Argument names are optional if given in the order shown here.Ĭube(size =, center = true/false) When center is true, the cube is centered on the origin. 4.3 Point repetitions in a polyhedron point listĬreates a cube in the first octant.Using the parameter angle (with OpenSCAD versions 2016.xx), a hook can be modeled. Rotate_extrude(convexity = 10, $fn = 100) The number of fragments used by the extrusion can also be increased. Increasing the number of fragments composing the 2D shape improves the quality of the mesh, but takes longer to render. Examples Ī simple torus can be constructed using a rotational extrude. $fa, $fs and $fn must be named parameters. $fn : fixed number of fragments in 360 degrees. $fs : minimum circumferential length of each fragment. $fa : minimum angle (in degrees) of each fragment. The direction of the sweep follows the Right Hand Rule, hence a negative angle sweeps clockwise. Specifies the number of degrees to sweep, starting at the positive X axis. You must use parameter names due to a backward compatibility issue.Ĭonvexity : If the extrusion fails for a non-trival 2D shape, try setting the convexity parameter (the default is not 10, but 10 is a 'good' value to try). Usage linear_extrude(height = 5, center = true, convexity = 10, twist = -fanrot, slices = 20, scale = 1.0, $fn = 16) This can be used to rotate the object at its center, as if it is a spiral pillar, or produce a helical extrusion around the Z axis, like a pig's tail.Ī scale parameter is also included so that the object can be expanded or contracted over the extent of the extrusion, allowing extrusions to be flared inward or outward. In OpenSCAD Extrusion is always performed on the projection (shadow) of the 2d object xy plane and along the Z axis so if you rotate or apply other transformations to the 2d object before extrusion, its shadow shape is what is extruded.Īlthough the extrusion is linear along the Z axis, a twist parameter is available that causes the object to be rotated around the Z axis as it is extruding upward. Linear Extrusion is an operation that takes a 2D object as input and generates a 3D object as a result. 4.2 Extrude parameters for linear extrusion only.4.1 Extrude parameters for all extrusion modes.It is recommended to perform extrusion on shapes that remains strictly on the X-Y plane. What actually happens is that any information in the third coordinate (the Z coordinate) is ignored for any 2D shape, this process amounts to an implicit projection() performed on any 2D shape before the extrusion is executed. While transformations that operates on both 2D shapes and 3D solids can move a shape off the X-Y plane, when the extrusion is performed the end result is not very intuitive. Rotate_extrude() emulates throwing a vesselīoth extrusion methods work on a (possibly disjointed) 2D shape which exists on the X-Y plane. Rotational extrusion is similar to the process of turning or 'throwing' a bowl on the Potter's wheel. Linear_extrude() works like a Playdoh extrusion press Linear extrusion is similar to pushing Playdoh through a press with a die of a specific shape.

OpenSCAD provides two commands to create 3D solids from a 2D shape: linear_extrude() and rotate_extrude(). The text in its current form is incomplete.Įxtrusion is the process of creating an object with a fixed cross-sectional profile.

Spiral in openscad