I’ve made a scene of some glass and one regular domino. The blue-ish dominoes are supposed to be made of glass. The top and other edge parts of those dominoes turn out to be black when I render. Since the floor material is not black and it is well lit, I don’t know what the problem is. Would real glass look like that?
Here, see for yourself:
Your picture isn’t working for me, but I think if you turn up the “Depth” setting for your glass material under RayMirror and RayTransp, it should fix your problem. Hope that helps.
I used YafRay as the renderer, so the “Depth” settings are in the “YafRay GI” area in the Scene tab. I turned up both settings for Depth and CDepth (indirect light bounces and bounces inside objects) and did a test render. It didn’t change anything. I will try to render with Blender Internal and will get try with those settings even higher to attempt to fix it. Thanks for your help.
heres his image…
copy+paste link
ic3.deviantart.com/fs11/i/2006/228/a/0/Proto_Domino_Scene_by_anthonyesau.png
for some reason it wont display on this page
and no it dosnt look like that in real life
http://ic1.deviantart.com/fs11/i/2006/229/d/c/Proto_Domino_Scene_by_anthonyesau.png
Here is a pic with a closer view also (if you can’t see it in the opening message). I tried the Blender Internal renderer and it worked… to an extent. The quality was such, that compared to YafRay, was unthinkable in a final version. It also didn’t show the glass color, but I didn’t change any material properties in the transition so can I blame it? Higher depth values didn’t work either. I even tried the shadow bias thing (I don’t quite know how to properly use it, but it said something about fixing self shadows so I went for it).
Sorry about the broken type links to pictures. To get it to view (in Firefox at least) copy this link location:
http://ic1.deviantart.com/fs11/i/2006/229/d/c/Proto_Domino_Scene_by_anthonyesau.png
and paste it into the address bar and press enter.
So now, for the real update. I tried many things, like rotating dominoes which worked, but is not the position I want them in. I also changed something in the material settings called Absorbtion Distance. I lowered it and all the sides turned that dark color. I set it higher and the dominoes just became more clear with the edges still dark. With the dominoes having no Ray Mirror, all edges except the front and back are dark. I also changed the strengths of GI versus arealights, etc in the YafRay GI menu. When the arealights provided the most light, the dark edges turned bright white! How annoying is this?
Please help if you know anything about this!
try putting the ray depth higher.
Make sure your index of refraction (IOR) is the one you want.
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/indrf.html
If none of that works that may just be how glass looks.
I know that if you look at glass from a low angle it appears black some times
http://en.wikipedia.org/wiki/Total_internal_reflection
Yeah, Im with Imperitor…its most likely the IOR…
I remember having a similar problem once. I didnt know about the forums yet, and spent forever screwing the all the material settings before i figured it out…what a waste of 3 days 
Edit: But just for kicks you may try moving your camera(Or turning off AO, if your using the blender renderer)
Good luck.
Look at how the glass’ edge is on this big glass chunk:
I tested different IORs and higher ray depth, but nothing changed. If anyone thinks they can help more if they had the .blend file, just ask.
Well, now I feel a little stupid. In the materials settings, when using YafRay, the tab “Mirror Transp” has ray mirror and ray transparancy settings. There’s a dropdown with several options one “Color Glass” and another “No Reflect/Transmit” among others. I thought that these were just presets for materials, but it turns out that “No Reflect/Transmit” is different than “Color Glass” with the same settings. I had it on the no reflect/transmit and the colored glass basically fixed my problem. The edge is still dark, but it has better qualities that look more like glass and some things can be seen through. The color of the material had to be lightened considerably through the process. If anyone knows how the differences in “Color Glass”, “No Reflect/Transmit”, etc work in YafRay, please tell me.
yeah, actually, that could be it, sorry about the last one(i lead you wrong, IOR being refraction afterall) I would check your filtering options for your glass, and obviously, make sure your glass is white( sorry, u probably allready got that )
BTW Color glass is a preset that makes the fresnel, and calculations in such a way, that you keep the color( which you probably also got) No reflect, is obviously a plain transparent material, no Ray-Mirror. Good Luck
Peace out,
Drew
I’d like to see how it turned out with those settings changed.
Now, photographically speaking, I think that it generally worked okay that the edges were fairly dark – it was realistic, except that there was no specularity and the edges looked like they had been wrapped in gaffer-tape.
Anyhow, in the long run, the unimportant edges of things like glass objects are often needing of special lighting treatment in a photographic studio. There might be a rim-light whose sole purpose would be to illuminate those edges in an interesting way, to help define clearly where the edges are, how soft or hard the material is, and that the edge is well-beveled. Other lighting may be chosen to carefully make-clear the effect that light is shining (refracting…) through the glass to the solid white domino. All of this lighting being done so subtly that it does not call attention to its own existence.
A certain amount of “what feels ‘missing’” in this shot, vis-a-vis (say…) a commercial photograph of the same subject, might be this. Some really good books on studio still-life photography can be a very valuable reference, as can some time spent in a good ol’ fashioned (digital, now…) “film” studio. Actually doing it. Lighting it. Watching it done. (“Oh wow, I didn’t even notice that light until you turned it off…” etc…)
I had not intended for this to be the final image of the object, just a test of how things could look. You are completely right that it needs to be composed better, and as for the lighting, I just let the skydome effect of Yafray do that. I need to brush up on my lighting and compositiong skills so I had set that part of the project off until I had other things completed. I am prettey well satisfied with how things (material and model wise) turned out so far.
Here is the most recent version of this project (took about 5 min to render if anyone is interested).
