From 84d2e3d417eaed49f65deeb7fa8b9f7580d9e5c2 Mon Sep 17 00:00:00 2001
From: Adrian Mariano <avm4@cornell.edu>
Date: Sun, 15 Jan 2023 09:25:38 -0500
Subject: [PATCH] Add linear_sweep examples with disconnected texture ends and
 show fix

---
 skin.scad | 65 +++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 49 insertions(+), 16 deletions(-)

diff --git a/skin.scad b/skin.scad
index 2310d7b..5e0d17d 100644
--- a/skin.scad
+++ b/skin.scad
@@ -625,28 +625,61 @@ function skin(profiles, slices, refine=1, method="direct", sampling, caps, close
 //        ]
 //   ];
 //   linear_sweep(path, texture=tex, tex_size=[5,5], h=40);
-// Example: VNF tile that has no top/bottom edges and produces a disconnected result
-//   shape = skin([
-//                 rect(2/5),
-//                 rect(2/3),
-//                 rect(2/5)
-//                ],
-//                z=[0,1/2,1],
-//                slices=0,
-//                caps=false);
-//   tile = move([0,1/2,2/3],yrot(90,shape));
-//   linear_sweep(
-//       circle(20), texture=tile,
-//       tex_size=[10,10],tex_scale=5,
-//       h=40,convexity=4);
-
-
 // Example: As Function
 //   path = glued_circles(r=15, spread=40, tangent=45);
 //   vnf = linear_sweep(
 //       path, h=40, texture="trunc_pyramids", tex_size=[5,5],
 //       tex_scale=1, style="convex");
 //   vnf_polyhedron(vnf, convexity=10);
+// Example: VNF tile that has no top/bottom edges and produces a disconnected result
+//   shape = skin([rect(2/5),
+//                 rect(2/3),
+//                 rect(2/5)],
+//                z=[0,1/2,1],
+//                slices=0,
+//                caps=false);
+//   tile = move([0,1/2,2/3],yrot(90,shape));
+//   linear_sweep(circle(20), texture=tile,
+//                tex_size=[10,10],tex_scale=5,
+//                h=40,convexity=4);
+// Example: The same tile from above, turned 90 degrees, creates problems at the ends, because the end cap is not a connected polygon.  When the ends are disconnected you may find that some parts of the end cap are missing and spurious polygons included.  
+//  shape = skin([rect(2/5),
+//                rect(2/3),
+//                rect(2/5)],
+//               z=[0,1/2,1],
+//               slices=0,
+//               caps=false);
+//  tile = move([1/2,1,2/3],xrot(90,shape));
+//  linear_sweep(circle(20), texture=tile,
+//               tex_size=[30,20],tex_scale=15,
+//               h=40,convexity=4);
+// Example: This example shoes some endcap polygons missing and a spurious triangle
+//   shape = skin([rect(2/5),
+//                 rect(2/3),
+//                 rect(2/5)],
+//                z=[0,1/2,1],
+//                slices=0,
+//                caps=false);
+//   tile = xscale(.5,move([1/2,1,2/3],xrot(90,shape)));
+//   doubletile = vnf_join([tile, right(.5,tile)]);
+//   linear_sweep(circle(20), texture=doubletile,
+//                tex_size=[45,45],tex_scale=15, h=40);
+// Example: You can fix ends for disconnected cases using {{top_half()}} and {{bottom_half()}}
+//   shape = skin([rect(2/5),
+//                 rect(2/3),
+//                 rect(2/5)],
+//                z=[0,1/2,1],
+//                slices=0,
+//                caps=false);
+//   tile = move([1/2,1,2/3],xrot(90,shape));
+//   vnf_polyhedron(
+//     top_half(
+//       bottom_half(
+//         linear_sweep(circle(20), texture=tile,
+//                     tex_size=[30,20],tex_scale=15,
+//                     h=40.2,caps=false),
+//       z=20),
+//     z=-20)); 
 
 module linear_sweep(
     region, height, center,