Drawing basic lines

[LandSurvey]

I have periodically had this problem. I draw a line connecting two nodes. Then when I try to draw a seperate line perpendicular to the previous line, it does not go perpendicular. Then if I try to join the 2 lines as a polyline, I get an error message telling me that they are not coplanar. I can fix this problem by doing flatten Z values on the line drawn between the 2 nodes. It's as if the lines can't really touch each other because they are on different planes? Does anyone know why this happens and how I can fix the entire drawing instead of haveing to fix each individual line? Thanks, Land Survey

 

[CarlAK]

When you snap to a node, the line takes on the z value of the node. When you draw perpendicular to this line, it draws it perpendicular in 3d which is not perp in 2d.

To "fix" it you could set all the "nodes" to zero before drawing lines. Or you'll have to fix lines after you draw them. To fix a lot of lines all at one time, use the "flatten" Express Tool or lisp routine of same name. You can use flatten on the nodes. Be careful flattening nodes, you may want the z value for other purposes.