For a footwear project we are working on we need to make a watertight seal to two different trimmed polygon naked edges loops. There’s no possibility to match the edge count on these since they come from completely different definitions/processes and they are trimmed by an aleatory 3D curve that does not look into poly flow at all, by design.
When ne have ‘matched polyline/polygon naked-edge count’ we can use the Mesh loft component from Chromodoris plugin:
But we don’t have a way to make a polygons loft (or bridge) of mismatched point-count polylines.
Here’s an example of what I created by shattering 2 polylines into 10 segments so lofts do not get unmanageabe and twisty:
I manually created the polygons in one section of the shattered curves, and added random color to each polygon for visual clarity.
We need to create polygons ONLY using the existing polylines as input, no adding any extra vertices, otherwise the mesh-Join will not be watertight. for analysis and RP.
A possible logic needed I think it would be:
which ones of these two shattered polylines has smallest point count? (in this case is the upper curve in Z direction, called point 1)
Starting with smallest point-count curve, make a quad polygon between: (point 1 or polyline 1), point 2 on polyline 1, closets point of polyline 2 to (point 2 of polyline1), closets point of curve 2 to (point 2 on curve 1)
This keeps going until there are quad polygons fill the entire upper polyline chain:
Then fill with triangles all the gaps in the lower curve.
BTW, this is very similar to what the Bridge too in Modo would do:
So basically we need a bridge tool in Grasshopper. We have very many applications for this tool besides this RP watertight hack use-case.
Here’s the grasshopper file with internalized polylines and sample manual mesh:
making_polygon_bridge_with_mismatched_count_polylines_01_gf_190402.gh (30.5 KB)
In general we need to have a bunch of SubD modeling tools in GH, and I really really hope this is coming and soon, because the workflows that this allows are absolutely amazing.
In the meantime if anyone has any ideas of how to achieve this in GH Iwe’d really appreciate it.