I’m attempting to come up with a way to accurately model roadways based on civil engineering construction data. I’ve managed to use two curves (one defining the top-view road centerline, the other applied as a bevel object defining the cross section of the roadway) which gives fine results that are an approximation of the real roadway. But I need to be able to enter the actual design geometry to get accurate results.
First, I need to be able to get the top-view (plan) centerline of the roadway into Blender from CAD. I haven’t tried bringing it in as a path yet, but I assume this is the way to do it. Anyone have a suggestion as to the best format? (eps, ai, etc)
Next, I need to get the vertical (profile) of the road into Blender. In my approximations discussed above, I’ve just tweaked the Z-values of the 3D roadway curve. But actual roadway designs use vertical profiles with parabolic curves defined by three parameters: 1) calling out a specific point along the alignment (the Station), 2) the point of intersection (P.I.) of the in-coming and out-going tangents of the vertical curve, and 3) the elevation of that point of intersection.
Using a 3D Bezier curve to define the roadway centerline doesn’t seem to be the answer, since the actual roadway geometry for the top view and profile view would need to have control points at different locations.
My guess is that I’ll need to define the top-view with a Bezier curve and then somehow break subdivide that curve into a large number of small segments. After this is done, each of the small segments will have their control points adjusted vertically to their proper elevation based on the geometric profile definition.
I know this is a bit technical, but I’m hoping somebody has already tackled it. In order to help with my explanations, here is a link to a roadway Plan and Profile construction sheet showing what the profile geometry looks like:
Thanks in advance for any and all suggestions!