Generating Texture Maps with Cycles

In this chapter, we will learn to acquire or create texture maps both inside Blender and with the help of GIMP. GIMP is a popular, free image-editing program that we will use throughout this book to create texture maps and custom decals. We will begin by exploring ways to find textures online, before learning about the different ways to turn textures into texture maps. We will then apply the textures to our materials in Blender.

By the end of this chapter, you will be able to create, download, and apply your own materials and texture maps in Blender.

The following topics will be covered in this chapter:

• Using texture libraries
• Applying texture maps in Blender
• Creating Roughness maps in Blender
• Baking Normal maps in Blender
• Generating Roughness maps in GIMP
• Generating Normal maps in GIMP

Technical requirements

GIMP will be used in this chapter to create texture maps and modify textures. It can be downloaded for free from https://www.gimp.org/downloads/.

The prepared resources can be found in the Chapter05 folder within the book’s downloadable resources folder, available here: https://packt.link/mA1OU

Using texture libraries

Texture libraries are websites from which you can download a variety of high-quality textures and texture maps. Although most texture libraries charge a subscription fee for full access, they still have lots of textures available for free. Here are some popular texture libraries:

• https://www.textures.com/
• https://ambientcg.com/
• https://polyhaven.com/

To find materials and texture maps on Textures.com, visit the site and find the Library button in the top pane, as marked in Figure 5.1.

Figure 5.1 – The Textures.com home page

Then, click on the PBR Materials section on the left side of the page, as shown in Figure 5.2.

Figure 5.2 – The PBR Materials section

This will open a large library of materials, which include texture maps. You can see this in Figure 5.3.

Figure 5.3 – A library of PBR materials

Clicking on a material will reveal...

Applying texture maps in Blender

We will now apply an Albedo map, Roughness map, and Normal map to a material in Blender using nodes. For this exercise, you can use any material from any of these websites, as they all work the same way.

Let us add the texture maps to a material on a cube:

1. Add a Node Wrangler to a Principled BSDF node with Ctrl + T, and plug it into the base color.

Figure 5.5 – Adding a Node Wrangler

2. Click on the Open button in the Image Texture node, and load the Albedo map. The Albedo map file will most likely have a complex name, but it will end with the word albedo. For example, the file might be named TexturesCom_Wall_BrickPlain3_2.5x2.5_B_1K_albedo.

Figure 5.6 – Opening a file

3. Next, add a second Node Wrangler, and plug it into the Roughness input. In this Image Texture node, load the Roughness map. This image will have the same name as the Albedo map, except...

Creating Roughness maps in Blender

We will now learn to use nodes to convert an Albedo map into a Roughness map and apply it to our material. This method is useful because it gives us direct control over the Roughness map, so we can make changes to it without loading it into an external program every time.

In the following steps, we will use nodes to turn an Albedo map into a Roughness map:

1. Load an Albedo map through a Node Wrangler.

Figure 5.12 – Loading the Albedo map

2. Add a second Node Wrangler, and once again, load the Albedo map into the Image Texture node.

   These nodes should be plugged into the Roughness input, with Color Space set to Non-Color.

Figure 5.13 – Converting an Albedo map into a Roughness map

3. In the second Image Texture node, click on the button marked with 2.

Figure 5.14 – Making a copy of an image

This will make a copy of...

Baking Normal maps in Blender

We will now learn to bake normal maps in Blender using the Cycles render engine. Baking is the process of saving attributes such as color, roughness, or even bumpiness into an image that can be exported or used elsewhere. The features on the surface in Figure 5.17 can be baked into a normal map image so that it can be used to simulate the same features, without actually creating them as a 3D surface. This method will allow us to simulate highly detailed surfaces without increasing the polygon count of our scene.

Figure 5.17 – Surface details

These features are easy to replace with a normal map because they are quite close to the surface, and they appear as bumps rather than separate objects. In the following steps, we will turn these surface details into a normal map:

1. Add a plane right above the surface with the details.

Figure 5.18 – Adding a plane above the surface with...

Generating Roughness maps in GIMP

We will now learn to use GIMP for generating roughness maps. To do this, we will modify a texture in GIMP to turn it into a roughness map. This will allow us to easily create a roughness map for any existing texture. First, we will install GIMP and then we will quickly start creating texture maps.

GIMP can easily be substituted with other image editing programs such as Photoshop or even Paint.NET. The reason we are using GIMP is because it is completely free, and it has more advanced built-in features than other free image editors.

In the following steps, we will install GIMP and use it to create a Roughness map:

1. Visit the link provided in the Technical requirements section of this chapter. Then, select your operating system and download GIMP directly from the website.

Figure 5.27 – Downloading GIMP

2. Follow the Installation instructions provided by the program.

...

Generating Normal maps in GIMP

We will now learn to quickly convert Albedo maps into Normal maps in GIMP. This will allow us to turn any image texture into a Normal map in a few clicks.

In the following steps, we will export a texture as a Normal map:

1. Open the Albedo map in GIMP.

Figure 5.39 – Opening an Albedo map in GIMP

2. Open the Filters menu from the top of the window, find the Generic section, and click on Normal Map.

Figure 5.40 – Applying a Normal Map filter

GIMP will instantly turn the image into a Normal map and offer some tools to adjust the image, as shown in Figure 5.41. You can tweak the settings, but applying the default settings usually works well.

3. Click the OK button.

Figure 5.41 – Confirming the conversion

4. Once again, export the image, and name the file Normal_Map.png.

Figure 5.42 –...

Summary

In this chapter, we learned how to download textures and texture maps from the internet and apply them in Blender using nodes. We then learned how to create our own Roughness maps and Normal maps in Blender, with the help of GIMP. Having access to an image editing program such as GIMP is important because almost any 3D project will require some external image editing, whether it is for texture maps, custom textures, decals, or post-processing.

We also learned how to bake normal maps. This allows us to easily turn surface details into normal maps that we can apply to any material. Baking can also be used for colors and roughness, and it is a great way to convert procedural materials into savable images.

In the next chapter, we will learn how to create some common materials by using the tools and techniques that we’ve learned, combining them with some tips and tricks to make them look realistic on a 3D model.