Coloured Perspex (or Glass)

[Morne]

I'm having a hell of a time today for some reason to make coloure glass. I have light pink, citric orange, etc. All bright pastel colours. No matter what I do, my sample in my material editor is just not looking like I want. Mostly comes out very dark, (almost black) or very dark red.

I've tried in the refraction slot, and also tried fog colour

[leehumphries]

post an example..

Im no expert but i have recently had to create Red Glass for glass chandelier made by Andromeda. I found it really tricky to actually light the inside of the glass like in real life.

I had two versions of the glass

one was - diffuse Black / refl - white 240 odd / refraction - white 252 / fresnel on / affect shadows on / reflection on inside / fog deep red with multiplier of 0.035

second - diffuse red / refl - same as above - refraction - light red / all the rest as above with no fog colour

I found the second option made the room too red,from the glass light..The fog version i didnt get enough red thru the glass onto the walls etc.

Would be interesting to see what other people use for coloured glass.

[Morne]

I'm using diffuse black, reflect white with IOR 1.6. Refract the colour and IOR of 1.1. But I just dont seem to be able to get bright pastel colours out of it. The colours comes out very dark. I don't want to stick the colour on the diffuse, as apparently things that has refraction takes ages to render with non black diffuse

[leehumphries]

what value is your fog multiplier on

[Morne]

fog is on 1 (with white fog)
Now I've copied the refraction colour to the diffuse colour and starting to get better results. So far not seeing much of a change in render speed. Not there yet, but getting there

[peterguthrie]

might depends on scene units, but try putting the colour in the fog and with a lower multiplier like 0.01

from looking at a recent material for greenish slightly frosted glass, i had the following:

diffuse 211,211,211
reflect white ior 1.6 glossiness 1.0
refract white ior 1.6 glossiness 0.8
fog 133,220,172 fog multi 0.02
affect shadows and channels: yes

If you dont want it frosted then change diffuse to black and refract glossiness back to 1.0 (i think that should work anyway)

[Morne]

If you dont want it frosted then change diffuse to black and refract glossiness back to 1.0 (i think that should work anyway)

Problem is you dont see the correct result in the material browser this way. It just shows a very dark (almost black) sample

[peterguthrie]

is that such a big problem? I never trust how materials look in the mat browser

[Morne]

yes because now I have to render 10 times before i get it right. With the material browser I can accept if it is withing 50% of wysiwyg. But if it is only like 5%, that is rediculous

[peterguthrie]

the fog value is always tricky, fire up vrayRT maybe

[joconnell]

The problem with the material editor and shiny or see through materials is that those type of materials are so heavily influenced by what they reflect and refract. If you've got a metal material it'll look totally different depending on the environment around it, and a glass material will be brightened / darkened depending on the colour values of whatever's behind it. The chequer map in the background of the material editor isn't a good measure.

[MoonDoggie]

Or tweak the fog multiplier with "Tweaker" script if you don't have VrayRT (self-script plug)

[simmsimaging]

The only way to get coloured glass that behaves accurately, in my experience with Vray, is with fog colour like Peter said. The mat editor *always* looks way to dark for me. RT is a big help for this, but if you don't have it then you don't really have much choice except to test render. You can always use Colin's tweaker script and grab a coffee

I would suggest though that you leave the diffuse at black and the refract colour at full white if possible and do all the colour with fog unless you want to create more of a window film effect. If the glass is slightly murky and has a diffuse component you may have no choice.

b

[MoonDoggie]

Ha, thanks Brett, that's _exactly_ what I just did, but it's more of a cappuccino.

[peterguthrie]

I will check out your script now Colin, but I'll be opting for a beer!