For example, a house needs to distinguish between windows, roofs and doors, and set different materials
Hi @h2936817294 ,
For b3dm tilesets (using enableModelExperimental: true in the constructor), the _BATCHID attribute semantic becomes fsInput.featureIds.featureId_0 (see the Custom Shader Guide ). This is to match the newer EXT_mesh_features glTF extension draft. (spec currently under revision on this branch).
In the future, we do plan to add binary metadata properties to custom shaders. When that happens, batch table properties would also be included. As of right now, only the batch ID/feature IDs are available in the shader.