What is commercial software and what are some examples?

You're right—using SendKeys isn't the most reliable approach. Instead, you can use AutoCAD's ActiveX API to open a drawing properly in VBA.

Yes, you can access material, designation, and user-defined iProperties through the Inventor API using Document.PropertySets. For example, oDoc.PropertySets('Design Tracking Properties')('Material') gets the material, and custom properties are under 'User Defined Properties'.

In Autodesk Inventor, parameters default to 3 decimal places for display, but you can get full precision by accessing the .Value property directly in VBA/VB.NET, which returns a Double with full internal precision (~15-16 digits). Avoid using .Expression or .FormattedValue if you need raw numeric accuracy.

You can buy CAD software directly from the official websites of the software developers, through authorized resellers, or from major software retailers. For free software, downloads are available from the official project websites.

To learn computer-aided design (CAD) software, you should first choose a program based on your goals, then follow a structured path of learning fundamentals, practicing with projects, and utilizing the many online resources available.