From 48314f5cdba0e1da7575540ac31ec68cc78adf92 Mon Sep 17 00:00:00 2001 From: Adrian Mariano Date: Sun, 17 Oct 2021 17:40:47 -0400 Subject: [PATCH] vnf doc tweaks and cleanup remove vnf args for chaining vnf_merge pass through if you give just one vnf vnf_vertex_array no longer calls merge vnf_tri_array removes degenerate faces and no longer calls merge (with cleanup) --- vnf.scad | 175 +++++++++++++++++++++++++++++-------------------------- 1 file changed, 93 insertions(+), 82 deletions(-) diff --git a/vnf.scad b/vnf.scad index ec94018..95bafff 100644 --- a/vnf.scad +++ b/vnf.scad @@ -16,17 +16,17 @@ // You can construct a `polyhedron()` in parts by describing each part in a self-contained VNF, then // merge the various VNFs to get the completed polyhedron vertex list and faces. -// Constant: EMPTY_VNF -// Description: -// The empty VNF data structure. Equal to `[[],[]]`. +/// Constant: EMPTY_VNF +/// Description: +/// The empty VNF data structure. Equal to `[[],[]]`. EMPTY_VNF = [[],[]]; // The standard empty VNF with no vertices or faces. // Function: vnf_vertex_array() // Usage: -// vnf = vnf_vertex_array(points, [caps], [cap1], [cap2], [style], [reverse], [col_wrap], [row_wrap], [vnf]); +// vnf = vnf_vertex_array(points, [caps], [cap1], [cap2], [style], [reverse], [col_wrap], [row_wrap]); // Description: -// Creates a VNF structure from a vertex list, by dividing the vertices into columns and rows, +// Creates a VNF structure from a rectangular vertex list, by dividing the vertices into columns and rows, // adding faces to tile the surface. You can optionally have faces added to wrap the last column // back to the first column, or wrap the last row to the first. Endcaps can be added to either // the first and/or last rows. The style parameter determines how the quadrilaterals are divided into @@ -34,17 +34,18 @@ EMPTY_VNF = [[],[]]; // The standard empty VNF with no vertices or faces. // is the uniform subdivision in the other (alternate) direction. The "min_edge" style picks the shorter edge to // subdivide for each quadrilateral, so the division may not be uniform across the shape. The "quincunx" style // adds a vertex in the center of each quadrilateral and creates four triangles, and the "convex" and "concave" styles -// chooses the locally convex/concave subdivision. +// chooses the locally convex/concave subdivision. Degenerate faces +// are not included in the output, but if this results in unused vertices they will still appear in the output. // Arguments: // points = A list of vertices to divide into columns and rows. +// --- // caps = If true, add endcap faces to the first AND last rows. // cap1 = If true, add an endcap face to the first row. // cap2 = If true, add an endcap face to the last row. // col_wrap = If true, add faces to connect the last column to the first. // row_wrap = If true, add faces to connect the last row to the first. // reverse = If true, reverse all face normals. -// style = The style of subdividing the quads into faces. Valid options are "default", "alt", "min_edge", "quincunx","convex" and "concave". -// vnf = If given, add all the vertices and faces to this existing VNF structure. +// style = The style of subdividing the quads into faces. Valid options are "default", "alt", "min_edge", "quincunx", "convex" and "concave". // Example(3D): // vnf = vnf_vertex_array( // points=[ @@ -104,12 +105,12 @@ function vnf_vertex_array( col_wrap=false, row_wrap=false, reverse=false, - style="default", - vnf=EMPTY_VNF + style="default" ) = assert(!