You CAN use the triangulate2D. 1 ) pipe your points into a POINT SOP and set $TZ to 0 2 ) your points are now on a 2D plane, so you can use the triangulate2D SOP 3 ) pipe the result into another POINT SOP ( input 1 ) 4 ) pipe your original points into the second input of the POINT SOP ( input 2 ) 5 ) replace $TZ with $TZ2 ( that put the TZ data back ) 6 ) job done. Hope that helps, Julien