# "Sweeping" a geometry from point A to point B

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## "Sweeping" a geometry from point A to point B

 This is probably the most unusual problem you guys ever heard of, so I'll not be surprised if there is no solution for it available with any combination of tools in CGAL. Remember when you had Windows 98 and the screen would freeze up with an error shown in a dialog popup? Remember moving this dialog box around and its canvas leaving a drawing "trail", as if it was some sort of a slug? I'm trying to recreate exactly that effect, but with a 3d object. Imagine you have a not-so-primitive shape, like a 3D cross, and you want to drag it around in a 3d space, in the 3 axis, leaving a trail behind. The final geometry ends up being this snake-like geometry based on the initial 3D cross. As if you moved a clone of the cross just a fraction of a millimeter, made an union boolean, and repeated until you have the desired result. How would you do it? Considering that a boolean would take hours of processing. -- Sent from: http://cgal-discuss.949826.n4.nabble.com/-- You are currently subscribed to cgal-discuss. To unsubscribe or access the archives, go to https://sympa.inria.fr/sympa/info/cgal-discuss
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## Re: "Sweeping" a geometry from point A to point B

 Do you want a continuous translation or a discrete one along a polyline? Is your input mesh close or open? If the mesh is open and you consider discrete translation, you might be able to use extrude_mesh() for each segment: https://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__meshing__grp.html#ga102e1ba5d709c5e53e013160792e4d08and compute the union of all segments using corefine_and_compute_union(): https://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__corefinement__grp.html#gad7e1741a7ce41a5846cf86494982ca8bSebastien. On 10/9/19 3:09 PM, aseverino wrote: > This is probably the most unusual problem you guys ever heard of, so I'll not > be surprised if there is no solution for it available with any combination > of tools in CGAL. > > Remember when you had Windows 98 and the screen would freeze up with an > error shown in a dialog popup? Remember moving this dialog box around and > its canvas leaving a drawing "trail", as if it was some sort of a slug? > > I'm trying to recreate exactly that effect, but with a 3d object. > > Imagine you have a not-so-primitive shape, like a 3D cross, and you want to > drag it around in a 3d space, in the 3 axis, leaving a trail behind. The > final geometry ends up being this snake-like geometry based on the initial > 3D cross. As if you moved a clone of the cross just a fraction of a > millimeter, made an union boolean, and repeated until you have the desired > result. > > How would you do it? Considering that a boolean would take hours of > processing. > > > > -- > Sent from: http://cgal-discuss.949826.n4.nabble.com/> -- You are currently subscribed to cgal-discuss. To unsubscribe or access the archives, go to https://sympa.inria.fr/sympa/info/cgal-discuss
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## Re: "Sweeping" a geometry from point A to point B

 Sorry that I wasn't specific enough. I always forget to include some important information.Unfortunately, it has to be both continuous along a "curved" high-res polyline, and the mesh is closed.On Wed, Oct 9, 2019 at 12:33 PM Sebastien Loriot (GeometryFactory) <[hidden email]> wrote:Do you want a continuous translation or a discrete one along a polyline? Is your input mesh close or open? If the mesh is open and you consider discrete translation, you might be able to use extrude_mesh() for each segment: https://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__meshing__grp.html#ga102e1ba5d709c5e53e013160792e4d08 and compute the union of all segments using corefine_and_compute_union(): https://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__corefinement__grp.html#gad7e1741a7ce41a5846cf86494982ca8b Sebastien. On 10/9/19 3:09 PM, aseverino wrote: > This is probably the most unusual problem you guys ever heard of, so I'll not > be surprised if there is no solution for it available with any combination > of tools in CGAL. > > Remember when you had Windows 98 and the screen would freeze up with an > error shown in a dialog popup? Remember moving this dialog box around and > its canvas leaving a drawing "trail", as if it was some sort of a slug? > > I'm trying to recreate exactly that effect, but with a 3d object. > > Imagine you have a not-so-primitive shape, like a 3D cross, and you want to > drag it around in a 3d space, in the 3 axis, leaving a trail behind. The > final geometry ends up being this snake-like geometry based on the initial > 3D cross. As if you moved a clone of the cross just a fraction of a > millimeter, made an union boolean, and repeated until you have the desired > result. > > How would you do it? Considering that a boolean would take hours of > processing. > > > > -- > Sent from: http://cgal-discuss.949826.n4.nabble.com/ > -- You are currently subscribed to cgal-discuss. To unsubscribe or access the archives, go to https://sympa.inria.fr/sympa/info/cgal-discuss -- Alexandre A. SeverinoSystems Developer and Analyst+55 11 99994-9148Si quieres cambio verdadero, pues camina distinto!