I’ve been developing a Dynamo workflow to automate basin stage–storage calculations directly from Civil 3D surfaces to remove manual steps and make basin analysis fully dynamic.
Workflow overview:
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Inputs – Select the basin boundary polyline and TIN surface, then define Min/Max RL and increment.
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Crop surface – Limit the surface to the basin area (currently facing an issue here).
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Generate Z levels – Create elevation stages between the min and max levels.
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Calculate areas – Intersect each plane with the surface to determine plan area.
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Compute volumes – Apply trapezoidal calculations for incremental and cumulative storage.
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Export – Output the full stage–storage table to Excel.
The challenge is that the Civil3DToolkit.TinSurface.ByCroppingBoundary node used to clip a surface to a polygon is no longer available in the latest Dynamo library. Without it, isolating the basin area isn’t working properly, leading to inaccurate volume results.
I could create cropped surfaces manually in Civil 3D, but I’d prefer to keep this fully dynamic by allowing automatic cropping from selected polygons within the script. Has anyone found a good workaround or replacement node for surface clipping in recent Dynamo builds?
Thanks
