This article is for beginners looking to become 3D artists. By the time you finish reading, you will know three ways to color your model, eleven types of texture maps, and six common beginner mistakes. A careful study of the text will take about 10 minutes.
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Texturing is the process of digitally dyeing a 3D model. Textures bring not only colors but may also add roughness details to the surface, set up reflections, and turn a colorless shape into a believable piece.
The texturing process has three key techniques: Procedural Texturing, Photo Projecting, and Painting. These techniques are often combined to achieve visually rich results.
Procedural texturing uses mathematical algorithms to create textures. Instead of designing every pixel or using pre-made textures, designers write algorithms that generate complex patterns. The main benefit of this technique is its ability to create intricate textures that would be extremely time-consuming or impossible to make manually.
For instance, procedural texturing can be used to create realistic damaged textures. Rather than manually creating corrosion and bumps and peeling paint on a metal surface, you can automatically generate these irregularities using algorithms.
Popular software: Substance Designer, Quixel Mixer, Houdini, World Machine
This technique involves projecting a photograph or image onto a 3D model. The photos capture real-world objects' details, colors, and lighting, producing highly realistic textures.
A typical use case of photo projection is creating accurate and realistic textures, especially for natural objects like rocks, trees, and foliage. It can also help recreate a historical monument. Designers would take photos of the object from various angles, capturing weathering and color nuances. However, photo projecting is time-consuming since the artist needs to select and manipulate the photographs.
Painting is about manually painting textures onto a 3D model. The artist can apply brushes and other tools to create various textures and effects, including bumps, scratches, and further surface details.
For example, if an artist creates a character for a video game, they might use painting to give the character unique features, like tattoos or battle scars. However, this technique is labor-intensive, especially for complex models or large environments. It also greatly relies on the skill of the artist.
Popular software: Substance Painter, Photoshop, Blender
Types of Material
While texturing provides visual detail to your model, materials define how the surfaces of these 3D objects interact with light. They determine surface properties such as visible color, roughness, reflectivity, and transparency. There are two major types of materials in computer graphics: basic and PBR (Physically-Based Rendering).
Basic materials, while simple, cannot simulate the physical properties of surfaces. Their functionality is limited to defining parameters such as base color and highlights. These materials have a low impact on system performance and are used mostly in indie or mobile games.
PBR materials have become the industry standard for AAA game development. This approach is more computationally intensive, but you can create more realistic 3D models using it. The texture maps used along with PBR materials often include:
Albedo Map provides the material's basic color, devoid of any lighting information such as shadows or reflections. For example, this could define the flat red of an apple's skin, before adding any shine or texture.
Normal Map generates an illusion of intricate surface detail on a 3D model without increasing the polygon count. This could simulate the bumpy texture of an orange's skin on a perfectly spherical 3D model. We have already been told how to create a normal map in the previous part of that guide.
Roughness Map informs the light scattering or reflection on the material's surface. For instance, it can differentiate between the smooth, shiny surface of a polished wooden table and the rough, matte surface of an unpolished one.
Gloss Map determines the shine or glossiness of a surface. It is somewhat similar to the roughness map but inverted, and the choice between the two often comes down to software compatibility or specific technical requirements.
Metallic Map identifies the metallic and non-metallic portions of an object. Using a grayscale representation, it can specify the metal trims on a leather-bound book, where white indicates metallic and black indicates non-metallic surfaces.
Emission map makes a 3D object appear as though giving off light. It can create effects like glowing buttons on a control panel. The emissive map controls both the color and intensity of the glow.
Specular Map controls the reflectivity and shininess of a surface. It defines the color and intensity of reflected light on a surface. This texture map is less commonly used in PBR workflows as the metallic and roughness maps often determine specularity.
Height Map adds more significant, visual depth and detail to the 3D object's surface. This map contains data that displaces the geometry of an object, effectively creating height variance.
Opacity map regulates the transparency levels of a 3D object, allowing you to create materials that range from fully opaque to completely transparent. This can make the window glass appear transparent while its wooden frame remains opaque.
Ambient Occlusion Map identifies areas on a model that receive less ambient lighting, providing shading information. This texture map can enhance the sense of depth and volume in the creases of a crumpled piece of paper.
Refraction map modify the angle at which light hits the surface. Often used to simulate the bending of rays as they pass through transparent objects, like making the water in a pool appear to warp the tiles beneath it.
