In the picture belove I tried to reproduce the effekt of wetness on wood. The colour of wet wood not only gets darker, but also the color changes in comparison to the original. Wood for instant becomes a little bit more green/blue. The diffusion encreases and the refraction decreases.

My problem is the effect of wet stones or wet asphalt. Look at a street after a rainfall. I see what is happenig. The colours get darker and the surface refracts the colour of the sky like a mirror. This happens because water creates a small film on top of the stones and acts like a mirror. But unfortunatly I´m not able to reproduce this effekt in Blender. I searched this forum but didn`t find any picture or explanation concerning this theme.

http://uploader.polorix.net//files/30/tropfende_Vase_jpg.jpg

Perhaps you could use RayMir and paint a mask to limit it to wet areas. That would make it reflect.

I have found a tutorial concerning this theme for Max3d, but I still have difficulties to reproduce these effekts and materials in Blender.

http://www.neilblevins.com/cg_education/wet_materials/wet_materials.htm

http://uploader.polorix.net//files/30/Dennis%20Stock%20-%20James%20Dean%20.jpg

http://uploader.polorix.net//files/30/feldweg%20.jpg