Model Recognition

This is a Work in Progress Article based on materials available on the Vuforia Library.

Model Targets

Introduction to Model Targets in Unity (Source: Vuforia Library)

Model Targets utilise 3D model data of an object (for example a 3D Scan or Digital Model).

Model Targets enable applications to track physical objects by using this digital data as reference information. Model targets can include rigid and opaque objects of different scales, from Architectual Landmarks to Small Figurines.

Requirements: Model Data

In order to create a Model Target, 3D model data must first be created. 3D CAD models and 3D Scans are suitable data sources.

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The Model Target itself must be a rigid object which does not contain transparent or shiny surfaces. The object must also remain in a fixed location.

See: Model Targets Supported Objects & CAD Model Best Practices (Vuforia Library)

Creating Model Targets

Model Targets are created using the Model Target Generator. This software converts a 3D model in to a Vuforia Engine dataset. This software is only available on Windows.

Figure 1.0 - Vuforia Model Target Generator

The Model Target Generator software will grade quality or suitability of the mesh, and allow a user to add "Guide Views" . This Guide View is an outline of a 3D model from a particular perspective.

From the Model Target Generator, you can export your Model Target dataset as a .unitypackage.

Import the .unitypackage in to your Unity Project.

Using Model Targets in Unity

Model Targets can be added in to a Unity Scene as GameObjects.

GameObject > Vuforia Engine > Model Targets > Model Target

Add an ARCamera to the Environment and enter an appropriate license key. Read more here.

Select the ModelTarget from the Hierarchy Window, and designate it a child of the ARCamera.

Ensure that the Model Target Behaviour scripts are correct: Inspector Window > Model Target Behaviour (Script)

• The Database and Model Target fields should match that of the recently imported database

• The Physical Length, Physical Width and Physical Height fields should match the physical dimensions of the real-world object that the project references.

• The Guide View Mode field should be set to Guide View 2D

Debug the application, and verify that when the Guide View aligns with the physical object, the guide view lines disappear.

When this occurs, the application is tracking the physical object.

Adding Content to the ModelTarget

Content, such as a rendered 3d model or annotations can be rendered upon the application tracking the object.

Add any asset or GameObject to the hierarchy window and designate it a child of the ModelTarget.

Other Resources

Model Targets (Vuforia Library)

Model Targets - Vuforia Engine Librarylibrary.vuforia.com

Vuforia Model Target Generator (Vuforia Developer Portal)

Engine Developer Portaldeveloper.vuforia.com

An Introduction to Model Targets in Unity (Vuforia Developer Library)

Unity - Vuforia Engine Librarylibrary.vuforia.com