Function ProcessMesh

Source/Engine/Tools/ModelTool/ModelTool.Assimp.cpp:241–441

}

bool ProcessMesh(ModelData& result, AssimpImporterData& data, const aiMesh* aMesh, MeshData& mesh, String& errorMsg)
{
    // Properties
    mesh.Name = aMesh->mName.C_Str();
    mesh.MaterialSlotIndex = aMesh->mMaterialIndex;

    // Vertex positions
    mesh.Positions.Set((const Float3*)aMesh->mVertices, aMesh->mNumVertices);

    // Texture coordinates
    for (int32 channelIndex = 0; channelIndex < MODEL_MAX_UV && aMesh->mTextureCoords[channelIndex]; channelIndex++)
    {
        mesh.UVs.Resize(channelIndex + 1);
        auto& channel = mesh.UVs[channelIndex];
        channel.Resize(aMesh->mNumVertices, false);
        aiVector3D* a = aMesh->mTextureCoords[channelIndex];
        for (uint32 v = 0; v < aMesh->mNumVertices; v++)
        {
            channel.Get()[v] = *(Float2*)a;
            a++;
        }
    }

    // Indices
    const int32 indicesCount = aMesh->mNumFaces * 3;
    mesh.Indices.Resize(indicesCount, false);
    for (unsigned faceIndex = 0, i = 0; faceIndex < aMesh->mNumFaces; faceIndex++)
    {
        const auto face = &aMesh->mFaces[faceIndex];
        if (face->mNumIndices != 3)
        {
            errorMsg = TEXT("All faces in a mesh must be triangles!");
            return true;
        }

        mesh.Indices[i++] = face->mIndices[0];
        mesh.Indices[i++] = face->mIndices[1];
        mesh.Indices[i++] = face->mIndices[2];
    }

    // Normals
    if (data.Options.CalculateNormals || !aMesh->mNormals)
    {
        // Support generation of normals when using assimp.
        if (mesh.GenerateNormals(data.Options.SmoothingNormalsAngle))
        {
            errorMsg = TEXT("Failed to generate normals.");
            return true;
        }
    }
    else if (aMesh->mNormals)
    {
        mesh.Normals.Set((const Float3*)aMesh->mNormals, aMesh->mNumVertices);
    }

    // Tangents
    if (aMesh->mTangents)
    {