Shapes

Shapes are the starting point of every model. llmcad provides three solid primitives, all centered at the origin.

Box

Box(width: float, length: float, height: float,
    name: str = "", color: str | tuple = None) -> Body

Creates a rectangular box centered at the origin.

Parameter	Description
width	Extent along X axis
length	Extent along Y axis
height	Extent along Z axis
name	Optional name for the body
color	Optional color (name or RGB tuple)

Named faces: top, bottom, front, back, left, right

from llmcad import Box

plate = Box(100, 60, 10, name="plate")

print(plate.top)     # FaceRef('top', center=(0.0, 0.0, 5.0))
print(plate.front)   # FaceRef('front', center=(0.0, -30.0, 0.0))
print(plate.right)   # FaceRef('right', center=(50.0, 0.0, 0.0))

Face layout

        top (+Z)
        ┌──────────┐
       /          /|
      /  back    / |
     /  (+Y)   /  | right (+X)
    ┌──────────┐   |
    |          |   |
    |  front   |  /
    |  (-Y)    | /
    └──────────┘
      bottom (-Z)

The local coordinate axes for each face:

Face	x_dir	y_dir	Normal
top	+X	+Y	+Z
bottom	+X	+Y	-Z
front	+X	+Z	-Y
back	-X	+Z	+Y
right	+Y	+Z	+X
left	-Y	+Z	-X

Cylinder

Cylinder(diameter: float, height: float,
         name: str = "", color: str | tuple = None) -> Body

Creates a cylinder centered at the origin, axis along Z.

Parameter	Description
diameter	Cylinder diameter (not radius)
height	Extent along Z axis
name	Optional name
color	Optional color

Diameter, not radius

Cylinder(10, 20) creates a cylinder with diameter 10 (radius 5) and height 20. This matches how engineers typically specify parts.

Named faces: top, bottom, wall

from llmcad import Cylinder

cyl = Cylinder(20, 50, name="pin")

print(cyl.top)   # FaceRef('top', center=(0.0, 0.0, 25.0))
print(cyl.wall)  # FaceRef('wall', center=(0.0, 0.0, 0.0))

Sphere

Sphere(diameter: float,
       name: str = "", color: str | tuple = None) -> Body

Creates a sphere centered at the origin.

Parameter	Description
diameter	Sphere diameter (not radius)
name	Optional name
color	Optional color

Named faces: surface

from llmcad import Sphere

ball = Sphere(30, name="ball")
print(ball.faces["surface"])

Colors

All shapes accept an optional color parameter:

plate = Box(100, 60, 10, color="steel")
pin = Cylinder(8, 20, color=(0.8, 0.2, 0.2))  # RGB tuple, 0-1

You can also set color after creation:

plate.color = "red"

Available named colors: red, green, blue, yellow, orange, white, black, gray/grey, steel, silver, cyan, magenta, purple, pink, brown.