README.md

geoscad

Geometry Tools for SolidPython wrapping for OpenSCAD

OpenSCAD is a great tool for defining 3 dimensional shapes.

Solid Python is a great tool for creating OpenSCAD descriptions using Python.

The goal of geoscad is to provide a set of general purpose aids useful across many 3d projects.

The geoscad library uses numpy for speed.

Source is maintained at geoscad.

Examples of use can be found at print3d.

as units

Most 3d printer software expect dimensions to be millimeters, while for design purposes some other scale is more conceptually useful. The as_units module makes this translation to millimeters easy.

A collection of objects in as_units function as scaling tools when used as the right hand side of a multiplication. For example

from geoscad.as_units import inches
width = 3.5 * inches

will set width to a 88.9 which is the millimeter equivalent of 3.5 inches.

To determine the size in millimeters of an 8 foot railroad tie modeled in nscale at a ratio of 1:160 one can use nscale_feet

tie_length = 8 * nscale_feet

The division operation can be used to reverse the calculation:

width_in_inches = width / inches

Sometimes it is useful to have a measurement which exactly equals an even number of printing layers, An example would be a design that uses a repeating pattern. Making the pattern repeat on even layers means the printing will have less interaction with the pattern frequency. The layers2 object can be used to achieve this:

pattern_height = 12.345 @ even_layer

Note the use of the @ operation. When this is used instead of * then the measurement will snap to the nearest even layer. The same result can be achieved using @ with dimensional layers:

width = 3.5 @ inches

You can also make your own scaling objects:

ho_scale_inches = AsUnits(1 / 87.1 * inches, 'ho"')
tie_length = 8 * ho_scale_inches

The @ operator will invoke the snapping function of an AsUnits object. You can define your own snapping function to accomodate different needs, such as a printer with resolution that differs from the default assumption of 0.1 millimieters.

Units can be applied to either numbers or lists. For example [1, 2, 3] * inches will return [25.4, 50.8, 76.2]