public static float GetFaceArea(this ITVFace face, IList <IPoint3> verts)
{
// get all vert indices from this face
int[] arrVertIndices = face.GetAllVerts();
// get the IPoints from the vertlist
// since all max sdk interface are using the IDisposable interface
// you have to call dispose, they will be not handled by the garbage collection
using (IPoint3 v0 = verts[arrVertIndices[0]])
using (IPoint3 v1 = verts[arrVertIndices[1]])
using (IPoint3 v2 = verts[arrVertIndices[2]])
{
// build the edge vestors and return the result
using (IPoint3 v1v0 = v1.Subtract(v0))
using (IPoint3 v2v1 = v2.Subtract(v1))
return(v1v0.CrossProduct(v2v1).GetFaceArea());
}
}
/// <summary>
/// get the face area for a face
/// </summary>
/// <param name="face"></param>
/// <param name="verts"></param>
/// <returns></returns>
public static IPoint3 GetFaceNormal(this IFace face, IList <IPoint3> verts)
{
// get all vert indices from this face
int[] arrVertIndices = face.GetAllVerts();
// get the IPoints from the vertlist
// since all max sdk interface are using the IDisposable interface
// you have to call dispose, they will be not handled by the garbage collection
using (IPoint3 v0 = verts[arrVertIndices[0]])
using (IPoint3 v1 = verts[arrVertIndices[1]])
using (IPoint3 v2 = verts[arrVertIndices[2]])
{
// build the edge vestors
using (IPoint3 v1v0 = v1.Subtract(v0))
using (IPoint3 v2v1 = v2.Subtract(v1))
{
// the cross product of the edge vector is the face normal ( unnormalized )
// the length of the face normal is twice the face area
return(v1v0.CrossProduct(v2v1));
}
}
}
