Both these parcels are open source. Users can use these parcels as the basis of 3D applications like motion simulation, finite element analysis, CAD, scientific visualization, etc. 'stCAD' allows users to create and manipulate assemblies, which are collections of 3D parts. The parts are 3D solids, which can be connected by joints, constraints, contacts, actuators, springs, dampers or forces. The parts and connections define the structure or mechanism that the assembly is meant to represent. Animation is possible, if the user can provide time series of position and orientation data for the parts.
Users can also obtain output data in the form of plots and tables.
The parcel 'stMbD' has been included to provide a functional demonstration, but its source code is hidden. Available solids are extrusions of rectangles, circles, ellipses and polygons. The solids can be positioned and oriented exactly in space, as are markers on the solids. Exact specification of linear and angular velocities of solids in space are also possible. Mass and inertia properties can be user specified or automatically computed based on uniform density.