private void ConstructFaceNormal(MeshGeometry3D themesh, int faceindex)
{
Point3D centroid = Tools3D.ComputeTriangleCentroid(themesh, faceindex);
Vector3D facenormal = Tools3D.ComputeTriangleNormal(themesh, faceindex);
ConstructAnnotationArrow(centroid, facenormal, CONTAINERfacenormals);
}
private void ConstructVertexNormalsMatchingFaceNormal(MeshGeometry3D themesh, int faceindex)
{
Vector3D facenormal = Tools3D.ComputeTriangleNormal(themesh, faceindex);
ConstructAnnotationArrow(themesh.Positions[themesh.TriangleIndices[faceindex * 3]], facenormal, CONTAINERfacenormals);
ConstructAnnotationArrow(themesh.Positions[themesh.TriangleIndices[faceindex * 3 + 1]], facenormal, CONTAINERfacenormals);
ConstructAnnotationArrow(themesh.Positions[themesh.TriangleIndices[faceindex * 3 + 2]], facenormal, CONTAINERfacenormals);
}
private void ConstructVertexNormalsForTwoFaceSituation(MeshGeometry3D themesh)
{
Vector3D facenormal0 = Tools3D.ComputeTriangleNormal(themesh, 0);
Vector3D facenormal1 = Tools3D.ComputeTriangleNormal(themesh, 1);
// The edge vertices (non-shared) use the face normal as-is
ConstructAnnotationArrow(themesh.Positions[1], facenormal0, CONTAINERfacenormals);
ConstructAnnotationArrow(themesh.Positions[3], facenormal1, CONTAINERfacenormals);
// The shared vertices 0 and 2 use the average of the two normals.
Vector3D normalavgd = (facenormal0 + facenormal1);
normalavgd.Normalize();
ConstructAnnotationArrow(themesh.Positions[0], normalavgd, CONTAINERfacenormals);
ConstructAnnotationArrow(themesh.Positions[2], normalavgd, CONTAINERfacenormals);
}