Lazy union problem

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Lazy union problem

jamcultur
I tried the lazy-union option in 2020.11.30.ci6340 (git 9a08c222f) using code
that imports a DXF and extrudes it along a Bezier curve. For this test, I
used a DXF with a complex curve and extruded along a cubic Bezier curve. In
2019.05 it took 12 minutes, 43 seconds to render. In 2020.11.30 without lazy
union, it took 13:14. In 2020.11.30 with lazy union, it took much longer,
20:14, and gave a warning message. The STL file generated with lazy union
was more than twice the size of the STL file without lazy union. (Both were
much smaller than the STL file generated by 2019.05, which I assume is
because of the difference between ascii and binary STL files.) I checked the
STLs using Meshmixer. The one generated without lazy union was perfect. The
one generated with lazy union had many errors in the mesh. Do I need to
change something in my code to get lazy union to work properly? Here is the
render output with lazy union:

Rendering Polygon Mesh using CGAL...
WARNING: GeometryEvaluator: Node didn't fit into cache. location unknown
Geometries in cache: 301
Geometry cache size in bytes: 52139248
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Total rendering time: 0:20:14.228
   Top level object is a list of objects:
   Objects:    2
Rendering finished.

Here is the output without lazy union:

Rendering Polygon Mesh using CGAL...
Geometries in cache: 302
Geometry cache size in bytes: 52139248
CGAL Polyhedrons in cache: 1
CGAL cache size in bytes: 93641336
Total rendering time: 0:13:14.294
   Top level object is a 3D object:
   Simple:        yes
   Vertices:    37621
   Halfedges:  218446
   Edges:      109223
   Halffacets: 143210
   Facets:      71605
   Volumes:         2
Rendering finished.



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Re: Lazy union problem

nophead
I think you would need to add an explicit union where you want a manifold that can be exported in STL. STL cannot handle overlapping solids.

On Sat, 5 Dec 2020 at 18:08, jamcultur <[hidden email]> wrote:
I tried the lazy-union option in 2020.11.30.ci6340 (git 9a08c222f) using code
that imports a DXF and extrudes it along a Bezier curve. For this test, I
used a DXF with a complex curve and extruded along a cubic Bezier curve. In
2019.05 it took 12 minutes, 43 seconds to render. In 2020.11.30 without lazy
union, it took 13:14. In 2020.11.30 with lazy union, it took much longer,
20:14, and gave a warning message. The STL file generated with lazy union
was more than twice the size of the STL file without lazy union. (Both were
much smaller than the STL file generated by 2019.05, which I assume is
because of the difference between ascii and binary STL files.) I checked the
STLs using Meshmixer. The one generated without lazy union was perfect. The
one generated with lazy union had many errors in the mesh. Do I need to
change something in my code to get lazy union to work properly? Here is the
render output with lazy union:

Rendering Polygon Mesh using CGAL...
WARNING: GeometryEvaluator: Node didn't fit into cache. location unknown
Geometries in cache: 301
Geometry cache size in bytes: 52139248
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Total rendering time: 0:20:14.228
   Top level object is a list of objects:
   Objects:    2
Rendering finished.

Here is the output without lazy union:

Rendering Polygon Mesh using CGAL...
Geometries in cache: 302
Geometry cache size in bytes: 52139248
CGAL Polyhedrons in cache: 1
CGAL cache size in bytes: 93641336
Total rendering time: 0:13:14.294
   Top level object is a 3D object:
   Simple:        yes
   Vertices:    37621
   Halfedges:  218446
   Edges:      109223
   Halffacets: 143210
   Facets:      71605
   Volumes:         2
Rendering finished.



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