20 December 2006

CAD File Formats

One of the biggest headaches in CAD/CAM is file formats. In fact it is a complete nightmare.

Every product out there tends to have its own proprietary format and they normally contain deliberate gotchas and obfuscation to try and prevent reverse engineering the formats. Also if they provide a DLL to read the format they will deliberate hobble it as well as making sure you have signed some sort of EULA agreement. That is if you can get to an agreement as if they know you have signed up with another competitor to read their format they might not be so forthcoming with their own.

All in all it is the dinosaur's way of doing things, especially in the day and age of open formats for things like Office Suites.

There are open formats, and most CAD packages allow you to export your data in one of these defined formats. But they rarely follow the formats correctly and throw away lots of information that would otherwise be useful, so you really want to use the original data. The most annoying part is having to extrapolate the intentional and unintentional errors that deviate from the specification.

Normally you will have to either reverse engineer the format yourself, manage to get a deal with the vendor of the product you want to be compatible with, or find someone who supplies the reverse engineering service as a library you can integrate.

It would be so nice if there was a format that could be used for interoperability, but I think most companies like tying people down to their programs and it would require a sea change like what happened with OpenOffice and the Open Document Format (ODF).