Modifying Models for the End User

AGI currently supports two model formats, MDL and Collada. MDL is our native format and has been supported since the beginning. Collada, with a file extension of DAE, has been supported for about ten years. This blog relates only to our native format, MDL.

I am an end user. I don’t write code, I don’t build models and I’m not an engineer. Mostly I create content that supports other end users. Sometimes I need to make or modify a model used in STK. We have folks who build models full time but I try not to use any of their time if it is something I can do myself.

For analysis purposes, STK models objects as point masses. Shortly after STK was developed, AGI saw a need for users to visualize these objects as 3D models and not just a bunch of colored dots. We also wanted to give users the ability to create and modify their own 3D models without the additional burden of learning a whole new skill set. To this day, the only tools a user needs to work on MDL models is a text editor and our proprietary model viewer, MDE.

While our models are protected by copyright, we have never sold any of our models. They are all free. Aside from the copyright notice, they are unlicensed and shipped with no copy protection. Yet all of our models have a built in security feature that makes piracy virtually impossible. Nobody else uses them. While we have software that will convert Lightwave models to MDL, no software has ever been written that converts MDL to any another format.

Our models are plain text files with an MDL extension which means they're easy to manipulate and edit to add features or improve/change the look of them. By editing a .MDL file you can:

  • move, add or delete parts
  • change a color or texture
  • create or modify an articulation
  • attach a sensor to a part on a model
  • add vapor attach points

Below are a series of MDL knowledge articles that provide a working understanding of the topics above. You will also see links that describe specialized analysis and video production models.

There is also a knowledge article on How to Make and Use Custom Markers in STK. While this has nothing to do with models, it's useful to know when working with objects in the 2D and 3D windows.


Systems Tool Kit (STK)

Modeling and simulation software for digital mission engineering and systems analysis.