forge-normal-maps

To add tangent-space normal mapping to an SDL GPU project, extend the vertex format with a vec4 tangent, construct a TBN matrix in the vertex shader, and sample a normal map in the fragment shader to perturb lighting per texel.

Tangent-space normal mapping is used to increase per-pixel surface detail on textured 3D meshes without adding extra geometry. It enables richer visuals by simulating fine surface details like bumps and grooves during fragment lighting.

Yes, you can apply normal mapping to models lacking tangents by optionally computing the tangent data on import. This allows you to extend meshes without pre-existing tangent vectors to support the TBN construction workflow.

You construct a TBN matrix in a vertex shader by using the vertex normal and a vec4 tangent from the extended vertex layout. This matrix transforms normal-map samples into the correct surface space for fragment lighting.

Tangent-space normal mapping requires a vertex layout extension to include a vec4 tangent attribute. The fragment shader workflow also needs two textures and appropriate bindings to decode the normal map and apply surface lighting.