You can change the 3D model used for tracking before deployment and dynamically during runtime. You can change and manage 3D model references in the .vl config file.
In Unity, the easiest way is to place your model inside the Streaming Assets folder in your project’s Assets directory and reference it in the .vl config file. You need to use VisionLib’s prefabs or scripts to control the reference model usage. You can also use 3D meshes and GameObjects from the hierarchy as tracking references (experimental).
Have a look in the documentation. There are several articles with examples and explanations: