{ "__type": "IngestedDoc", "__tag": 4010, "_content": { "Notes": { "__type": "Section", "__tag": 4015, "children": [ { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "The algorithm " }, { "__type": "FootnoteReference", "__tag": 4066, "label": "1" }, { "__type": "Text", "__tag": 4046, "value": " is an improved version of Chernyaev's Marching Cubes 33 algorithm. It is an efficient algorithm that relies on heavy use of lookup tables to handle the many different cases, keeping the algorithm relatively easy. This implementation is written in Cython, ported from Lewiner's C++ implementation." } ] }, { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "To quantify the area of an isosurface generated by this algorithm, pass verts and faces to " }, { "__type": "CrossRef", "__tag": 4002, "value": "skimage.measure.mesh_surface_area", "reference": { "__type": "RefInfo", "__tag": 4000, "module": "skimage", "version": "*", "kind": "api", "path": "skimage.measure._marching_cubes_lewiner:mesh_surface_area" }, "kind": "module" }, { "__type": "Text", "__tag": 4046, "value": "." } ] }, { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "Regarding visualization of algorithm output, to contour a volume named " }, { "__type": "InlineRole", "__tag": 4003, "value": "myvolume", "domain": null, "role": null, "inventory": null }, { "__type": "Text", "__tag": 4046, "value": " about the level 0.0, using the " }, { "__type": "InlineCode", "__tag": 4051, "value": "mayavi" }, { "__type": "Text", "__tag": 4046, "value": " package " } ] }, { "__type": "Code", "__tag": 4050, "value": ">>>\n>> from mayavi import mlab\n>> verts, faces, _, _ = marching_cubes(myvolume, 0.0)\n>> mlab.triangular_mesh([vert[0] for vert in verts],\n [vert[1] for vert in verts],\n [vert[2] for vert in verts],\n faces)\n>> mlab.show()", "execution_status": null }, { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "Similarly using the " }, { "__type": "InlineCode", "__tag": 4051, "value": "visvis" }, { "__type": "Text", "__tag": 4046, "value": " package " } ] }, { "__type": "Code", "__tag": 4050, "value": ">>>\n>> import visvis as vv\n>> verts, faces, normals, values = marching_cubes(myvolume, 0.0)\n>> vv.mesh(np.fliplr(verts), faces, normals, values)\n>> vv.use().Run()", "execution_status": null }, { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "To reduce the number of triangles in the mesh for better performance, see this " }, { "__type": "Link", "__tag": 4049, "children": [ { "__type": "Text", "__tag": 4046, "value": "example" } ], "url": "https://docs.enthought.com/mayavi/mayavi/auto/example_julia_set_decimation.html#example-julia-set-decimation", "title": "" }, { "__type": "Text", "__tag": 4046, "value": " using the " }, { "__type": "InlineCode", "__tag": 4051, "value": "mayavi" }, { "__type": "Text", "__tag": 4046, "value": " package." } ] } ], "title": [], "level": 0, "target": null }, "Warns": { "__type": "Section", "__tag": 4015, "children": [], "title": [], "level": 0, "target": null }, "Raises": { "__type": "Section", "__tag": 4015, "children": [], "title": [], "level": 0, "target": null }, "Yields": { "__type": "Section", "__tag": 4015, "children": [], "title": [], "level": 0, "target": null }, "Methods": { "__type": "Section", "__tag": 4015, "children": [], "title": [], "level": 0, "target": null }, "Returns": { "__type": "Section", "__tag": 4015, "children": [ { "__type": "Parameters", "__tag": 4026, "children": [ { "__type": "DocParam", "__tag": 4016, "name": "verts", "annotation": "(V, 3) array", "desc": [ { "__type": "Paragraph", "__tag": 4045, "children": [ { "__type": "Text", "__tag": 4046, "value": "Spatial coordinates for V unique mesh vertices. 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[1] Thomas Lewiner, Helio Lopes, Antonio Wilson Vieira and Geovan", " Tavares. Efficient implementation of Marching Cubes' cases with", " topological guarantees. Journal of Graphics Tools 8(2)", " pp. 1-15 (december 2003).", " :DOI:`10.1080/10867651.2003.10487582`", ".. [2] Lorensen, William and Harvey E. Cline. Marching Cubes: A High", " Resolution 3D Surface Construction Algorithm. Computer Graphics", " (SIGGRAPH 87 Proceedings) 21(4) July 1987, p. 163-170).", " :DOI:`10.1145/37401.37422`" ], "qa": "skimage.measure._marching_cubes_lewiner:marching_cubes", "arbitrary": [], "local_refs": [ "allow_degenerate", "faces", "gradient_direction", "level", "mask", "method", "normals", "spacing", "step_size", "values", "verts", "volume" ] }