Achieving Realism with Texture Maps

Texture maps are special types of textures used to increase the level of realism of a material. Creating and using texture maps is an important part of the texturing process. These maps are usually created by converting a regular image texture into a texture map using special tools. We will use texture maps in this book to add special effects to our materials, such as surface bumps, patterns, and other details. This is beneficial because we can conveniently apply all the details and properties of real-life materials using just a few separate images.

The level of realism in a 3D artist’s work is a key indicator of their skill and professionalism. Being able to create photorealistic works is an important demonstration of an artist’s ability, including photorealistic product images and videos, architectural visualization, and interior design. Having the skills to create photorealistic artwork is by far the best way to impress potential...

Technical requirements

The prepared resources can be found in the Chapter04 folder within the book’s downloadable resources folder, available here: https://packt.link/mA1OU

Using Albedo maps to create a base texture

Albedo map is the term used to refer to an image that we apply to an object to create a basic texture. This is also known as a color map. We briefly used an Albedo map to create a texture previously in the Creating textures with the Image Texture node section of Chapter 2, Introducing Material Nodes.

Any image can be used as an Albedo map, such as a picture of a wooden surface, a painting, or a logo. It is thus completely up to you what image you would like to place in a material. For most purposes, you will probably need to use images of materials; we will learn how to acquire these materials later in Chapter 5, Generating Texture Maps with Cycles.

Figure 4.1 shows a simple Albedo map of a brick texture.

Figure 4.1 – Brick Albedo map

As we have learned previously, in the Creating textures with the Image Texture node section of Chapter 2, albedo maps are loaded into an Image Texture node and plugged...

Introducing Roughness maps

Roughness maps, as the name suggests, are images used to control the level of roughness on different parts of a texture. Lower levels of roughness will lead to a glossier object. Adjusting this property with a roughness map can have a significant impact on the level of realism of a material, as not all parts of a material always have the same level of roughness. Figure 4.4 shows the Roughness map corresponding to the Albedo map from Figure 4.1.

Figure 4.4 – A Roughness map for a brick texture

As you can see, the Roughness map looks just like the Albedo map, except it is black and white. To understand how a roughness map works, let’s view the Roughness slider in the Principled BSDF node, shown in Figure 4.5.

Figure 4.5 – Roughness slider in the Principled BSDF node

To control the roughness of a material, we only need to give Blender a single numerical value between 0.000 and 1...

Using Normal maps to detail surfaces

Normal maps are special texture maps used to simulate surface details and bumps. Their purpose is to increase the level of apparent detail on a texture or object without adding any new geometry. Normal maps, as with other texture maps, can also be applied through Image Texture nodes, but they will require us to change a few extra things to let Blender know that this is a special type of image. Figure 4.11 shows an example of a Normal map.

Figure 4.11 – A simple Normal map

To apply this Normal map, we must first set Color Space to Non-Color in the Image Texture node. Then, we must add a normal map node and plug it into the Normal input of the Principled BSDF node. Blender will now know how to read this image correctly.

Figure 4.12 – Processing a Normal map

If we apply this Normal map to a material, it will simulate bumps on the surface, as shown in Figure 4.13.

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Creating transparency

We will now learn two different ways to create transparency in Blender. First, we will learn how Alpha maps can be used to create transparent areas in a texture, and then we will learn how to create realistic glass in the Cycles render engine. This will allow us to create vegetation, nets, windows, bottles, damaged fabric, and other objects that require some level of transparency.

Understanding Alpha maps

Alpha maps are texture maps used to control the transparency of a material. Alpha is a property of color that measures the degree of opacity, and opacity is the level of visibility of a texture. If an image is transparent, it means that it has no opacity, or that its alpha value is 0. Alpha maps are useful for textures on which some parts are transparent while other parts are non-transparent, such as vegetation or a fishing net texture.

Much like a roughness map uses the brightness of each pixel to determine the roughness value of a texture, an Alpha...

Summary

In this chapter, we learned what texture maps are and how they work, and we explored some of the most commonly used texture maps. We also learned how to create transparency with Alpha maps and by creating glass.

In Chapter 5, Generating Texture Maps with Cycles, we will learn how to create our own texture maps inside Blender, or with the help of some external tools, and apply them to our materials. This will give us the freedom to download any material from the internet and easily bring it into Blender or create our own custom materials and texture maps.