If the Vuforia Database is not trained Vuforia Engine requires that the user hold their device at a particular angle relative to the object, and at a particular distance to initialize tracking of a Model Target. To aid with this process, your app will typically draw an image showing an approximation of the object from this distance and viewing angle, so that the user just needs to move their device until the object matches the image. When they do this, tracking can begin.
In Vuforia Engine, both the image and the particular angle/distance relative to the object that image represents is called a Guide View.
For an indication of how Guide Views work within a typical Model Target application, see Introduction to Model Targets in Unity and the Model Target Test App User Guide.
Guide Views in Advanced Model Target Databases
Using Advanced Model Target Databases in your application, you are also able to detect and track one out of several different objects (one active at a time), or you may want to have multiple Guide Views for a single object (for example, if you have a very large object and you want to provide a different user experience depending on which side the user approaches the object from).
Therefore, the Model Target Generator allows you to define multiple Guide Views per Model Target, and/or merge multiple Model Target databases together through a cloud-based training process that outputs a single Advanced Model Target database.
For applications using this feature we recommend to display a search-frame or similar UX to indicate visually that the application is actively searching for one ore more objects and/or Guide Views.
For more information, see Model Target Guide View and Advanced Model Target Databases.
Guide View in Advanced Model Target 360 Databases
The Advanced Model Target 360 feature differs from the other Model Target databases as it can detect and track one object without displaying a Guide View that first needs to be aligned with the object from a wide variety of angles defined in the MTG. We still recommend to display a symbolic guidance UX, so the end-user get's an indication what is the object the application is prepared to pick-up.
The Advanced Model Target 360 database is trained in the cloud-based training process performed through the Model Target Generator.
See Getting Started with Advanced Model Target 360 and Model Target Guide View, for more information.