Overview

Physically Based Rendering (PBR) materials are essential for achieving realistic visuals in 3D environments. PBR relies on specific texture maps that simulate real-world lighting interactions with surfaces, allowing materials to respond naturally under different lighting conditions. This guide covers the steps and textures needed to create PBR materials for use in Sceneri, focusing on four main texture types: Albedo, Roughness, Metallicity, and Normal Map.

Understanding the PBR Workflow

Before creating textures, it’s helpful to understand the basic principles of PBR. PBR materials aim to replicate how surfaces reflect light. These materials use various maps to define properties such as color, reflectivity, and surface detail, which together create a realistic look.

In Sceneri, the following texture maps are supported for PBR materials:

• Albedo (Base Color)
• Roughness
• Metallicity (Metallic)
• Normal Map

Each texture type provides specific data for the material’s interaction with light, allowing the final result to closely resemble real-world materials.

Creating Each Texture Type

Albedo (Base Color)

The Albedo map represents the base color of the material without any lighting or shading information. It does not contain shadows or highlights, as these are simulated by the rendering engine based on the light in the scene.

• Color Information Only: Avoid including baked lighting, shadows, or ambient occlusion in the albedo map.
• Format: 8-bit RGB (PNG or JPEG).
• Best Practices: Keep the albedo map as flat and clean as possible, and ensure that colors are true to the surface type (e.g., brick, wood, metal).

Roughness Map

The Roughness map defines the smoothness or roughness of a surface. It controls how much light scatters when it hits the surface, affecting how reflective the material appears. A higher roughness value makes the surface appear more matte, while a lower roughness value makes it look shinier.

• Values:
  • White (1) represents a rough, matte surface.
  • Black (0) represents a smooth, reflective surface.
• Format: Grayscale, 8-bit (PNG).
• Best Practices: Use a high-resolution map to capture surface variations, and keep roughness values accurate to the material (e.g., metal often has low roughness, while fabric has high roughness).

Metallicity (Metallic)

The Metallicity map indicates whether a surface is metallic or non-metallic (dielectric). This map determines how the surface interacts with light in terms of reflectivity and color absorption.

• Values:
  • White (1) for fully metallic surfaces.
  • Black (0) for non-metallic (dielectric) surfaces.
• Format: Grayscale, 8-bit (PNG).
• Best Practices: Apply full black for non-metallic surfaces (wood, plastic) and white for metals (steel, gold). Mid-gray values are rarely used, as surfaces are generally either metal or not.

Normal Map

The Normal Map simulates fine surface details, such as bumps or dents, without increasing the polygon count. By modifying the way light interacts with the surface, normal maps create the illusion of depth.

• Color Information: The normal map is encoded in RGB, where each channel represents the X, Y, and Z directions for light manipulation.
• Format: RGB, 8-bit (PNG).
• Best Practices: Generate normal maps in a 3D modeling or texturing software (e.g., Blender, Substance Painter) for accuracy. Avoid too much contrast, which can make the surface appear unnaturally bumpy.

Tips for Optimizing PBR Textures

• Channel Packing: Combine roughness, metallic, and ambient occlusion maps into a single texture file if needed, to reduce texture count and memory usage.
• Resolution: Use the appropriate resolution for each map. Normal and roughness maps often benefit from higher resolution, while metallic maps can generally be lower.
• Realistic Values: Stick to realistic values for roughness and metallicity to maintain natural lighting behavior.

By following these steps, you’ll be able to create realistic, physically based materials that enhance the appearance of assets in Sceneri. Properly configured PBR textures will ensure your materials respond naturally to lighting, providing an immersive and visually engaging experience in your scenes.