(any([caps,cap1,cap2]) && !col_wrap), "col_wrap must be true if caps are requested") assert(!(any([caps,cap1,cap2]) && row_wrap), "Cannot combine caps with row_wrap") assert(in_list(style,["default","alt","quincunx", "convex","concave", "min_edge"])) + assert(is_matrix(points[0], n=3),"Point array has the wrong shape or points are not 3d") assert(is_consistent(points), "Non-rectangular or invalid point array") let( pts = flatten(points), @@ -117,7 +118,7 @@ function vnf_vertex_array( rows = len(points), cols = len(points[0]) ) - rows<=1 || cols<=1 ? vnf : + rows<=1 || cols<=1 ? EMPTY_VNF : let( cap1 = first_defined([cap1,caps,false]), cap2 = first_defined([cap2,caps,false]), @@ -134,66 +135,61 @@ function vnf_vertex_array( i4 = ((r+0)%rows)*cols + ((c+1)%cols) ) mean([pts[i1], pts[i2], pts[i3], pts[i4]]) + ], + allfaces = [ + if (cap1) count(cols,reverse=!reverse), + if (cap2) count(cols,(rows-1)*cols, reverse=reverse), + for (r = [0:1:rowcnt-1], c=[0:1:colcnt-1]) + each + let( + i1 = ((r+0)%rows)*cols + ((c+0)%cols), + i2 = ((r+1)%rows)*cols + ((c+0)%cols), + i3 = ((r+1)%rows)*cols + ((c+1)%cols), + i4 = ((r+0)%rows)*cols + ((c+1)%cols), + faces = + style=="quincunx"? + let(i5 = pcnt + r*colcnt + c) + [[i1,i5,i2],[i2,i5,i3],[i3,i5,i4],[i4,i5,i1]] + : style=="alt"? + [[i1,i4,i2],[i2,i4,i3]] + : style=="min_edge"? + let( + d42=norm(pts[i4]-pts[i2]), + d13=norm(pts[i1]-pts[i3]), + shortedge = d42<=d13 ? [[i1,i4,i2],[i2,i4,i3]] + : [[i1,i3,i2],[i1,i4,i3]] + ) + shortedge + : style=="convex"? + let( // Find normal for 3 of the points. Is the other point above or below? + n = (reverse?-1:1)*cross(pts[i2]-pts[i1],pts[i3]-pts[i1]), + convexfaces = n==0 ? [[i1,i4,i3]] + : n*pts[i4] > n*pts[i1] ? [[i1,i4,i2],[i2,i4,i3]] + : [[i1,i3,i2],[i1,i4,i3]] + ) + convexfaces + : style=="concave"? + let( // Find normal for 3 of the points. Is the other point above or below? + n = (reverse?-1:1)*cross(pts[i2]-pts[i1],pts[i3]-pts[i1]), + concavefaces = n==0 ? [[i1,i4,i3]] + : n*pts[i4] <= n*pts[i1] ? [[i1,i4,i2],[i2,i4,i3]] + : [[i1,i3,i2],[i1,i4,i3]] + ) + concavefaces + : [[i1,i3,i2],[i1,i4,i3]], + // remove degenerate faces + culled_faces= [for(face=faces) + if (norm(verts[face[0]]-verts[face[1]])>EPSILON && + norm(verts[face[1]]-verts[face[2]])>EPSILON && + norm(verts[face[2]]-verts[face[0]])>EPSILON) + face + ], + rfaces = reverse? [for (face=culled_faces) reverse(face)] : culled_faces + ) + rfaces, ] ) - vnf_merge(cleanup=false, [ - vnf, - [ - verts, - [ - for (r = [0:1:rowcnt-1], c=[0:1:colcnt-1]) - each - let( - i1 = ((r+0)%rows)*cols + ((c+0)%cols), - i2 = ((r+1)%rows)*cols + ((c+0)%cols), - i3 = ((r+1)%rows)*cols + ((c+1)%cols), - i4 = ((r+0)%rows)*cols + ((c+1)%cols), - faces = - style=="quincunx"? - let(i5 = pcnt + r*colcnt + c) - [[i1,i5,i2],[i2,i5,i3],[i3,i5,i4],[i4,i5,i1]] - : style=="alt"? - [[i1,i4,i2],[i2,i4,i3]] - : style=="min_edge"? - let( - d42=norm(pts[i4]-pts[i2]), - d13=norm(pts[i1]-pts[i3]), - shortedge = d42<=d13 ? [[i1,i4,i2],[i2,i4,i3]] - : [[i1,i3,i2],[i1,i4,i3]] - ) - shortedge - : style=="convex"? - let( // Find normal for 3 of the points. Is the other point above or below? - n = (reverse?