Working with Models, Materials, and Textures in Unity Game Development
This chapter is from the book
This chapter is from the book
This chapter is from the book
The Basics of Models
Video games wouldn’t be very video without the graphical components. In 2D games, the graphics consist of flat images called sprites. All you needed to do was change the x and y positions of these sprites and flip several of them in sequence and the viewer’s eye was fooled into believing that it saw true motion and animation. In 3D games, however, things aren’t so simple. In worlds with a third axis, objects need to have volume to fool the eye. Because games use a large number of objects, the need to process things quickly was very important. Enter the mesh. A mesh, at its most simple, is a series of interconnected triangles. These triangles build off of each other in strips to form basic to very complex objects. These strips provide the 3D definitions of a model and can be processed very quickly. Don’t worry, though; Unity handles all of this for you so that you don’t have to manage it yourself. Later in this hour, you’ll see just how triangles can make up various shapes in the Unity Scene view.
Built-In 3D Objects
Unity comes with a few basic built-in meshes (or primitives) for you work with. These tend to be simple shapes that serve simple utilities or can be combined to make more-complex objects. Figure 3.1 shows the available built-in meshes. (You worked with the cube and sphere in the previous hours.)
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FIGURE 3.1 The built-in meshes in Unity.
Importing Models
Having built-in models is nice, but most of the time, your games will require art assets that are a little more complex. Thankfully, Unity makes it rather easy to bring your own 3D models into your projects. Just placing the file containing the 3D model in your Assets folder is enough to bring it into the project. From there, dragging it into the scene or hierarchy builds a game object around it. Natively, Unity supports .fbx, .dae, .3ds, .dxf, and .obj files. This enables you to work with just about any 3D modeling tool.
Try it Yourself: Importing Your Own 3D Model
Let’s walk through the steps required to bring custom 3D models into a Unity project:
- Create a new Unity project or scene.
- In the Project view, create a new folder named Models under the Assets folder. (Right-click the Assets folder and select Create > Folder.)
- Locate the Torus.fbx file provided for you in the Hour 3 folder of the book files.
With both the operating system’s file browser and the Unity editor open and side by side, click and drag the Torus.fbx file from the file browser into the Models folder that you created in step 2. In Unity, click the Models folder to see the new Torus file. If done correctly, your Project view will resemble Figure 3.2. Notice the Materials folder that was added for you. You will learn more about this later.
FIGURE 3.2 The Project view after the Torus model was added.
- Click the Torus asset in the Models folder and look at the Inspector view. Change the value of the scale factor from 0.01 to 1 and click Apply.
- Drag the Torus asset from the Models folder onto the Scene view. Notice how a Torus game object was added to the scene containing a mesh filter and mesh rendered. These allow the Torus to be drawn to the screen. If you click the Torus object, you see how it is made up of many connected triangles.
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Models and the Asset Store
You don’t have to be an expert modeler to make games with Unity. The Asset Store provides a simple and effective way to find premade models and import them into your project. Generally speaking, models on the Asset Store are either free or paid and come alone or in a collection of similar models. Some of the models come with their own textures, and some of them are simply the mesh data.
Try it Yourself: Downloading Models from the Asset Store
Let’s learn how to find and download models from Unity’s Asset Store. We will be acquiring a model named Robot Kyle and importing it into our scene:
Create a new scene (click File > New Scene). In the Project view, type t:Model into the search bar (see Figure 3.3).
FIGURE 3.3 Steps to locate a model asset.
- In the search filter section, click the Asset Store: 999+/999+ button (see Figure 3.3). If these words aren’t visible, you may need to resize your editor window or Project view window.
- Locate Robot Kyle and select it.
- In the Inspector view, click Import Package. At this point, you may be prompted to provide your Unity account credentials.
- When the Importing Package dialog opens, leave everything checked and select Import.
There will now be a new asset folder called Robot Kyle. Locate the robot model under Assets > Robot Kyle > Model and drag it into the Scene view (see Figure 3.4). Note that the model will be fairly small in the Scene view; you might need to move closer to see it.
FIGURE 3.4 The Unity project with Robot Kyle Added.
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