Whenever I try to render even the simplest scene, such as a “glass” cube, using Cycles, the cube (or any object) just looks dark or gray. With the default lamp it’s the same. I have added one or more planes with emission material(s), but then you see the planes reflected in the cube, so some of it looks a little like glass but you can see darkness where the reflections end. I have even tried enclosing the entire scene (cube, planes, lamp(s) and camera inside a sphere, and giving the sphere a soft emission material, but it doesn’t help. I just can’t seem to get a lighting situation that makes a simple “glass” cube sort of floating in space, with a soft glowing light reflecting the way real glass would. It’s not as much of a problem in Blender render, but the results aren’t as realistic as what I’ve seen others do with glass/ice etc. in Cycles. Any ideas or help is welcome. Oh, and I have seen references to world lighting, but I don’t see where to find any way to access it. I’ve looked at at least 100 or more video tutorials, but some of what they are doing just doesn’t seem possible, since many of the things they are clicking or selecting from menus just aren’t there in my Blender. I have the latest version (as of two weeks ago), so maybe the tutorials are older versions.
Since default lamp is a tiny mathematically defined spot somewhere in the imaginary default gray sphere wast amount of that color reflects and refracts in Glass node equations… That much bigger than yours gray sphere also emits light rays. In real conditions each and every light ray is different, glass reflects what’s around it and you see what you so nicely described.
I would not want to tell true lies and i might be off the latest development, but from what i know there is still work to do on Cycles to see it correctly deal with all aspects of Glass/Light relationships.
So far on a lot of occasions Glass node is substituted or used in combinations with other nodes to get desirable result. For some effects even different render engines are used - yafaray, Lux are couple of available almost out of the box combination with Blender.
To deal with default gray - in Node editor window on menu next to the Material icon is World icon - that opens nodes to change World colors. Background node can use Image texture node, several Backgrounds can be Mixed, plenty of possibilities to get world colorful.
Glass most often is combined or substituted with Transparent/Glossy mix which has Fresnel mix factor plugged in.
Double and triple check your Object’s face normals, especially when that is a glass with water or different liquid in it.
See information on light paths, count how many times light ray crosses borders of different substance surfaces. If this number is set too low Cycles will paint it black.
Thanks for responding, but when I open the node editor window there is nothing there but a grid. How do I put the cube in that window? I tried cut and paste, but it doesn’t work. But when I go back to the default window, the cube is still there.
Simple.
You do not put Cube there. You deal with material creation for cube which is selected and still in 3d editor window.
Or create lights for World; you use Nodes in these windows.
Open node editor window,(make sure default cube is selected and render is Cycles not Blender Internal), choose brown sphere icon. Click New.
You should see 2 boxes connected with wire. That’s a material.
Choose blue sphere icon instead of small cube on menu - you’ll be in the World creation workspace…
There is nothing in that node editor window but the grid. The 3D window is replaced by the grid but it’s empty. The controls, icons and interface to the left of the window and below it remain the same as they were in the opening screen when the 3D window was there. Those icons are for the 3D window. Where are the icons in the node editor window? I have Blender 2.68 and I haven’t changed anything from the default opening screen, etc.
Picture’s better, i figure.
http://www.pasteall.org/pic/58851
Edit: I usually change Timeline to Node Editor and pull border up a bit. On top of the screen where it says Default, you could use Compositing layout from dropdown.
OK, well thanks for trying to help, but I have no idea what you are talking about. Those things you are talking about are not on my Blender screen. You have two different windows open at once, and I only have one at a time. My screen just does not look like yours. Thanks anyway.
Basically, until you either model a whole scene, or setup better lighting, just add a HDRi world image, that will provide you with reflections so the glass looks real
I don’t know what an HDRi world image is, nor how to add one. I don’t know how eppo has two windows open at once in his images that he posted. I haven’t seen anything about these in the tutorials that I’ve watched. Are these things in a professional version of Blender? I only have the free version, so maybe that’s why mine is limited.
There is no professional/free differentiated versions of Blender afaik.
See this video how to change window layout to fit your needs.
This site has covered a lot of related to using Blender issues; video i linked also is done by Neal Hirsig.
http://gryllus.net/Blender/3D.html
Thanks, I will follow those links soon.