-1:1)*cross(pts[i2]-pts[i1],pts[i3]-pts[i1]), - convexfaces = n==0 ? [[i1,i4,i3]] - : n*pts[i4] > n*pts[i1] ? [[i1,i4,i2],[i2,i4,i3]] - : [[i1,i3,i2],[i1,i4,i3]] - ) - convexfaces - : style=="concave"? - let( // Find normal for 3 of the points. Is the other point above or below? - n = (reverse?-1:1)*cross(pts[i2]-pts[i1],pts[i3]-pts[i1]), - concavefaces = n==0 ? [[i1,i4,i3]] - : n*pts[i4] <= n*pts[i1] ? [[i1,i4,i2],[i2,i4,i3]] - : [[i1,i3,i2],[i1,i4,i3]] - ) - concavefaces - : [[i1,i3,i2],[i1,i4,i3]], - // remove degenerate faces - culled_faces= [for(face=faces) - if (norm(verts[face[0]]-verts[face[1]])>EPSILON && - norm(verts[face[1]]-verts[face[2]])>EPSILON && - norm(verts[face[2]]-verts[face[0]])>EPSILON) - face - ], - rfaces = reverse? [for (face=culled_faces) reverse(face)] : culled_faces - ) - rfaces, - if (cap1) count(cols,reverse=!reverse), - if (cap2) count(cols,(rows-1)*cols, reverse=reverse) - ] - ] - ]); + [verts,allfaces]; // Function: vnf_tri_array() @@ -202,7 +198,8 @@ function vnf_vertex_array( // Description: // Produces a vnf from an array of points where each row length can differ from the adjacent rows by up to 2 in length. This enables // the construction of triangular VNF patches. The resulting VNF can be wrapped along the rows by setting `row_wrap` to true. -// You cannot wrap columns: if you need to do that you'll need to combine two VNF arrays that share edges. +// You cannot wrap columns: if you need to do that you'll need to combine two VNF arrays that share edges. Degenerate faces +// are not included in the output, but if this results in unused vertices they will still appear in the output. // Arguments: // points = List of point lists for each row // row_wrap = If true then add faces connecting the first row and last row. These rows must differ by at most 2 in length. @@ -237,8 +234,8 @@ function vnf_vertex_array( // vnf = vnf_tri_array(pts); // vnf_wireframe(vnf,width=0.1); // color("red")move_copies(flatten(pts)) sphere(r=.15,$fn=9); -function vnf_tri_array(points, row_wrap=false, reverse=false, vnf=EMPTY_VNF) = - let( +function vnf_tri_array(points, row_wrap=false, reverse=false) = + let( lens = [for(row=points) len(row)], rowstarts = [0,each cumsum(lens)], faces = @@ -273,8 +270,17 @@ function vnf_tri_array(points, row_wrap=false, reverse=false, vnf=EMPTY_VNF) = for(j=[count:1:select(lens,i+1)]) reverse ? [ j+nextrow-1, j+rowstart+1, j+rowstart]: [ j+nextrow-1, j+rowstart, j+rowstart+1], ] : assert(false,str("Unsupported row length difference of ",delta, " between row ",i," and ",(i+1)%len(points))) - ]) - vnf_merge(cleanup=true, [vnf, [flatten(points), faces]]); + ], + verts = flatten(points), + culled_faces= + [for(face=faces) + if (norm(verts[face[0]]-verts[face[1]])>EPSILON && + norm(verts[face[1]]-verts[face[2]])>EPSILON && + norm(verts[face[2]]-verts[face[0]])>EPSILON) + face + ] + ) + [flatten(points), culled_faces]; @@ -292,7 +298,9 @@ function vnf_tri_array(points, row_wrap=false, reverse=false, vnf=EMPTY_VNF) = // eps = the tolerance in finding duplicates when cleanup=true. Default: EPSILON function