I’m trying to draw large and complex ditches in Sketchup so that I can easily calculate their overall volume. I’m using technical drawings of the ditches to inform my 3D models.
I am trying to use contours to construct the ditches in Sketchup. I first the trace the ditch outline from a ground plan in Adobe Illustrator. This gives me an accurate outline of the footprint of the ditch. Using the offset tool, I take the outline of the ditch and create another edge set inside slightly (say 1m). I then drop this down 5m to give me an angled profile. I repeat this process as many times as is necessary.
Using this technique I can control the profile of the ditch quite accurately, which is important as I’m interested in calculating the volume of the ditch.
Once I’ve constructed my wireframe of the ditch I use either the Sandbox ‘from contours’ tool or the TopoShaper plugin to generate a surface mesh. It’s then quite simple to generate a solid shape from the surface and obtain its volume from the entity info panel.
However I am running into a problem when the surface meshes are generated (see image). Triangular ‘ridges’ are often generated running down the inside of the ditch which looks unsightly and affect the overall voume of the ditch. This happens especially with round-bottomed ditches. I’ve tried using the smooth / soften edges settings to remove them but to no avail. Does anyone have any suggestions?