displacementmaps

Displacement maps are textures used to modify the geometry of a surface by displacing its vertices along the surface normal according to the value stored in the map. The map is typically a grayscale image where lighter values push the surface outward and darker values pull it inward. In some cases, color channels may encode multi-dimensional displacement.

Displacement can be applied in two main ways: true displacement, where the geometry is actually displaced, often via tessellation or a displacement shader; and pseudo-displacement (such as parallax or relief mapping) where shading is adjusted to simulate depth without altering geometry. True displacement increases mesh density to preserve silhouette and shading accuracy, while pseudo-displacement only affects the shading and can be cheaper to render.

Displacement maps are commonly stored as height maps, but more complex workflows may use vector displacement maps that encode displacement in multiple axes using RGB channels or dedicated channels. Formats include 8- or 16-bit grayscale images and higher-dynamic-range textures such as EXR. The displacement values are typically scaled by a user-defined factor to suit the scene.

Advantages of displacement maps include adding fine geometric detail without manually modeling high-poly geometry and achieving correct self-occlusion, shadows, and silhouettes. Limitations include higher processing and memory requirements, potential artifacts at seams or sharp edges, and the need for compatible rendering pipelines that support tessellation or displacement shading. Real-time engines may offer limited support or reduced quality.

Applications span visual effects, game development, architectural visualization, and product rendering. Workflows often involve baking detail from high-poly models into displacement textures and tuning tessellation and sampling settings to balance quality and performance.