Global Variable

SCNGeometrySourceSemanticTangent

The semantic for surface tangent vector data.

Declaration

const SCNGeometrySourceSemantic SCNGeometrySourceSemanticTangent;

Discussion

For a geometry source, this semantic identifies data containing the surface tangent vector at each vertex in the geometry. SceneKit uses this information to compute advanced lighting effects on the surface.

For a custom shader program, you use this semantic to bind SceneKit’s vertex tangent data to an input attribute of the shader.

Vertex tangent data is typically an array of three- or four-component vectors.

See Also

Advanced Shading Semantics

SCNGeometrySourceSemanticColor

The semantic for per-vertex color data.