When working with surfaces, it can be useful to determine where a vector intersects with a surface, which you can do with the surface’s IntersectPointWithSurface() method. For example, you can determine if the top of a structure is visible from a point on the surface, or whether one point on the surface is visible from another point. This example tests whether a vector starting at (20424.7541, 20518.0409, 100) pointing in direction (0.6, 0.4, -0.5) intersects with the first surface in the drawing, and if it does, it prints out the intersection location:
Dim objSurf As AeccSurface Dim varStartPt As Variant, varDir As Variant, varIntPt As Variant Dim darrStart(2) As Double Dim darrDir(2) As Double darrStart(0) = 20424.7541 darrStart(1) = 20518.0409 darrStart(2) = 100 darrDir(0) = 0.6 darrDir(1) = 0.4 darrDir(2) = -0.5 varStartPt = darrStart varDir = darrDir Set objSurf = g_oAeccDoc.Surfaces(0) varIntPt = objSurf.IntersectPointWithSurface(varStartPt, varDir) If UBound(varIntPt) = 2 Then Debug.Print varIntPt(0), varIntPt(1), varIntPt(2) End If