On my current project, a test file, set to a probably ridiculously high quality setting resulted in: Geometries in cache: 1639 Geometry cache size in bytes: 208982480 CGAL Polyhedrons in cache: 407 CGAL cache size in bytes: 0 Total rendering time: 0:00:58.677    Top level object is a 3D object (manifold):    Status:     NoError    Genus:      -1    Vertices:    14910    Facets:      29812 Reducing the number of lines (9 down from 90, with fa = 2 and fs = 0.125) used to describe a quarter arc resulted in instead: Compiling design (CSG Tree generation)... Rendering Polygon Mesh using Manifold... Geometries in cache: 613 Geometry cache size in bytes: 33362992 CGAL Polyhedrons in cache: 87 CGAL cache size in bytes: 0 Total rendering time: 0:00:01.471    Top level object is a 3D object (manifold):    Status:     NoError    Genus:      -1    Vertices:     8004    Facets:      16000 The file is just 4 dozen or so toolpaths --- before reducing the quality the file was getting quite bogged down, and the fans on my computer came on (which they rarely do) --- what are the upper limits for these numbers? How far below those limits do I need to stay to keep compile times down to something reasonable? (multiple seconds okay, but minutes don't seem reasonable to expect folks to wait) Over 200 MB seems a bit much to represent a 400 x 200 x 6mm piece of stock which has only been cut away at a few times... What is a reasonable memory usage for a 3D model for reasonable performance? (Or is that not a determinant? Which number should be looked at as a cautionary guide?) William -- Sphinx of black quartz, judge my vow. https://designinto3d.com/

There is no answer to this. It depends on your RAM and what operations you have. Are you using Minkowski? Otherwise, it is weird for Manifold to be this slow with just 2 times the number of faces. On Wed, Jul 2, 2025 at 11:44 AM William F. Adams via Discuss < discuss@lists.openscad.org> wrote: > On my current project, a test file, set to a probably ridiculously high > quality setting resulted in: > > Geometries in cache: 1639 > Geometry cache size in bytes: 208982480 > CGAL Polyhedrons in cache: 407 > CGAL cache size in bytes: 0 > Total rendering time: 0:00:58.677 > Top level object is a 3D object (manifold): > Status: NoError > Genus: -1 > Vertices: 14910 > Facets: 29812 > > > Reducing the number of lines (9 down from 90, with fa = 2 and fs = 0.125) > used to describe a quarter arc resulted in instead: > > Compiling design (CSG Tree generation)... > Rendering Polygon Mesh using Manifold... > Geometries in cache: 613 > Geometry cache size in bytes: 33362992 > CGAL Polyhedrons in cache: 87 > CGAL cache size in bytes: 0 > Total rendering time: 0:00:01.471 > Top level object is a 3D object (manifold): > Status: NoError > Genus: -1 > Vertices: 8004 > Facets: 16000 > > > The file is just 4 dozen or so toolpaths --- before reducing the quality > the file was getting quite bogged down, and the fans on my computer came on > (which they rarely do) --- what are the upper limits for these numbers? How > far below those limits do I need to stay to keep compile times down to > something reasonable? (multiple seconds okay, but minutes don't seem > reasonable to expect folks to wait) > > Over 200 MB seems a bit much to represent a 400 x 200 x 6mm piece of stock > which has only been cut away at a few times... > > What is a reasonable memory usage for a 3D model for reasonable > performance? (Or is that not a determinant? Which number should be looked > at as a cautionary guide?) > > William > > -- > Sphinx of black quartz, judge my vow. > https://designinto3d.com/ > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >

On Wednesday, July 2, 2025 at 02:38:13 AM EDT, pca006132 <john.lck40@gmail.com> wrote: >There is no answer to this. It depends on your RAM and what operations you have. I know it depends, I was hoping for some guidelines/sharing of experiences. At what numbers do folks find that their projects become a problem and need to be simplified/have triangles reduced? >Are you using Minkowski? Otherwise, it is weird for Manifold to be this slow with just 2 times the number of faces. No, I'm simulating a cutting tool using a library I've been working on for a while: https://github.com/WillAdams/gcodepreview I now have it re-structured so that it should allow usage on arbitrarily large files (previously, it was limited by the depth of the CSG tree (or CGS?!? that's what one window says) but I've now got things flattened out), so I'm trying to give performance and so forth a consideration. William -- Sphinx of black quartz, judge my vow. https://designinto3d.com/