Page 1 of 1

Type of Glass?

Posted: Sat Feb 05, 2011 3:18 am
by tarikb
Can anyone explane types of glass, and how can someone use all type of glass, because only thine glass doesn't appeare black.

THANKS

Re: Type of Glass?

Posted: Sat Feb 05, 2011 4:21 am
by galinette
Hello,

Non-thin glasses are meant to be applied to volumes only.

This means, if you want to make a sheet of glass, for instance in a window, you must model it as a cube (and not as a single polygon) with some thickness (standard glass sheets have 4mm to 10mm thickness). Otherwise, it will appear black.

Etienne

Re: Type of Glass?

Posted: Sat Feb 05, 2011 4:52 am
by Bosseye
Galinette is correct (as always) - if you want to use any glass other than the 'thin glass' then you need to have a volume, ie draw a box in sketchup and apply the glass material to both sides for it to work. If you apply glass to a single plane in sketchup it comes out black and shiny.

I think thin glass is quicker to render though? But won;t give you quite as realistic results as a proper glass material

See below, on the right is a single pane, renders black - on the left a volume (box) renders like glass.

Image

Re: Type of Glass?

Posted: Sun Feb 06, 2011 2:30 am
by Zom-B
Bosseye wrote:If you apply glass to a single plane in sketchup it comes out black and shiny
only because you render it from behind /normals facing inside). from the other side you have a different result ;)

Re: Type of Glass?

Posted: Mon Feb 07, 2011 5:47 am
by Pibuz
BY THE WAY, you get an incorrect result if you apply a specular shader to planar geometry.

Some time ago I had a very interesting discussion with Thomas (aka Lycium): he told me to try and use only the specular shader, instead of the Thing Glass. He strongly supports the correspondence between reality and modeling, because this points the rendering engine's development unidirectionally towards realistic algorithms and less to biased shortcuts, so the result can be more real-like. A good exemple can be the new "architectural glass" algorithm.

To make a long story short, always model volumes, because glass can be only tridimensional. 8)

Re: Type of Glass?

Posted: Mon Feb 07, 2011 9:38 pm
by Bosseye
Zom-B wrote:
Bosseye wrote:If you apply glass to a single plane in sketchup it comes out black and shiny
only because you render it from behind /normals facing inside). from the other side you have a different result ;)
Not me squire! See below, the glass preset comes out black and shiny even if applied to the correct face on a single plane.

The red arrow is just for orientation so you can see I've rotated the view to show the back face (pure black as you know) The other box obviously shows the glass preset applied to a volume where it works correctly.

Image

Re: Type of Glass?

Posted: Tue Feb 08, 2011 9:05 am
by tarikb
Thank you all, very much. You have helped me a lot.

Re: Type of Glass?

Posted: Tue Feb 08, 2011 6:35 pm
by Pibuz
Interested stained glass and grass. Maybe a little too much DOF, and underexposition.. Could you make a lighter version? :mrgreen:

Re: Type of Glass?

Posted: Sat Feb 12, 2011 12:16 am
by tarikb
can you explain me what do you mean by DOF and expo... Jes i can make brighter version :) Thanks

Re: Type of Glass?

Posted: Sat Feb 12, 2011 1:23 am
by Pibuz
DOF = Depth Of Field, which basically means the distance put on focus. Higher number (e.g. f/22) results in clearer objects (I'm simplifying A LOT), low numbers (e.g. f/2) result in more out- of-focus objects.

Increase the ISO value to adjust the exposure: higher numbers mean lighter image.

Re: Type of Glass?

Posted: Tue Feb 15, 2011 8:16 am
by tarikb
THANKS