I'm trying to do a macro to draw curved ribbed pipes and to do this, I need to know positions at regular intervals along the length of a bezier curve. The idea is that the user clicks on a bezier curve, then clicks on a half ellipse (the rib). The macro then copies the half ellipse along the bezier curve at regular intervals, at the correct angle for the curve at each point, giving the impression of a ribbed pipe.
Of course I need to know the angle of the bezier line at each point so I'd know what angle to change the rib to
First I thought I'd be able to split the bezier into a set number of segments and use end point details for each segment, but I can't find a way to do this.
I'm thinking it will have to be maths, but I don't know if there is a formula that mere mortals could understand for working out points along a bezier. Does anyone know?
The image below illustrates what I'm trying to do. The 'rib' at one end of the bezier wants copying along it's length (at points highlighted by the circles), and its angle changing to suit.