Autodesk Inventor
Autodesk Inventor is 3D-CAD modeling package produced by U.S.-based software company Autodesk. It is similar in functionality to SolidWorks. It is marketed as a relatively low-cost alternative to more expensive programs. As of 2003, it can run on ordinary personal computers, but it requires powerful processors and video cards to run.
Unlike AutoCAD, Inventor is based on newer, more advanced parametric modeling techniques. Users begin by designing parts. These parts can then be combined into assemblies. Editing parts and assemblies are two completely different things. As a parametric modeller, it should not be confused with traditional CAD programs. It is used in design and engineering to produce and perfect new products. Whereas in CAD programs the dimensions are geometry-driven, in a parametric modeller the geometry is dimension-driven. If the dimensions are altered, the gemoetry automatically updates based on the new dimension. Inventor also has a sheetmetal calculator, limited stress analysis tools, and, in v10, a 3D VIS based rendering and animation engine.
Parts in Inventor are made by defining features, which are based on sketches. For example, in order to make a simple cube, a user would first make a square sketch, then use the extrude tool to make a cube feature out of it. If a user then wanted to add a shaft coming out of the cube, he could add a sketch on the desired face, draw a circle, and then extrude that circle to create a shaft. The best aspect of this design is that all of the sketches and features can be edited later, without having to redo the entire part. This system of modeling is much more intuitive than cumbersome systems in older modeling environments, where one who wanted to change basic dimensions would usually have to delete the entire file and start over.
Parts are then connected to make assemblies. Assemblies can consist of both parts, and other assemblies. Parts are joined together by adding constraints between surfaces, edges, planes, point and axes. For example, if one was adding a sprocket onto a shaft, an insert constraint could be added to the shaft and the sprocket saying that the center of the shaft was the same as the center of the sprocket. The distance between the surface of the sprocket and the end of the shaft can also be specified with the insert contraint. Other constraints include flush, mate, insert, angle, and tangent.
This method of modeling allows for the creation of very large, complicated assemblies.