// OnPolymesh is called when a tessellated polymesh of a 3D face is being output.
// The current material is applied to the polymesh.
public void OnPolymesh(
PolymeshTopology InPolymeshNode // tessellated polymesh output node
)
{
if (IgnoreElementGeometry())
{
return;
}
// Retrieve the Datasmith mesh being processed.
FDatasmithFacadeMesh CurrentMesh = GetCurrentMesh();
Transform MeshPointsTransform = GetCurrentMeshPointsTransform();
// Retrieve the index of the current material and make the Datasmith mesh keep track of it.
int CurrentMaterialIndex = GetCurrentMaterialIndex();
int initialVertexCount = CurrentMesh.GetVertexCount();
// Add the vertex points (in right-handed Z-up coordinates) to the Datasmith mesh.
foreach (XYZ Point in InPolymeshNode.GetPoints())
{
XYZ FinalPoint = MeshPointsTransform != null?MeshPointsTransform.OfPoint(Point) : Point;
CurrentMesh.AddVertex((float)FinalPoint.X, (float)FinalPoint.Y, (float)FinalPoint.Z);
}
// Add the vertex UV texture coordinates to the Datasmith mesh.
foreach (UV uv in InPolymeshNode.GetUVs())
{
CurrentMesh.AddUV(0, (float)uv.U, (float)-uv.V);
}
IList <PolymeshFacet> Facets = InPolymeshNode.GetFacets();
// Add the triangle vertex indexes to the Datasmith mesh.
foreach (PolymeshFacet facet in Facets)
{
CurrentMesh.AddTriangle(initialVertexCount + facet.V1, initialVertexCount + facet.V2, initialVertexCount + facet.V3, CurrentMaterialIndex);
}
// Add the triangle vertex normals (in right-handed Z-up coordinates) to the Datasmith mesh.
// Normals can be associated with either points or facets of the polymesh.
switch (InPolymeshNode.DistributionOfNormals)
{
case DistributionOfNormals.AtEachPoint:
{
IList <XYZ> normals = InPolymeshNode.GetNormals();
if (MeshPointsTransform != null)
{
foreach (PolymeshFacet facet in Facets)
{
XYZ normal1 = MeshPointsTransform.OfVector(normals[facet.V1]);
XYZ normal2 = MeshPointsTransform.OfVector(normals[facet.V2]);
XYZ normal3 = MeshPointsTransform.OfVector(normals[facet.V3]);
CurrentMesh.AddNormal((float)normal1.X, (float)normal1.Y, (float)normal1.Z);
CurrentMesh.AddNormal((float)normal2.X, (float)normal2.Y, (float)normal2.Z);
CurrentMesh.AddNormal((float)normal3.X, (float)normal3.Y, (float)normal3.Z);
}
}
else
{
foreach (PolymeshFacet facet in Facets)
{
XYZ normal1 = normals[facet.V1];
XYZ normal2 = normals[facet.V2];
XYZ normal3 = normals[facet.V3];
CurrentMesh.AddNormal((float)normal1.X, (float)normal1.Y, (float)normal1.Z);
CurrentMesh.AddNormal((float)normal2.X, (float)normal2.Y, (float)normal2.Z);
CurrentMesh.AddNormal((float)normal3.X, (float)normal3.Y, (float)normal3.Z);
}
}
break;
}
case DistributionOfNormals.OnePerFace:
{
XYZ normal = InPolymeshNode.GetNormals()[0];
if (MeshPointsTransform != null)
{
normal = MeshPointsTransform.OfVector(normal);
}
for (int i = 0; i < 3 * InPolymeshNode.NumberOfFacets; i++)
{
CurrentMesh.AddNormal((float)normal.X, (float)normal.Y, (float)normal.Z);
}
break;
}
case DistributionOfNormals.OnEachFacet:
{
if (MeshPointsTransform != null)
{
foreach (XYZ normal in InPolymeshNode.GetNormals())
{
XYZ FinalNormal = MeshPointsTransform.OfVector(normal);
CurrentMesh.AddNormal((float)FinalNormal.X, (float)FinalNormal.Y, (float)FinalNormal.Z);
CurrentMesh.AddNormal((float)FinalNormal.X, (float)FinalNormal.Y, (float)FinalNormal.Z);
CurrentMesh.AddNormal((float)FinalNormal.X, (float)FinalNormal.Y, (float)FinalNormal.Z);
}
}
else
{
foreach (XYZ normal in InPolymeshNode.GetNormals())
{
CurrentMesh.AddNormal((float)normal.X, (float)normal.Y, (float)normal.Z);
CurrentMesh.AddNormal((float)normal.X, (float)normal.Y, (float)normal.Z);
CurrentMesh.AddNormal((float)normal.X, (float)normal.Y, (float)normal.Z);
}
}
break;
}
}
}
private static void AddNormalsToMesh(FDatasmithFacadeMesh Mesh, Vector3f NormalA, Vector3f NormalB, Vector3f NormalC)
{
Mesh.AddNormal(NormalA.X, NormalA.Y, NormalA.Z);
Mesh.AddNormal(NormalB.X, NormalB.Y, NormalB.Z);
Mesh.AddNormal(NormalC.X, NormalC.Y, NormalC.Z);
}
