XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : mia_material/glass shader

06-22-2009, 09:41 PM
So I have a very simple wine glass.

Mia_material, glass solid preset, diffuse color is just a littler darker than white, glossiness just under 1, max trace depth 10, IOR is 1.5, solid is checked rather than thin walled, fresnel reflection is on, ect

Mental Ray, production, caustics with accuracy of 300, final gather with accuracy of 500, raytracing with 10, 10, 20 (turning those 3 up eliminated most of those black pits).

Directional light of 1, other side with a spotlight with .6, rim spotlight in behind with .3

All that gives me the image attached. In the camera attributes, if the background color is the normal black, you can barely see it, change it to a light gray, you see it like in the image. But it seems too clear, the bottom of the glass is very white on certain camera angles render. Seems like it could use something else, but I'm not sure what, this is my first time really using mia_material :eek:

06-22-2009, 10:09 PM
make sure skip inside reflections is unchecked also

06-22-2009, 10:34 PM
make sure skip inside reflections is unchecked also

Yeah thats unchecked, forgot to mention that one

06-22-2009, 11:52 PM
remember its not all about the settings.

take a look at some reference and mimic it, work on your lighting

06-23-2009, 03:07 AM
remember its not all about the settings.

take a look at some reference and mimic it, work on your lighting

Understood, good point. I'm mainly a modeler, trying to get better on the lighting/shaders side of things. Maybe I'm kinda hitting a wall due to being a modeler and theres only so much you can model a simple wine glass. Attempting some GI and other things now, instead of the traditional 3 point lighting.

06-23-2009, 07:10 AM
I think that one thing you're missing is reflections/refractions. That is, your "scene" has nothing to refract currently? It looks like the only reflections are your lights...

Glass "in real life" takes much of its color from everything else around it. If it were perfectly clear, it would be perfectly invisible, much like what you're seeing here.

Another option would be to introduce a microscopic-scale bump map to make the glass more uneven or even a bit wavy. But I think using a large sphere with some kind of image mapped to it would help tremendously to start with. Turn off Primary Visibility on the sphere and away you go!

06-24-2009, 07:12 AM
Agree with infernal darkness. When shading something like glass its all about the reflections and refractions. So most importantly its about the environment.

I was doing a few tests the other week with mia shaders in conjunction with p_dielectric shader. No lights in this scene just a gradient on a background sphere and another self illuminating sphere off screen to the left to give the highlight.


06-24-2009, 08:57 AM
Try thinking in a different way as well, you're trying to recreate a photorealistic scene, a studio shot for a 'catalogue look', right?

Well, when do you see an impossibly clean wine glass sat inside an impossibly clean, glowing hemisphere with invisible lights/camera/cameraman? Never. Add in a couple of tall, skinny self-illuminating white planes (and some very dark ones for contrast) off camera.

06-25-2009, 04:24 PM
Man very helpful posts above, thank you, some of it had me hitting my head with my hand because it makes sense, just didn't think of it. Made some nice progress, will post it soon.

Is it unusual that I ended up having a little more success with the older dia_electric material than the mia? It seems to give some really good results, I guess due to the 2 IOR attributes.

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