# footprints3

A 3D verion of [footprint2](https://openhome.cc/eGossip/OpenSCAD/lib3x-footprints2.html). 

**Since:** 2.4

## Parameters

- `cmds` : A list of `["forward", length]`s, `["turn", angle]`s, `["roll", angle]`s and `["pitch", angle]`s. 
- `start` : Set the start point of the turtle. Default to `[0, 0, 0]`.

## Examples
	    
	use <hull_polyline3d.scad>;
	use <turtle/footprints3.scad>;
	
	function xy_arc_cmds(radius, angle, steps) = 
		let(
			fa = angle / steps,
			ta = fa / 2,
			leng = sin(ta) * radius * 2
		)
		concat(
			[["turn", ta]],
			[
				for(i = [0:steps - 2])
				each [["forward", leng], ["turn", fa]]
			],
			[["forward", leng], ["turn", ta]]
		);

	poly = footprints3(
		concat(
			[
				["forward", 10],
				["turn", 90],
				["forward", 10] 
			], 
			xy_arc_cmds(5, 180, 12),
			[
				["pitch", 90],
				["forward", 10],
				["roll", 90]
			],
			xy_arc_cmds(5, 180, 12),
			[
				["forward", 10]
			]
		)
	);

	hull_polyline3d(poly, thickness = 1);

![footprints3](images/lib3x-footprints3-1.JPG)