Groups

To view a list of groups, go to the home page of the text window. This is accessible from the link at the top left of the text window, or by pressing Esc. To view a group’s page, click its name in the list.

All groups have a name. When the group is created, a default name (e.g., ‘g008-extrude’) is assigned. The user may change this name; to do so, go to the group’s page in the text window, and choose [rename].

Groups that create a solid (e.g. extrudes or lathes) have a solid model as option, which is displayed in the page in the text window. The group can be merged as union, which adds material to the model, or as difference, which cuts material away.

The union and difference operations may be performed either as triangle meshes, or as exact NURBS surfaces. Triangle meshes are fast to compute and robust, but they require any smooth curves to be approximated as piecewise linear segments. The NURBS surface operations are not as robust, and will fail for some types of geometry; but they represent smooth curves exactly, which makes it possible for example to export a DXF in which a circular arc appears as an exact circle, instead of many piecewise linear edges.

These groups also have a color, which determines the color of the surfaces they produce. To change the color, click one of the swatches in the group’s page in the text window.

The group’s page in the text window also includes a list of all requests, and of all constraints. To identify a constraint or a request, hover the mouse over its name; it will appear highlighted in the graphics window. To select it, click the link in the text window. This is equivalent to hovering over and clicking the actual object in the graphics window.