Lets3dPrint scripts

A project's timeline written as plain lines you can read, change and run. Every step of the timeline is one line (a sketch is a short block). Change a number and press Run: the part rebuilds. Or write a script from scratch, with variables and loops.

# A plate with a row of pegs
w = 80          # Width (40 to 200)
d = 50          # Depth (20 to 120)
pegs = 5        # Pegs (1 to 12)

base = sketch on xy
  rect (-w/2, -d/2) to (w/2, d/2)
end
plate = extrude base by 5 as "Plate"

repeat i from 1 to pegs
  cylinder r 3 h 10 on xy offset 5 at (-w/2 + i * w / (pegs + 1), 0) join into plate
end
fillet plate edges 1, 3 r 2

Values and script files

The numbers set at the top of a script (outside sketches and loops) appear above it as Values: a field for each, and a slider when its comment ends with a range. The comment is its label. Change one and the part rebuilds.

cables = 6       # Cables (1 to 12)
cable = 5        # Cable diameter (2 to 12)
gap = 4          # Wall between cables

The comment lines at the very top describe the script. Save Script… in the script panel writes it as a .l3dscript file (plain text). File → Run Script File… (⇧⌘R, also in Create and ⌘K) opens one in any project: set its values, then add its steps to the end of the timeline, or let it replace the project. A script added to a project can use the project's steps and bodies by the names the script view gives them (plate, "Base plate").

Basics

• One command per line. # starts a comment.
• Numbers are millimetres and degrees. Write sums freely: w/2 + 3, sqrt(2) * 10.
• Functions: sin cos tan (degrees), sqrt abs min max round floor ceil, and pi.
• name = 12 sets a variable; name = <command> gives a step a name to refer to later.
• Points are (x, y); 3D points and vectors are (x, y, z).
• repeat i from 1 to 10 [step 2] … end repeats lines; if a > b … else … end chooses.
• Comparisons < <= > >= == !=, combined with and, or, not. true is 1, false is 0.
• Texts in quotes: label = "BOX"; texts compare with == and !=. A value like lid = "snap" # Lid (none, snap, screw) shows as a menu, rounded = true as a switch.
• define peg(x, y) … end names some lines; peg(10, 5) runs them with x and y set.

Any step can end with named "Its name" (its name in the timeline), as "Body name" (the body it creates) and suppressed.

Planes, faces, edges, operations

• Planes: xy, xz, yz, optionally offset 5; or a flat face of a body: face 3 of plate.
• Bodies: a step's name (plate) or a body's name in quotes ("Bracket").
• How a new solid combines: new, join, cut, intersect, optionally into plate.
• Faces and edges are numbered as the inspector shows them (from 1).
• Or name them by where they are, so the script works for any values: face top of box (also bottom, front, back, left, right; face side of rod is the biggest round face), shell box open top wall 2, fillet box edges vertical r 2 (also top, bottom, all).

Sketches

s = sketch on xy            # or: on face 6 of plate offset 2
  line (0, 0) to (40, 0) as base_line
  rect (0, 0) to (20, 10)
  circle (10, 5) r 3        # or d 6
  arc (0, 0) from (5, 0) to (0, 5)      # centre, start, end; add cw for clockwise
  curve (0, 0) (5, 10) (15, 10) (20, 0) # Bézier with two control points
  spline (0, 0) (10, 5) (20, 0)
  ellipse (0, 0) major (10, 0) minor 4
  polygon (0, 0) through (10, 0) sides 6   # add circumscribed
  slot (0, 0) to (20, 0) r 4
  text "Hello" at (0, 0) height 10 font "Helvetica-Bold" angle 0
  point (5, 5)
end

Add construction to a curve to keep it out of profiles. Name a curve with as to use it later: line s.base_line as an axis, or as a path.

Steps

Function to body

A formula made into a body: z "…" for a graph z = f(x, y) (also r, the distance from the centre), parametric "x", "y", "z" for a surface of u and v, or implicit "F" for F(x, y, z) = 0, inside where F < 0. Formulas are in quotes and use radians, + - * / ^, pi, e, sin cos tan asin acos atan atan2 sinh cosh tanh sqrt abs exp ln log10 min max floor ceil round sign pow hypot clamp, and the fractals mandelbrot(x, y, n), mandelbulb(x, y, z, n, iterations) and julia(x, y, z, a, b, c, d, iterations).

• Ranges: x -10 to 10 y -10 to 10 (graphs), u … v … (parametric), x … y … z … (implicit).
• Values the formulas use: with k 6 from 1 to 20, R 2 (the range is the slider's).
• log plots log(1 + z) for steep functions; width and height in mm; grid points (or cells).
• The body: base 2, thickness 1.2 below (or above, both), surface or inside; then on xz or on face 6 of plate, at (10, 0), and how it combines (join into plate). On a face, clip cuts a graph to the face's outline.

Map to body

A map file kept in the project (import it first with Generate → Import Map), or generated noise, made into a relief.

• Values: grey (white high), grey inverted, data (heights in the file), or colours from (x, y) to (x, y) values -500 to 4800 (the legend's two ends in pixels) or colours "Turbo" values 0 to 1, with stepped and tolerance 12.
• Contour lines: map "hills.svg" contours interval 10, terraces for flat steps, level 3 25 for one contour's height.
• Generated: map noise clouds|ridged|billow|cells|craters seed 4 size 20, with octaves, rough, lacunarity, warp, offset (x, y), tileable, falloff, terraces, cracks, jitter, count 40 radius 1 to 15. Add noise to a file: noise clouds seed 5 size 2 amount 0.02.
• Adjust: crop (0.1, 0.2) to (0.9, 0.8), nodata -9999, floor 0, top 3000, smooth 1, invert.
• Size: width 200 or scale 20000000 (1 : N), depth (generated), nolongitude, height 10 or exaggerate 20, grid 0.25 (mm).
• Body: base 2, thickness 1.6 below, surface, globe r 50 wall 2; outline shape circle, shape data, shape profile s at (0, 0) or, on a body's face (on face 6 of plate join into plate), shape face.