vnf_merge(vnfs, cleanup=false, eps=EPSILON) = is_vnf(vnfs) ? vnf_merge([vnfs], cleanup, eps) : - assert( is_vnf_list(vnfs) , "Improper vnf or vnf list")   + assert( is_vnf_list(vnfs) , "Improper vnf or vnf list") + len(vnfs)==1 ? (cleanup ? _vnf_cleanup(vnfs[0][0],vnfs[0][1],eps) : vnfs[0]) + : let ( offs = cumsum([ 0, for (vnf = vnfs) len(vnf[0]) ]), verts = [for (vnf=vnfs) each vnf[0]], @@ -307,7 +315,11 @@ function vnf_merge(vnfs, cleanup=false, eps=EPSILON) = offs[i] + j ] ] ) - ! cleanup ? [verts, faces] : + cleanup? _vnf_cleanup(verts,faces,eps) : [verts,faces]; + + + +function _vnf_cleanup(verts,faces,eps) = let( dedup = vector_search(verts,eps,verts), // collect vertex duplicates map = [for(i=idx(verts)) min(dedup[i]) ], // remap duplic vertices @@ -405,7 +417,7 @@ function _cleave_connected_region(region) = // Function: vnf_from_region() // Usage: -// vnf = vnf_from_region(region, [transform], [reverse], [vnf]); +// vnf = vnf_from_region(region, [transform], [reverse]); // Description: // Given a (two-dimensional) region, applies the given transformation matrix to it and makes a (three-dimensional) triangulated VNF of // faces for that region, reversed if desired. @@ -413,7 +425,6 @@ function _cleave_connected_region(region) = // region = The region to conver to a vnf. // transform = If given, a transformation matrix to apply to the faces generated from the region. Default: No transformation applied. // reverse = If true, reverse the normals of the faces generated from the region. An untransformed region will have face normals pointing `UP`. Default: false -// vnf = If given, the faces are added to this VNF. Default: `EMPTY_VNF` // Example(3D): // region = [square([20,10],center=true), // right(5,square(4,center=true)), @@ -422,11 +433,10 @@ function _cleave_connected_region(region) = // color("gray")down(.125) // linear_extrude(height=.125)region(region); // vnf_wireframe(vnf,width=.25); -function vnf_from_region(region, transform, reverse=false, vnf=EMPTY_VNF) = +function vnf_from_region(region, transform, reverse=false) = let ( regions = region_parts(force_region(region)), vnfs = [ - if (vnf != EMPTY_VNF) vnf, for (rgn = regions) let( cleaved = path3d(_cleave_connected_region(rgn)), face = is_undef(transform)? cleaved : apply(transform,cleaved), @@ -684,11 +694,11 @@ module vnf_polyhedron(vnf, convexity=2, extent=true, cp=[0,0,0], anchor="origin" // Module: vnf_wireframe() // Usage: -// vnf_wireframe(vnf, ); +// vnf_wireframe(vnf, [width]); // Description: // Given a VNF, creates a wire frame ball-and-stick model of the polyhedron with a cylinder for // each edge and a sphere at each vertex. The width parameter specifies the width of the sticks -// that form the wire frame. +// that form the wire frame and the diameter of the balls. // Arguments: // vnf = A vnf structure // width = width of the cylinders forming the wire frame. Default: 1 @@ -930,6 +940,7 @@ function _triangulate_planar_convex_polygons(polys) = // Arguments: // vnf = The original VNF to bend. // r = If given, the radius where the size of the original shape is the same as in the original. +// --- // d = If given, the diameter where the size of the original shape is the same as in the original. // axis = The axis to wrap around. "X", "Y", or "Z". Default: "Z" // Example(3D):