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- View Offline
- Understanding material channels
- Applying materials via projection
- Limiting materials with selection tags
- Texturing type
- Using Falloff to limit the effects of lights
- Working with visible or volumetric light
- Painting on objects and textures with brushes in BodyPaint
- Hiding seams with projection painting
Skill Level Beginner
Transparent objects are really about three things: what you can see through the glass, how you can see through the glass, and then what you see reflected in the glass. When you answer those three questions, you'll end up with a really decent-looking glass material. I've got a very simple scene here. I've got a Sky object that surrounds it, and the sky has this gradient material on it. It's just a series of bands. That's going to give us a nice reflective pattern on our objects. I've got these different spheres. Now, the ones that have stripes on them, we're going to leave them alone, we're not going to touch.
We're going to focus on the gray ones. The reason I have the striped ones in there is to give our objects something to see through, because remember, glass is about what you can see through it. Let's create a new material by double-clicking in the Material Manager, and let's call this material Glass. Let's take that Glass material and apply it to the empty cube and then apply it to the empty sphere. The reason I have both a sphere and a cube is that glass looks very different based on the shape of the object that it's being applied to.
Let's take a look at our Glass properties, and I'll select the Glass in the Material Manager and take a look at its attributes. If we look at the Basic properties here, we've got Color already on. We know we're going to need that. We're going to turn on Transparency, and let's focus on just the transparency for a moment to take a look at the properties. Then we'll come back to the Reflective and the Shiny bits. So let's start off by making it transparent. Here in the Editor window, let's hit Command+R or Ctrl+R and render our scene. You can see that both our sphere and our cube are gone. So we don't have to keep hitting Command+R or Ctrl+R.
Let's bring up the Interactive Render Region. The keyboard shortcut is Option+R. And let's take the Quality level up to 100%. Let's also enlarge the Interactive Render Region. It's a little bit hard to see the corner of the Interactive Render Region. In order to do that, let's turn off the Sky object. I'll double-click on the top gray dot. Now I could see my Interactive Render Region, and let's drag that down just a bit. It makes it much easier. The top gray dot refers to whether or not the object is visible in the Editor window.
The bottom gray dot is whether or not the object is visible in the render engine. So, by leaving the bottom gray dot on, we now see our object in the render, but we don't see it out here in the Editor window. Now that we've got our Interactive Render Region set, we can focus on the materials again. Let's deselect the Sky object by clicking over here. Let's go back to our Glass material. The only type of glass that really is completely transparent is window glass, and most other types of glass have a shape to it, and that shape creates something called an index of refraction.
The index of refraction is how much an object bends light as it passes through. Window glass has a very low index of refraction, plus it's perfectly flat so that it does not bend light. The lenses on your eyeglass bend light in a very specific way, because of the shape of the lens. In order to create that index of refraction, we have to turn on the Refraction Index in the Transparency option. So in the Transparency settings, the Brightness option controls whether or not the object is transparent.
If we dial this back a little bit, you'll see that our objects become more opaque. 0 is fully opaque and 100% is completely transparent. Right below that is the Refraction Index. 1 completely passes light without bending it at all. 1.2 is standard glass. Let's go 1.2. And watch what happens when I do that. You'll see that now we have a very different reaction from our glass shapes out here. The sphere is bending light all the way through it.
The cube is bending so much light we can't even see the sphere behind it anymore. I'll take the Refraction Index from 1.2 down to 1.01. That index of refraction is bending it every so slightly. Let's crank it up just a little bit more, to like 1.04. Now we've got a nice refraction on the cube and on the spheres. It's a nice balance between those two shapes. The next component of transparency is what you can see on the surface of the glass.
So, glass is reflective. Unless you were to hit it with the bead blast or something like that to change to surface property, it's always going to be reflective. So let's go to the Basic properties and turn on Reflection. When we do that we're going to get a perfectly reflective surface. Because our object is 100% transparent, we can't see any of those reflections. So in order to get the reflections to show up, we have to start to dial back the transparency a bit. So in the Transparency option, let's bring it from 100% brightness on the transparency, let's try 95%.
As soon as we do that, we start to see the reflection. You can see them here in the preview. We can also see them here in the surface of our objects. They got a little bit frosty-looking because of the gray environment that they're sitting in. They reflect that gray environment. If I were to change the environment to something a little more obvious--let's go to the Sky material and instead of this gradient that we have in the Luminance channel, let's add something that's a little more obnoxious. I'm going to go to the pulldown and in the Surfaces option, I'll add in Earth.
Earth is just a model blue and green texture. When I add that in there, you'll see that we've got now this blue and green going all through our object in the background, and it creates a very different impression on the surface. I am going to undo that--Command+Z or Ctrl+Z--to get back to our nice gradient. Glass is a really subtle effect in 3D. Take a look in your cupboard and look at some of the glasses that you see there and try re-creating some of them for practice.