dotSCAD/docs/lib3x-t3d.md

t3d

An implementation of 3D Turtle Graphics with Fluent API. When using the function, imagine that you are sitting on a turtle. You move or turn the turtle from the your viewpoint, not the viewpoint of OpenSCAD coordinates.

For more details, please see 3D turtle graphics.

Since: 2.1

Parameters

• t : The data of a turtle. t3d() with no arguments will return a turtle with the point [0, 0, 0] and the unit vectors [[1, 0, 0], [0, 1, 0], [0, 0, 1]].
• cmd : It accepts a string or a list of commands.
  • Given a string: "xturn", "yturn", "zturn", "xforward", "yforward", "zforward", "point" or "unit_vectors". If "xturn", "yturn" or "zturn" is provided, the angle parameter is required. If "xforward", "yforward" or "zforward" is provided, leng is required. "point" and "unit_vectors" are used to get respective data from a turtle.
  • Given a list: [[cmd1, value], [cmd2, value2], ...]. For example, [["xforward", 10], ["zturn", 120]] will forward a turtle 10mm along the x axis and turn it 120 degrees around the z axis from your viewpoint.
  • "roll", "pitch", "turn" and "forward" are supported since 3.3.
• point : Set the position of a turtle.
• unit_vectors : Set the unit vectors of a turtle.
• angle : Set the angle of a turtle if cmd is not provided. Turn a turtle if cmd is "xturn", "yturn" or "zturn".
• leng : Forward a turtle if cmd is "xforward", "yforward" or "zforward".

Examples

use <turtle/t3d.scad>
use <polyline_join.scad>

leng = 10;
angle = 120;
thickness = 1;

t = t3d(point = [0, 0, 0]);
t2 = t3d(t, "forward", leng = leng);
t3 = t3d(t2, [
    ["turn", angle],
    ["forward", leng]
]);
t4 = t3d(t3, [
    ["turn", angle],
    ["forward", leng]
]);   

polyline_join(
    [for(turtle = [t, t2, t3, t4]) t3d(turtle, "point")]
) sphere(thickness / 2);

use <line3d.scad>
use <turtle/t3d.scad>

module tree(t, leng, leng_scale1, leng_scale2, leng_limit, 
			angleZ, angleX, width) {
	if(leng > leng_limit) {
		t2 = t3d(t, "forward", leng = leng);

		line3d(
			t3d(t, "point"), t3d(t2, "point"), 
			width);

		tree(
			t3d(t2, "turn", angle = angleZ),
			leng * leng_scale1, leng_scale1, leng_scale2, leng_limit, 
			angleZ, angleX, 
			width);

		tree(
			t3d(t2, "roll", angle = angleX), 
			leng * leng_scale2, leng_scale1, leng_scale2, leng_limit, 
			angleZ, angleX, 
			width);
	}    
}

leng = 100;
leng_limit = 1;
leng_scale1 = 0.4;
leng_scale2 = 0.9;
angleZ = 60;
angleX = 135;
width = 2;

t = t3d(point = [0, 0, 0]);

tree(t, leng, leng_scale1, leng_scale2, leng_limit, 
	angleZ, angleX, width);