jamesporter · July 16, 2018 22:09 · Jul 16, 2018
diff --git a/openjscad-cheat-sheet.md b/openjscad-cheat-sheet.md
@@ -0,0 +1,154 @@
+# OpenJSCAD Cheat Sheet
+
+James Porter
+
+## 0. 3D
+
+* Architecture-style
+* x,y,z
+
+## 1. main
+
+Always have a main function which returns an object
+
+```js
+function main () {
+  return union(
+    difference(
+      cube({size: 3, center: true}),
+      sphere({r: 2, center: true})
+    ),
+    intersection(
+      sphere({r: 1.3, center: true}),
+      cube({size: 2.1, center: true})
+    )
+  ).translate([0, 0, 1.5]).scale(10);
+}
+
+```
+
+## 2. Basic Shapes: Cube
+
+```js
+cube({size: 1, center: true})
+cube({size: [1,2,3]})
+```
+
+* size `s` or `[x,y,z]`
+* center (location) `false` by default (at 'bottom' corner)
+
+## 3. Basic Shapes: Cylinder
+
+```js
+cylinder({r: 1, h: 10})
+```
+* r for radius
+* h for height
+* again can `center` or not (default)
+* `fn` to control detail
+
+## 4. Transforms: Scale
+
+```js
+scale(2,obj)
+scale([1,2,3],obj)
+```
+
+* can scale in simple way 
+* or per x,y,z
+
+
+## 5. Transforms: Translate
+
+```js
+translate([5,4,3], obj)
+```
+
+* Move by `[x,y,z]`
+* e.g. move up 5 units:
+
+```js
+translate([0,0,5], obj)
+```
+
+## 6. Transforms: Rotation
+```js
+rotate([90,0,45], obj)
+```
+
+* Rotate about `[x,y,z]` (respectively)
+* e.g. rotate about vertical by 90 degrees:
+
+```js
+rotate([0,0,90], obj)
+```
+
+**NB Degrees not radians**
+
+## 7. Operations: Union
+
+* Glue stuff together
+
+```js
+union([obj, another])
+union(obj, another)
+```
+
+## 8. Basic Shapes: Sphere
+
+```js
+sphere({r: 4})
+```
+* r for radius
+* `center` is true by default (unlike other primitive objects)
+* `fn` to control detail
+
+## 9. Basic Shapes: Polygon + linear_extrude
+
+List of points to make a (2D) polygon on x,y plane
+
+```js
+let p1 = polygon([ [0,0],[3,0],[3,3] ])
+let p2 = polygon({ points: [ [0,0],[3,0],[3,3] ] })
+```
+
+Then extrude with `linear_extrude`:
+
+```js
+linear_extrude({ height: 10 }, p1);
+linear_extrude({ height: 1 }, p2);
+```
+
+## 10. Operations: Intersect
+
+* Bit in all the shapes
+
+```js
+intersection(
+      sphere({r: 1.3, center: true}),
+      cube({size: 2.1, center: true})
+    )
+```
+
+* Can take bunch of arguments or array
+
+## 11. Operations: Difference
+
+* First shape with rest carved out
+
+```js
+ difference(
+      cube({size: 3, center: true}),
+      sphere({r: 2, center: true})
+    )
+```
+
+* Can take bunch of arguments or array
+
+## Appendix
+
+See [the full docs](https://openjscad.org/dokuwiki/doku.php?id=start)
+
+Adds some mathematical things like `sin` that work with degrees not radians.
+
+You might want to use `Math.{round,sin,cos,tan,floor,ceil,sqrt,random}` to generate things in simple way.
No results found