added polyline3d

README.md

@@ -16,6 +16,7 @@ I've been using OpenSCAD for years and created some funny things. Some of them i
 
 - 3D
 	- [line3d](https://openhome.cc/eGossip/OpenSCAD/lib-line3d.html)
+	- [polyline3d](https://openhome.cc/eGossip/OpenSCAD/lib-polyline3d.html)
 
 - Transformations
 	- [hollow_out](https://openhome.cc/eGossip/OpenSCAD/lib-hollow_out.html)

docs/lib-polyline3d.md

@@ -0,0 +1,65 @@
+# polyline3d
+
+Creates a polyline from a list of `[x, y, z]` coordinates. It depends on the `line3d` module so you have to `include` line3d.scad.
+
+## Parameters
+
+- `points` : The list of `[x, y, z]` points of the polyline. : A vector of 3 element vectors. The points are indexed from 0 to n-1.
+- `thickness` : The line thickness.
+- `startingStyle` : The end-cap style of the starting point. The value must be `CAP_BUTT`, `CAP_CIRCLE` or `CAP_SPHERE` (defined in line3d.scad). The default value is `CAP_CIRCLE`. 
+- endingStyle : The end-cap style of the ending point. The value must be `CAP_BUTT`, `CAP_CIRCLE` or `CAP_SPHERE` (defined in line3d.scad). The default value is `CAP_CIRCLE`.
+- `fn` : It controlls the `$fn` value used by the `circle` and `sphere` module. The default value is `24`.
+
+## Examples
+
+	polyline3d(
+	    points = [
+	        [1, 2, 1], 
+	        [-5, -4, 2], 
+	        [-5, 3, 3], 
+	        [5, 5, 4]
+	    ], 
+	    thickness = 1
+	);
+
+![polyline3d](images/lib-polyline3d-1.JPG)
+
+	polyline3d(
+	    points = [
+	        [1, 2, 1], 
+	        [-5, -4, 2], 
+	        [-5, 3, 3], 
+	        [5, 5, 4]
+	    ], 
+	    thickness = 1,
+	    endingStyle = CAP_SPHERE
+	);
+
+![polyline3d](images/lib-polyline3d-2.JPG)
+
+	polyline3d(
+	    points = [
+	        [1, 2, 1], 
+	        [-5, -4, 2], 
+	        [-5, 3, 3], 
+	        [5, 5, 4]
+	    ], 
+	    thickness = 1,
+	    startingStyle = CAP_SPHERE,
+	    endingStyle = CAP_SPHERE
+	);
+
+![polyline3d](images/lib-polyline3d-3.JPG)
+
+	r = 20;
+	h = 5;
+	fa = 15;
+	circles = 10;
+	
+	points = [
+	    for(a = [0:fa:360 * circles]) 
+	        [r * cos(a), r * sin(a), h / (360 / fa) * (a / fa)]
+	];
+	polyline3d(points, thickness = 1);
+
+![polyline3d](images/lib-polyline3d-4.JPG)

src/polyline3d.scad

@@ -0,0 +1,35 @@
+/**
+* polyline3d.scad
+*
+* Creates a 3D polyline from a list of `[x, y, z]` coordinates. 
+* It depends on the line3d module so you have to include line3d.scad.
+* 
+* @copyright Justin Lin, 2017
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib-polyline3d.html
+*
+**/
+
+module polyline3d(points, thickness, startingStyle = CAP_CIRCLE, endingStyle = CAP_CIRCLE, fn = 24) {
+    module line_segment(index) {
+        styles = index == 1 ? [startingStyle, CAP_BUTT] : (
+            index == len(points) - 1 ? [CAP_SPHERE, endingStyle] : [
+                CAP_SPHERE, CAP_BUTT
+            ]
+        );
+        
+        line3d(points[index - 1], points[index], thickness, 
+               p1Style = styles[0], p2Style = styles[1], 
+               fn = fn);
+    }
+
+    module polyline3d_inner(points, index) {
+        if(index < len(points)) {
+            line_segment(index);
+            polyline3d_inner(points, index + 1);
+        }
+    }
+
+    polyline3d_inner(points, 1);
+}