smr_VIZ

In MR, there are several Arch & Design preset materials. I have some questions for the solid glass material. I guess in theory, the refaction will determine the glass color. So I gave a color to the color slot in refaction area. But Now I am confused. What is the role for the diffuse color. If I assign a color to the diffuse slot, it will also influence the glass color.

Does it mean the diffuse determine the original glass color. The refraction decide the glass color after the light pass through it?

Guys, please enlighten me if you have clues.

Justin Hunt

yes, if you really want to get into it, look at the advanced rendering tab, there are more refraction options. The max depth colour is great, although you have to change the shadow type from simple to segment to get the full effect. Although keep an eye out for shadow artifacting when rendering with segment.

JHV

Brian Bradley

Hi James,

Something you have to keep in mind is the fact that
the A&D shader is designed for physical correctness.

Diffuse, reflection, refraction (transparency) are all
interacting with one another. If an object is opaque
with a matte surface then most of the look will come
from the diffuse slot. if it is completely see
through (glass) then the diffuse slot has little or no
effect at all and colours are derived from the light
passing though the medium.

Massively simplified I know, but the basic principle is
there. :-)

Regards
Bri

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MasterZap

The diffuse isn't related to the *transparency* of the glass, but the glass surfaces diffuse reflectance (if any).

Now, which one of these are the "color" of the glass is rather a semantical question. "Depends on what you mean when you say color", basically.

Glass may indeed have small small amount of diffuse reflectance, but in general you would have the diffuse amount spinner set to 0 for glass.

Glass may, however, often have a little bit of translucency. I generally recommend to turn on translucency for glass, set the weight to about 0.1 and the translucency color to white (wince this is filtered "through" any "refraction color" you put in).

The "refraction color" is *normally* the "glass color", but in real, physical glass the "color" of glass comes from internal absorbtion. In most cases (especially uniformly thick window panes) the difference between these two doesn't matter.

But basically, you put the "glass color" *either* in the "refraction color" OR in the "max depth color" in the refraction section advanced options.

However... since all this is mentioned in the manual.. why do you ask

/Z

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smr_VIZ

Wow. All these are great explanations from different areas. I like it. Thank you, guys.

MasterZap: In Falloff map, the black color will allow the light pass through it. The white color won't. But you put white in translucency. Are you sure? I will do a small test later.

daveb867

zap's method works a treat, that is the method that i tend to use when creating glass materials using the a&d shader, i'm just rendering a couple of examples of a standard wine glass model using zap's technique for colouring the glass, will post them when they are complete.

my machine is rubbishly slow and not very high spec, plus i'm at work so should be doing work they won't be too long tho and hopefully you will be able to see how nice the glass can look when using these techniques.

the next step for extra realism would be for my to incorporate some hdri into my scene, the scene i have used is just lit with two sky portals as area lights with the opiton to make them visible turned on

daveb867

and as promised

this is the a&d solid glass preset, with the diffuse set to 0

translucency on, set to 0.1, and set colour to white

then clear glass has refraction colour set to white

and coloured glass has refraction colour set to the blue colour you can see

Attached Images

	clear glass.jpg (4.6 KB, 34 views)
	coloured glass.jpg (6.2 KB, 41 views)

daveb867

and another quick test using the same technique only this time i have used the physical glass preset, and incorporated caustics to see what effect the transparency colour has on the caustic effect

Attached Images

coloured glass and caustics.jpg (8.7 KB, 44 views)

daveb867

i've just been playing with the transparency colour to add detail to the glass such as logo's etc, it works, however i feel there is something not quite right about the rendering but i can't figure out what it is?

if anybody can spot something to make this rendering better then please feel free to say so

Attached Files

closeupglass.zip (133.4 KB, 20 views)

smr_VIZ

daveb:

I like your small tests. I used to do this too.

Did you have a test for architectural glass put in a scene? If you like, how about we share what we have so far? I am pretty OK with VRay, but very basic in MR for now. Since my firm don't have VRay, so I will spend more time in MR.