Global Variable

SCNProgramMappingChannelKey

The mapping channel to be used for a texture coordinate semantic.

Declaration

NSString *const SCNProgramMappingChannelKey;

Discussion

This key can be used with the options dictionary for the setSemantic:forSymbol:options: method, and applies only to the SCNGeometrySourceSemanticTexcoord semantic. Its value is an NSNumber object containing an unsigned integer value.

A geometry can provide, and a shader program can use, more than one source of texture coordinates for each vertex. Use this key to specify which geometry source should provide data for each texture sampler vertex attribute declared in a shader program. The mapping channel for a geometry source corresponds to its index in the array returned by calling the geometrySourcesForSemantic: method.

See Also

Mapping GLSL Symbols to SceneKit Semantics

- setSemantic:forSymbol:options:

Associates a SceneKit semantic identifier with the specified GLSL vertex attribute or uniform variable.

- semanticForSymbol:

Returns the SceneKit semantic identifiers associated with the specified GLSL vertex attribute or uniform variable.

SCNModelTransform

A 4 x 4 matrix for transforming coordinates from model space to scene (or world) space.

SCNModelViewProjectionTransform

A 4 x 4 matrix containing the concatenation of the Model, View, and Projection transformations.

SCNModelViewTransform

A 4 x 4 matrix containing the concatenation of the Model and View transformations.

SCNNormalTransform

A 4 x 4 matrix for transforming surface normal vectors from model space to view (or eye) space.

SCNProjectionTransform

A 4 x 4 matrix for transforming coordinates from view (or eye) space to clip space.

SCNViewTransform

A 4 x 4 matrix for transforming coordinates from scene (or world) space to view (or eye) space.