realistic crystls - need imput
 

hi everyone. I´m testing materials for creating realistic Crystals now for quite some time. renderer = mentalRay. shaders tested - DGS, diElectric and l_glass. l_glass is the only shader which fakes dispersion, so this is my shader of choice. in addition I applied a glare shader to my renderCam to push the specular highlights.

there are some other criterias but the shader which I am not so experienced in. this is lightning and the usage of background material. I did some tutorials about studio lightning and using DGS material for backdrop and reflector material. but after all it has no other effect than a simple lambert mat. also the lightning stuff. I ended with 13 spotlights in my scene to have a homogenious enlighted crystal. but is 13 lights not way to much? there must be a method for using less than 10 or even 5 lights...?

spotlights have no decay/area enabled, also it isn´t rendered with GI/Caustics nor FG cause that didn´t give much improvement but increased rendertime a lot.

if anybody has any comments how to improve the renders, please do so!

Hey man, glad you posted what you got.

They look really cool, have you thought of pushing any of hte material attributes above the 1 value to see if theres any effects on it?

I kind of cheated on my diamonds though by adding a HDR to give some colour bleed onto the surfaces so they wernt pure refractions

yes I raised the specular color from l_glas shader to 1.5 but therefore decreased the decay from 80 to 15. at first I tried too using hdri. but the shader with alone spotlights creates enough color to leave out additional reflection supporters.

I´ll do some testing now and show how different settings affect the final image. what I can already say is that pushing the specular value above 1 is tricky cause 1.5 is even more than enough. it blows polys which are facing towards the camera. I guess a range of +-0.1 is proper.