This page contains reference documentation for the DisplayFaceNormals member. This member sets or gets whether or not the mesh renders face normals.
int DisplayFaceNormals;
Examples are as follows:
ParametricMesh editMesh = new ParametricMesh; editMesh.DisplayFaceNormals = 1; editMesh.DisplayFaceNormals = !editMesh.DisplayFaceNormals;
For sample code: