Hi I am try to draw a series on polylines on a surface. I am evaluating the curves to place my points in order to create polylines. The problem is that it can only analyze curves and place points move in one direction only. I cannot analyze a curve and move points on opposite side… Is there a series of commands that can fix this. Attached in definition with geometry internalized. I only evaluated the curves where it works. It would be helpful if you can provide guidance on same curves. Attached definition with internalized geometry. Also there is screen shot showing my problem and screen shot showing goal. Thanks!

062521_Evaluate Curve Doesn’t Allow me to analyze inverse location.gh (44.2 KB)

I would do that with Vectors instead of Evaluate Curve, but mine is just a personal preference

062521_Evaluate Curve Doesn’t Allow me to analyze inverse location_Re.gh (52.3 KB)

Thank you for your solution that is an interesting approach. I actually used evaluate surface to draw my lines based on the plan of each geometry.