Method MeshGeometry

code/AssetLib/FBX/FBXMeshGeometry.cpp:94–186

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// ------------------------------------------------------------------------------------------------
MeshGeometry::MeshGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc)
: Geometry(id, element,name, doc)
{
    const Scope* sc = element.Compound();
    if (!sc) {
        DOMError("failed to read Geometry object (class: Mesh), no data scope found");
    }

    // must have Mesh elements:
    const Element& Vertices = GetRequiredElement(*sc,"Vertices",&element);
    const Element& PolygonVertexIndex = GetRequiredElement(*sc,"PolygonVertexIndex",&element);

    // optional Mesh elements:
    const ElementCollection& Layer = sc->GetCollection("Layer");

    std::vector<aiVector3D> tempVerts;
    ParseVectorDataArray(tempVerts,Vertices);

    if(tempVerts.empty()) {
        FBXImporter::LogWarn("encountered mesh with no vertices");
    }

    std::vector<int> tempFaces;
    ParseVectorDataArray(tempFaces,PolygonVertexIndex);

    if(tempFaces.empty()) {
        FBXImporter::LogWarn("encountered mesh with no faces");
    }

    m_vertices.reserve(tempFaces.size());
    m_faces.reserve(tempFaces.size() / 3);

    m_mapping_offsets.resize(tempVerts.size());
    m_mapping_counts.resize(tempVerts.size(),0);
    m_mappings.resize(tempFaces.size());

    const size_t vertex_count = tempVerts.size();

    // generate output vertices, computing an adjacency table to
    // preserve the mapping from fbx indices to *this* indexing.
    unsigned int count = 0;
    for(int index : tempFaces) {
        const int absi = index < 0 ? (-index - 1) : index;
        if(static_cast<size_t>(absi) >= vertex_count) {
            DOMError("polygon vertex index out of range",&PolygonVertexIndex);
        }

        m_vertices.push_back(tempVerts[absi]);
        ++count;

        ++m_mapping_counts[absi];

        if (index < 0) {
            m_faces.push_back(count);
            count = 0;
        }
    }