Measure perpendicular distance between 2 polylines

[fieldguy]

I need the perpendicular distance between 2 polylines.  If I was doing this manually, I would draw a line perp from 1 side and extend it to the other side, check it's length, and delete it.  These are pipeline r/w's that quite often have variable width, and are not always parallel.

I am asking the user to select the pline 1st (GetEntity) to get some object data.  Then I prompt for a point on the pline where a block will be placed. The block contains an attribute definition for the width.  I check to make sure the point is on the pline.  I was hoping I could get the user to select a point on the opposite side and force that to be perp.  That would give me the width but it doesn't work.  I have looked at GetFirstDerivative and rotate that 90 but the examples I found use a certain length.  The perp length is what I need to determine.  I need some hints please!

[g_k50]

The distance between P(x1, y1, z1) and P2(x2, y2, z2) is equal to the square root of [(x2-x1)^2 + (y2-y1)^2 + (z2-z1)^2)]

[_gile]

Hi,

Look at the Curve.GetClosestPointTo() method.

Select a polyline (pl1) and a point on the other one (pt on pl2), then:

pt.DistanceTo(pl1.GetclosestPointTo (pt, false));

The distance is measured perpendicular to pl2 (and pl1 if they're parralel).