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- From: Johnny Bigert <>
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- Subject: [cgal-discuss] Calculate polygons of projection
- Date: Thu, 30 Jun 2022 12:51:55 +0200
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Hi,
I would like to kindly ask for ideas regarding a problem I'm trying to solve.
I have a triangulated shape as a Polyhedron_3 with exact constructions. The shape is closed and simple and may contain holes.
What I would like to calculate is most easily described like this (and takes an input parameter z): if we cut away parts of the shape from Z = minus infinity to Z = z, what would the shadow (projection) of the shape look like if we shine a flashlight from above, from Z = plus infinity.
The result will consist of multiple polygons since the shadow might have disjoint areas (e.g. candelabra) and holes (e.g. drinking glass).
Do you have any ideas how to implement this efficiently? Sweep line algorithms? Ray casting? Thanks!
Best regards, Johnny
- [cgal-discuss] Calculate polygons of projection, Johnny Bigert, 06/30/2022
- Re: [cgal-discuss] Calculate polygons of projection, Sebastien Loriot, 06/30/2022
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