3D MODEL IN ZBRUSH
Understand the essentials of character design in just a week. Explore the interface, learn to sculpt, streamline your work, and start the journey as a 3D Artist.
Painting is a highly intuitive technique for learning texturing. In major productions, 3D artists may use specialized software such as Substance Designer for texturing models. However, Blender is often the preferred tool due to its comprehensive features and the ease with which you can tweak your model if needed.
Finally, let's dive right into it!
Step 1: Setup Texture Painting Workspace
Open your 3D model along with its UV map in Blender, switch to the Texture Paint workspace.
Observe that the workspace divides into two sections: The UV/Image Editor on the left and the 3D Viewport on the right.
If the 3D Viewport appears pink, no texture has been applied. To ensure you see the actual colors, change the viewport shading in the 3D Viewport to “Flat”.
Step 2: Create a New Material and Texture
In the “Properties” panel, go to the “Material” tab and create a new material if your model doesn't have one.
In the “Texture” tab, click on the “+” icon to add a new texture.
Set the type to “Image Texture” and choose a base color.
To add additional maps such as metallic, roughness, bump, or displacement, you will need to create new image textures for each one and then connect them to the corresponding inputs on the Principled BSDF shader in the node editor.
Define the image size: a common setting is 2K (2048x2048), but 4K can be used for higher resolution.
Uncheck the “Alpha” option, unless transparency is required for your texture.
Step 3: Adjust Painting Settings
As you paint, observe that the brush might not affect sharp edges. To change this, go to the tool settings and disable the “Normal” option under the “Falloff” settings.
Ensure your texture is selected in the UV/Image Editor by clicking the image icon.
Adjust brush size by pressing the [F] key and moving your mouse. Control the strength with [Shift + F]. Access the color picker by pressing [S].
Step 4: Configure Bleed Value and Start Filling Colors
Before painting in details, configure the bleed value to 16 pixels for a 2K texture to avoid artifacts. This value determines how far the paint extends beyond the UV borders, which can help prevent seams.
Start filling in colors by selecting parts of the object in edit mode using face select.
After selecting the desired parts, create a paint mask based on these faces and fill them with colors.
Step 5: Detailing and Fine-tuning
Use your references to implement colors and details accurately.
Work on adding shadows, highlights, and textures by manipulating the brush settings. Use the line brush tool for straight lines.
If available, use a drawing tablet for more precise control.
Step 6: Review and Save
Switch to the Rendered view in the 3D Viewport to see how your texture looks when rendered.
Make any necessary adjustments to the texture or material settings based on how it looks in the render.
Rotate and review your model to ensure all areas are covered and appear as desired.
Save your texture image by going to the UV/Image Editor, clicking the Image icon and “Save As”. It's usually best to save your image as a .png because it supports full alpha transparency and lossless compression.
Remember to save your Blender file regularly to avoid losing any progress, and definitely save once you're done.
Poor UV Unwrapping
A flawed UV map can lead to stretching, distortion, and other unwanted artifacts. Dedicate time to efficiently unwrap your model, considering the areas that need more detail and ensuring that the texture coordinates align properly with the 3D geometry.
Incorrect Texture Resolution
Using textures with inadequate resolution can cause pixelation and a lack of detail, while excessively high resolution may unnecessarily waste system resources. Find the right balance considering the target platform.
Neglecting Texture Seams
When texturing a 3D model, you will often have to deal with seams, the edges where different texture parts meet. If not handled carefully, these seams can be harsh. Google techniques such as seam hiding, blending, or using procedural textures to hide the seams.
Not Gathering Enough References
If you don't have a material science degree, you won't be able to think up a texture. Collecting reference images is crucial to create a proper surface of the objects you're trying to replicate. If you have any difficulties, we’ve collected 115 resources with references and divided them into categories.
Lack of Attention to Detail
The devil's in the detail. Even PBR materials won't make your model look realistic without working on nuances. Take the time to add those little imperfections and variations that make textures more believable.
Textures always interact with the lighting in your scene. Experiment with different light sources and settings to see how they influence the appearance of the object's surface and set the proper parameters.
Once the textures are created, you can showcase the 3D model in your portfolio or integrate it into a game engine. Popular solutions Unity or Unreal Engine provide material editors, so you can assign textures to materials and tweak their properties such as roughness, metallic, or transparency.
Wow, you've reached the end of this guide! With a general understanding of the modeling pipeline, it'll be easy for you to hone your skills in our courses on ZBrush and Blender under the guidance of experienced instructors from CD Project Red and Void Interactive.
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