Understanding Materials and Shading

Tired of everything you make being drab and gray?

In this chapter, you’ll learn how to add color to your models using materials. First, you’ll learn about materials and how they work. Then you’ll learn about a new workspace: the Shading tab. You’ll learn how easy it is to make your own materials, and you’ll set up materials for your mushroom and your tree.

Here’s what you’ll be able to do by the end of this chapter:

• Create materials for your models
• Edit materials to get the colors you want
• Understand the basics of the Shader Editor
• Add multiple materials to one model

You’ll start by learning what a material is, and what it does. Then you’ll move on to creating your own materials.

Understanding materials

Before you can understand materials, you need to learn a little about how 3D rendering works in Blender. The whole process is done by a complicated piece of software called a rendering engine. There are two different rendering engines in Blender: one is called Eevee, and the other is called Cycles.

The rendering engine does all the hard work of rendering. It calculates what your 3D scene looks like from the point of view of a camera. It simulates the effect of light emitting from a source (like the default one we always delete) and calculates how that light would bounce around the scene, what it would illuminate, and what would remain in shadow.

But light reacts differently with different objects. For example, light hitting a smooth, shiny mirror reflects perfectly off of it, but light hitting a piece of stone reflects differently since the stone is rough. See Figure 6.1 to know the difference:

Figure 6.1: Shiny versus rough...

The Shader Editor

In this section, you’ll learn how the Shading workspace is laid out and what the different parts are. You’ll make your first material and understand the gritty details of how materials work. You’ll also create your first material.

The Shading workspace is where you’ll be working in this chapter. Shading is the process of creating and working on materials for objects.

Open up a new Blender file and switch to the Shading workspace by clicking the Shading tab at the top of the window.

Figure 6.2: The Shading tab

The Shading workspace is divided into six parts. In the middle is the 3D viewport. It looks a little different than usual since it’s set to Material Preview mode. Below the 3D viewport is the Shader Editor. This is where you’ll use building blocks called Shader nodes to build materials.

On the right-hand side, there are the Outliner and Properties functions as usual. It’s...

Nodes in Blender

Nodes are like pieces of materials. They’re simple, modular building blocks that each perform a specific function. You connect their sockets to build more complicated materials. There are two default nodes in the Shader Editor: Principled Shader and Material Output. For simple projects, like the ones in this book, you won’t need any more nodes than these.

Let’s start with the Principled BSDF node.

The Principled BSDF node

The Principled BSDF node is the most useful shader node. BSDF stands for the Bidirectional Scattering Distribution Function, and it’s a program that calculates how light bounces off a surface.

It’s not too hard to see why BSDF exists. Shader nodes are the only kind of node you can connect to the Surface output.

The Principled BSDF node has a lot of inputs, as shown in Figure 6.4:

Figure 6.4: The Principled BSDF node

However, most of the time, you’ll only be focusing...

Materials for the tree

Time to improve your boring gray tree!

Now that you know how materials work, this will be pretty simple:

1. First, find and open the .blend file where your tree is saved.
2. Now, select the leaves option. Switch to the Shading tab.
3. Click the New button at the top of the Shader Editor to make a new material. Name it Leaves. (If there is already a default material there, simply rename that one.)
4. Now we need to adjust the Principled BSDF node. First, change the Base Color setting to a nice leafy green.
5. Leave the Metallic value at its default of 0, but raise Roughness to 0.7 or 0.8 so the leaves aren’t too shiny.

Figure 6.6: Node for the Leaves material

That’s all for the Leaves material. Now we need to apply this material to the other leaf objects so all the leaves are the same color. This is easy:

1. Select any leaf object.
2. Click the material drop-down menu and choose your new Leaves...

Materials for the mushroom

Creating materials for the mushroom will be a little more challenging than for the tree since the mushroom is a complete object and needs different materials on different parts of the object. You want to put a red material on the top of the mushroom and a different color on the stem.

Blender makes this possible using something called material slots. Each slot holds one material. An object can have as many slots as it needs.

Each slot is assigned to a set of faces. The slot’s material will be applied to those faces.

For our exercise, our mushroom will have two slots. One slot will have a red material, and it’ll be assigned to all of the faces that form the top of the mushroom. The second slot will be assigned to the stem part of the model, and it’ll use a different material.

Open up the Blender file for the mushroom you built in Chapter 5.

First, we’ll set up two different material slots on the mushroom. One slot...

Summary

In this chapter, you finally added color to your drab, gray 3D models. You learned what materials are and how to set them up in the Shader Editor. You learned how to edit and build simple materials using the Principled BSDF node.

You even learned how to assign materials to different faces of an object.

That’s a lot!

If you only remember one thing from this chapter, make it how materials work: each object has material slots, and each slot holds a material.

In the next chapter, we’ll dive back into modeling and teach you how to make some low-poly vehicles.