IDirect3DRMMeshBuilder::GenerateNormals

HRESULT GenerateNormals();

Processes the Direct3DRMMeshBuilder object and generates vertex normals that are the average of each vertex's adjoining face normals.

·Returns D3DRM_OK if successful, or an error otherwise. For a list of possible return codes, see Direct3D Retained-Mode Return Values.

Averaging the normals of back-to-back faces produces a zero normal.