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Captain
02-17-2003, 02:40 AM
Hey, I need some good advice for surfacing A Gem...I dont need percentage amounts..but rather I need some advice on the texture part of the areas...lik eparticular luminosity or color channel textures to put on...any advice?


-Captain

Fasty
02-17-2003, 02:49 AM
I know Vangaans made a great gem for a logo id, he'd know, but I haven't seen him around here lately.

http://www.vangaans.com/gallerytv_a.html

here's the one he did, up the top.

Freak
02-17-2003, 03:00 AM
Think coloured glass.....

I can't see why you would use Luminosity?
Of course you can use any attribute for a certain look.

What gems emit Light?
Colour = the colour of your gem.....
(Diamonds i use basically a standard white colour) 240,240,240
You may like to add frac noise texture.

I have presets for Rubies, Diamonds, Opals, Emeralds etc...
They also use pretty accurate colours and IOR..
And of course they have an Air surface...

Reflection maps for gems are critical....
And you can use shaders and gradients to great effect too....

Arte
02-17-2003, 12:06 PM
As someone else mentioned use air polygons or G2 with double sided.

Try a good HDRI image for creating the multiple busy reflections/refractions with a more realistic environment. Other than that, the surface is pretty close to regular glass (remember not to use glass's refraction, air polygons go to 1.001 unless you have trace refraction on). Depending on the type of gem you may want to have some colour filtering. As for luminosity. That would be bad, it can "burn" out your reflections which are vital for a gem.
Basically the busier the image the better it will look I've found.

Good luck.

X

proton
02-17-2003, 03:38 PM
Dave Jerrard (sp?) did an excellent tutorial on this in a book and I think it is online somewhere.....

Celshader
02-17-2003, 08:17 PM
Originally posted by proton
Dave Jerrard (sp?) did an excellent tutorial on this in a book and I think it is online somewhere.....

On Mohh's site right here:
http://www.mohhs.com/lw/pdf/

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