CAD-Zilla uses the Modelzilla framework by defining some ShapeNode subclasses that each build a different kind of geometrical shape. The shapes are divided into several categories. The polygon primitives build line and curve type geometries that are represented by discretely sampled polygons, based on an input that does not require other shapes. Examples are circles, poly-lines, and arcs. The polygon constructions build line and curve type geometries that use other polygons as input. Examples are smoothed polygons, joined polygons, and rounded polygons. The region constructions build 2D solids, based on polygon boundaries, and regions formed from solid Boolean operations of other regions. The solid primitives build 3D solids that do not require other shapes as input. Examples are spheres and wedges. The solid constructions build solids based on other solids. Examples are solid Boolean operations of other solids. Each shape adds a number of input nodes to itself in its constructor. These include PointNodes for holding coordinates, ScalarNodes, and NodeSetNodes for referencing input geometries.

Shapes are constructed by a classic Constructive Solid Geometry system. The user starts his model with primitive shapes defined by small repository nodes like coordinates and scalar values. He then combines these shapes into more complicated shapes. In doing so, he creates a new repository node that holds the input shapes as children. The CAD-Zilla user interface gives options regarding how the input should be related to the construction shape. Instead of taking the input shapes as children, links can be made to the input shapes that are then left in their original place in the tree, or copies of the input can be made. These options allow the user to keep their previous objects where they want them.

The key construction was made by first building the outline of the flat profile of the key using polygon constructions. A circle was made for the hole. The outer polygon and the circle were extruded normal to the polygon plane to give the key a thickness. At this stage there are two objects at the root level. The circle extrusion was then subtracted from the outer polygon extrusion. Then, more solids were built using some ski-shaped bent sweeps and subtracted to form the long slots.

Construction Abilities

• Polygon primitives
• Line
• Polyline
• Rectangle
• Circle
• Ellipse
• Arc from center, radius, angle, angle
• Arc from start, circumference point, end
• Arc from start, tangent, end
• Inscribed regular polygon
• Circumscribed regular polygon
• Polygon constructions
• Spline polygon with a variety of smoothing functions
• Join (chain) polygons
• Break polygons
• Fillet polygons
• Chamfer polygons
• Trim polygons
• Extend polygons
• Offset polygons
• Polygon by user defined analytical function
• Convenient multi curve function
• Region constructions
• Convert polygon to region
• Union regions
• Intersect regions
• Subtract regions
• Solid primitives
• Box
• Wedge
• Sphere
• Cylinder
• Cone
• Torus
• Solid constructions
• Extrude region or polygon
• Revolve region or polygon
• Sweep region or polygon over a path
• Multiple section multiple path sweep ("Ruled Surface")
• Scale sweep
• Union Solids
• Intersect Solids
• Subtract Solids
• Cleave Solids
• Section Solids

• Point mark snap
• Line end point snap
• Line middle snap
• Intersection snap
• Arc, circle center snap
• Nearest to line snap
• Intersection of polygon and UCS plane snap
• User vertex snap