Normal Mapping

Normal Mapping perturbs the lit surface normal per pixel without adding geometry, so a flat plane can read as cracked stone or hammered metal. Genesis supports the standard URP tangent-space inputs and adds strength scaling, a secondary detail layer, and per-channel masking.

When to use it

Almost every Lit material — cheap shape definition without polygons.
Hero props that need close-up bump detail.
Stylized characters where a soft normal adds form without breaking the cel banding.
Terrain and rocks — usually paired with Triplanar Mapping.

Difference from Detail Textures

Normal Mapping is a single map sampled at the base UV. Detail Textures lets you add a second normal at independent tiling — typically 5–20x — for the micro-bump that hides macro-tiling.

How it works

Genesis samples _BumpMap, unpacks it from DXT5nm or BC5 to a tangent-space normal, scales the X and Y components by _BumpScale, and transforms the result into world space using the mesh’s TBN matrix. The world normal then drives every other lighting term — diffuse, specular, rim, MatCap, and SSS.

Properties

Inspector label	Shader property	Type	Default	Description
Normal Map	_BumpMap	Texture2D	bump	Tangent-space normal map. Import as Normal Map.
Normal Strength	_BumpScale	Float (0–2)	1.0	Multiplier on the XY components. 0 = flat, 2 = exaggerated.
Detail Normal	_DetailNormalMap	Texture2D	None	Optional secondary normal at detail tiling.
Detail Strength	_DetailNormalScale	Float (0–2)	1.0	Strength of the detail layer.
Detail Tiling	_DetailNormalTiling	Vector4	(8,8,0,0)	Tiling (xy) and offset (zw) for the detail UV.
Normal Mask	_NormalMask	Texture2D	white	Greyscale mask restricting bump to regions.

Usage

Author the normal in Substance, Blender, or xNormal and import it as a Normal Map in Unity.
Assign it to the Normal Map slot. A strength of 1 matches the source; push to 1.5 for stylized exaggeration.
For close-up shots, add a high-frequency Detail Normal at 5–10x tiling.
Use a packed mask to restrict bump to specific regions — none on a smooth visor, full on the body.


material.SetTexture("_BumpMap", normalTex);
material.SetFloat("_BumpScale", 1.2f);
material.SetTextureScale("_DetailNormalMap", new Vector2(10, 10));

Tips & gotchas

Always set the import type to Normal Map, or Unity will not pack to DXT5nm and the green channel will look wrong.
BC5 is preferred for high-strength normals; DXT5nm shows banding past a strength of 1.3.
Procedural meshes need tangents — call mesh.RecalculateTangents() or import tangents from the FBX.
A single normal sample is cheap; the detail normal doubles the cost, so measure before shipping.

Detail Textures — secondary albedo and normal at independent tiling.
Triplanar Mapping — normal-friendly UV-free projection.
Translucency & SSS — driven by the same world normal.
MatCap — normal influence on MatCap UVs.