should the first break point be 5.51,0,5.51? Your input gives the break at 7.7405,0,7.7405 for me
That's the difference between 2006 and 2010 & up, Relative and absolute coordinates on input from the keyboard.
Can you provide a complete working script? This content based on your posts does break the 3DPOLY but it breaks it at the wrong elevation. Please provide a full script to demonstrate breaking it at elevation 5.51.
My fault, gentlemen, I wish to apologize for that, 'cause the point 10,0,5.51 does not belong to the line 0,0,0-10,0,10 indeed.
I don't see an easy solution, I mean without using trigonometry.
On the other hand, the _SLICE command (by Z=5.51 plane) works only with solids, not with simple lines.
Sorry for my answer, I thought that Antonio has the right solution !?
Maybe I have a "stupid/bad" solution which needs a few commands !
So a Lisp/VLisp programm will be very useful ...
Draw a SOLID (Box in fact) : Height = 5.51 - which "includes the line" ...
Explode the SOLID, so you get 3DFaces ...
Draw a Line from (.xy) at beginning (Snap=END) of your line (0,0,0)
when asking for Z; click with (Snap=NEA) at the Face (which is at Z=5.51)
then draw the line with Ortho ...
I think that the Intersection of your first line and "my" line is the point you were looking for !?
If you were to consider third party software, MapWorks Base contains two tools to handle this. First is 3dPoly Mark Elevations which marks all points of a specified elevation along a selection set of 3dPolylines. Second (and most important in this case) is 3dPoly Break At Elevation which breaks a selected 3dPoly at a specified elevation along a segment (also preserves Extended Entity Data on the newly created polyline).