rod

rod(size, h, d, r, orientation=z, anchor=$inward)

rod is intended as a replacement for the cylinder module.

parameters h, d, and r are equivalent to their counterparts within the cylinder module. Cylinder also offers an additional parameter, size that operates much like the size parameter of the box module - size.x and size.y define diameters along the x and y axes, and size.z defines the height. This is done in order to standardize parameters across the relativity.scad primitives.

Parameters d1, d2, r1, and r2 are not supported by the rod module as they do not interact well with the align module. Future versions may change this, however.

Alignment

rod offers all the existing functionality of cylinder, but unlike cylinder, rod renders any child module passed to it:

rod(d=10,h=10)
sphere(d=15);

By default, child modules will render with their origins at the center of their parent module. This can be changed using standard built-in modules like transform. rod exposes a special variable, $parent_size, that allows translation relative to the size of the parent. $parent_size.x and $parent_size.y expose the x and y diameters and $parent_size.z exposes the height.

rod(d=10,h=10)
translate([0,0,$parent_size.x/2])
sphere(d=15);

relativity.scad also offers a wrapper for the translate module, called align. Statements such as the one above can be streamlined using the align module:

rod(d=10,h=10)
align([0,0,1])
sphere(d=15);

Centering

rod also streamlines its own translation. Consider a statement such as this:

cylinder_height = 10;
translate([0,0,cylinder_height/2])
cylinder(d=10, h=cylinder_height, center=true);

rod offers a parameter, anchor, that defines where you want the origin to be relative to rod. The statement above is equivalent to the following:

rod(d=10,h=10, anchor=[0,0,-1]);

anchor acts as a complete replacement for the center parameter exposed by cylinder. The following statements are equivalent:

rod(d=10,h=10, anchor=[0,0,0]);
cylinder(d=10,h=10, center=true);

rod(d=10,h=10, anchor=[0,0,-1]);
cylinder(d=10,h=10, center=false);