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Making glass reflective

Posted: Tue Jul 24, 2007 8:39 pm
by Richiev
Hi there,

Currently I am (still) working on an architectural visualization, in a former post I got some good help with lighting, now I need some guidance on making glass reflective :idea: .

I am using the Specular transparant + glass material, should I use glossy transparant or specular with it? I don't see any reflection so far, did I miss another setting???

I use Blender 2.44 combined with Indigo 0.8

PS the renders are starting to look pretty awesome thanx to Indigo

Posted: Tue Jul 24, 2007 8:44 pm
by CoolColJ
set precendance to 2, set IOR (index of reflectance) higher than 1.0 then you will get reflections :)

Posted: Tue Jul 24, 2007 8:47 pm
by Zom-B
precedence is somehow related to the IOR...
no idea what exactly it is, but it changes the way glass breaks light!
Once Ono told that for glass 10 to 11 is ok...

Posted: Tue Jul 24, 2007 9:11 pm
by Richiev
Great guys (girls?), thanks again. The IOR makes the difference, it instantly makes the glass look it actually is glass...

Any ideas when glossy transparant should be used and when specular (With the Specular material)?

Posted: Tue Jul 24, 2007 9:11 pm
by DaveC
Precedence is not related to IOR. Precedence is simply the priority given to the medium over other mediums sharing the same space. If water and glass are in the same space in your scene and water has a lower precedence (or priority), the glass gets rendered. So, as long as the glass has a higher precedence than any medium it is inside of, it will be rendered properly.

If it is inside a smoky medium which has a precedence of 3, for example, the glass must have a precedence of greater than 3.

IOR will control the reflections.

Posted: Tue Jul 24, 2007 9:24 pm
by Zom-B
Glossy Transparent material is some kind of "rough" glass, like milky glass.
the lower the exponent, the less the less you can actually look through it.

here the right grey glass ball is using a glossy transparent material:
Image
DaveC wrote:Precedence is not related to IOR. Precedence is simply the priority given to the medium over other mediums sharing the same space. If water and glass are in the same space in your scene and water has a lower precedence (or priority), the glass gets rendered. So, as long as the glass has a higher precedence than any medium it is inside of, it will be rendered properly.

If it is inside a smoky medium which has a precedence of 3, for example, the glass must have a precedence of greater than 3.

IOR will control the reflections.
In theory you are totally right dude, it should only manage the hierarchy of materials!!
but try some experiments for glass using different Precedence numbers, and you'll see the difference!

Posted: Tue Jul 24, 2007 9:32 pm
by CoolColJ
precendence of 1 with SSS = instant curtain or foam material
bump precendence to at least 2 and you get glassy material

that stumped me for a long time.... :)
along with exponents, I still don't really know these

Indigo really needs a wiki manual or something ...

Posted: Tue Jul 24, 2007 9:38 pm
by OnoSendai
Indigo already has a rather detailed manual.
http://www.indigorenderer.com/joomla/in ... &Itemid=62

Posted: Tue Jul 24, 2007 9:42 pm
by CoolColJ
yes, I've gone through the PDF, but it doesn't really detail every instance of the syntax and what not IMO

Posted: Tue Jul 24, 2007 10:19 pm
by DaveC
The main reason, the biggest reason that a precedence of 1 on glass might not give great results is that the medium of air, the default medium that your entire scene is in, has a precedence of 1. This means that the glass and the air are fighting for the right to be rendered at the same point in space. Your mediums should ALL have a higher precedence than the surrounding atmosphere.