Hi,
I’m working with a list of polylines in Dynamo and would like to connect them in a way that allows me to calculate a common bounding box. What would be the best approach or logic to use for connecting these polylines in Dynamo? My goal is to determine the height and width of the common inclusion shape. Any advice or ideas on how to tackle this in Dynamo would be greatly appreciated!
I think you want the smallest rectangle around the objects, but if you want a rectangle that is aligned to the XY axis instead you can swap step 5 below for a Geometry.BoundingBox node.
- Select the objects somehow. There are many ways in Dynamo for Civil 3D to do this.
- Pull the geometry into Dynamo as a PolyCurve, likely via Object.Geometry, but some object types won’t work that way in some builds so the specific implementation will be on you to work out in your environment.
- Extrude the PolyCurves into surface using a Curve.Extrude method that allows a vector as the extrusion control, passing a Vector.ZAxis node into the vector input. This should produce a set of surfaces 1 unit tall, with a base that aligns to the original polycurves.
- Use a PolySurface.ByJoinedSurfaces node to union them into a single geomtry. Note that this node processes the polysurface even if the source surfaces don’t touch.
- Use a BoundingBox.ByMinimumVolume node to get the smallest box that fits the polycurves.
- Convert the bounding box to a cuboid with a BoundingBox.ToCuboid.
- Extract the base of the cuboid by exploding it into a set of faces, and pull the bottom face (vector points down or lowest Z value of the midpoint of each surface).
- Pull the perimeter curves of that face and merge into a single polyline. This geometry can then be sent to AutoCAD or you can leverage it’s component parts to generate CAD elements.
Note that if your original polycurves aren’t 2D flat you might not get good results by extruding vertically, or you may need to pull things onto a common plane at some point.
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The PolySurface.ByJoinedSurfaces makes only one big surface, I don’t understand.
Correct - this is to get the rectangle around all of the polylines - are you looking for the rectangle around each polyline?
I need these boundingboxes.
I used Geometry.Intersect to find which rectangles are close to each other and merge the individual faces of those rectangles that are connected. I got the common bounding boxes at the end.
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