Mapping image
Overview
The Mapping image is a structure that maps each point on a geometry to a point on another geometry. The LOD processors in Simplygon generate mapping images between the original models and their LODs to be able to cast all the original materials and properties to the corresponding point on the generated mesh.
The Surface Mapper can create mapping images between any two meshes.
The mapping image is a texture generated for the LOD during the processing. It uses the LOD's newly generated texture coordinates. Per pixel it contains the original triangle ID and the barycentric coordinate of the corresponding point on the original object's surface. The mapping image is needed to automatically cast materials with any of the material casters (color caster, normal caster etc.). But the user can also use it manually to retrieve any information from the original model for the current surface element on the LOD.
Components
Mapping image consists of the following components:
Parameterizer
To create the new and unique texture coordinates.Chart aggregator
To create the texture coordinates based on the original texture coordinates.Material caster
Is given the mapping image to cast the materials.Vertex color baker
Is given the mapping image to bake the vertex colors.