So you are covering all 4 methods for creating indices into the pools, right?


L. Spiro

Look at any sample that runs over the faces of each mesh.
You have FbxGeometryElement::eByControlPoint or FbxGeometryElement::eByPolygonVertex.
In both cases you have either GetReferenceMode() == FbxLayerElement::eDirect or FbxLayerElement::eIndexToDirect.

This snippet gets the proper normal index (ffvThisVert.u32NormalIndex) under these considerations:

	// Go over each vertex in the face.
	for ( u32 I = 0UL; I < ui32PolyTotal; ++I ) {
		FC_FACE::FC_FACE_VERTEX ffvThisVert;
		u32 u32VertIndex = piFacePool[ui32PolyStart+I];
		ffvThisVert.u32VertexIndex = u32VertIndex;

		if ( m_u32Flags & FC_NORMALS ) {
			ffvThisVert.u32NormalIndex = 0UL;
			const FbxLayerElementNormal * plenNormals = m_pfmMesh->GetLayer( 0 )->GetNormals();
			switch ( plenNormals->GetMappingMode() ) {
				case FbxGeometryElement::eByControlPoint : {
					// The normal index is based on the vertex index.
					if ( plenNormals->GetReferenceMode() == FbxLayerElement::eDirect ) {
						// The normal index is the same as the vertex index.
						ffvThisVert.u32NormalIndex = u32VertIndex;
					}
					else if ( plenNormals->GetReferenceMode() == FbxLayerElement::eIndexToDirect ) {
						// The normal index is found by plugging the vertex index into an array of indices.
						ffvThisVert.u32NormalIndex = plenNormals->GetIndexArray().GetAt( u32VertIndex );
					}
					if ( ffvThisVert.u32NormalIndex >= static_cast<u32>(plenNormals->GetDirectArray().GetCount()) ) {
						std::cout << "Invalid normal index." << std::endl;
					}
					break;
				}
				case FbxGeometryElement::eByPolygonVertex : {
					// The normal index is based off _favAddVert.u32IndexCount, which is
					//	incremented once for each vertex over which we loop.
					if ( plenNormals->GetReferenceMode() == FbxLayerElement::eDirect ) {
						// It is just _favAddVert.u32IndexCount.
						ffvThisVert.u32NormalIndex = _favAddVert.u32IndexCount;
					}
					else if ( plenNormals->GetReferenceMode() == FbxLayerElement::eIndexToDirect ) {
						// The normal index is found by plugging _favAddVert.u32IndexCount into an array of indices.
						ffvThisVert.u32NormalIndex = plenNormals->GetIndexArray().GetAt( _favAddVert.u32IndexCount );
					}
					break;
				}
				default : {
					std::cout << "Unsupported normal mapping mode." << std::endl;
				}
			}
		}

Vertices, vertex, colors, and UV coordinates all work the same way, though you can go over more layers if you want more UV sets (or you can just ignore all but the base layer).


L. Spiro