private Boolean ExtractMeshData(Scene scene, ref List <H1MeshContext> meshContexts)
{
Int32 currMeshContextIndex = 0;
foreach (Mesh mesh in scene.Meshes) // process each mesh in the scene
{
H1MeshContext currMeshContext = new H1MeshContext();
// set mesh name
currMeshContext.Name = mesh.Name;
// get the offset matrix
Matrix globalOffsetMtx = GetOffsetMatrix(scene, currMeshContextIndex);
// store LocalToTransform for later usage (converting offset matrix space to root node space)
Vector3 translation;
SharpDX.Quaternion rotation;
Vector3 scaling;
globalOffsetMtx.Decompose(out scaling, out rotation, out translation);
currMeshContext.LocalToGlobalTransform.Scaling = scaling;
currMeshContext.LocalToGlobalTransform.Rotation = rotation;
currMeshContext.LocalToGlobalTransform.Translation = translation;
// if mesh doesn't follow the rule below, do not process mesh in Assimp
if (mesh.HasVertices &&
mesh.HasNormals &&
mesh.HasTangentBasis &&
mesh.TextureCoordinateChannels[0].Count > 0 &&
mesh.HasFaces) // process vertices in the mesh
{
int vertexCount = mesh.VertexCount;
foreach (Vector3D vertex in mesh.Vertices)
{
Vector3 convertedVertex = new Vector3(vertex.X, vertex.Y, vertex.Z);
// transform with the 'offsetMtx'
Vector4 result = Vector3.Transform(convertedVertex, globalOffsetMtx);
// divide by w for homogeneous vector
result /= result.W;
convertedVertex.X = result.X;
convertedVertex.Y = result.Y;
convertedVertex.Z = result.Z;
currMeshContext.Positions.Add(convertedVertex);
}
foreach (Vector3D normal in mesh.Normals)
{
// @TODO - need to transform space appropriately (normal transform is applied by different algorithm! - scaling!)
Vector3 convertedNormal = new Vector3(normal.X, normal.Y, normal.Z);
currMeshContext.Normals.Add(convertedNormal);
}
foreach (Vector3D biTangent in mesh.BiTangents)
{
// @TODO - need to transform this appropriately
Vector3 convertedBiTangent = new Vector3(biTangent.X, biTangent.Y, biTangent.Z);
currMeshContext.BiTangents.Add(convertedBiTangent);
}
foreach (Vector3D tangent in mesh.Tangents)
{
// @TODO - need to transform this appropriately
Vector3 convertedTangent = new Vector3(tangent.X, tangent.Y, tangent.Z);
currMeshContext.Tangents.Add(convertedTangent);
}
// only handling one texture coordinates (first one and only UV type (not UVW type)), currently
if (mesh.UVComponentCount[0] == 3) // if UVW type
{
throw new Exception("invalid UV component type (UVW), please check!");
}
List <Vector2> Tecoord2Ds = currMeshContext.AddTexcoord2DBufferContext();
foreach (Vector3D texCoord in mesh.TextureCoordinateChannels[0])
{
Vector2 convertedTexCoord = new Vector2(texCoord.X, texCoord.Y);
Tecoord2Ds.Add(convertedTexCoord);
}
foreach (Face face in mesh.Faces)
{
if (face.IndexCount != 3)
{
// @TODO - split polygon to triangles!
continue;
//throw new Exception("invalid index count, it is over 3, please check!");
}
foreach (UInt32 index in face.Indices)
{
currMeshContext.Indices.Add(index);
}
}
meshContexts.Add(currMeshContext);
}
currMeshContextIndex++;
}
return(true);
}
