Add Mega Tracking Targets

This article describes how to add and configure Mega tracking targets.

Before You Start

Check Is My Localization Library Ready for Use?
Import the Latest Version of the EasyAR Plugin and Enable the Mega Feature
Understand the basic concepts and usage of Unity AR Tracking Targets

Note

The following content and tools are only applicable to the process of developing Unity applications using EasyAR Mega.

If you are developing a mini-program, please refer to Create and Upload Annotations Using the Unity Editor (Mini-program Development).

If you are not developing a Unity application but want to view the Mega mapping results, please refer to Preview the 3D Real-world Mesh in the Mega User Guide.

If you are not developing a Unity application but need to simulate the operation to view the localization effect, please refer to Preview the Simulation Operation Effect in the Mega User Guide.

The content of this article requires the following Unity packages to be imported into the project:

Version >= 4003
Version 4.7 - 4002

com.easyar.sense

Mega's tracking target is an empty object containing the MegaBlockController component, which represents a block in Unity.

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Note

When the com.easyar.mega package is not imported, the editor functions of the block are unavailable, but it does not affect the tracking effect and functions at runtime.

If the Mega feature is not correctly enabled in the configuration, it cannot be used.

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Create Tracking Targets

Version >= 4003
Version 4.7 - 4002

Right-click on the blank area in the Hierarchy view. You can create a Mega tracking target through the menu EasyAR Sense > Mega > Target : Mega Block.

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In the script, you can use ARSessionFactory.CreateController to create it.

ARSessionFactory.CreateController<MegaBlockController>();

Add tracking targets in the editor

Using this method requires configuring BlockHolder.BlockRootSource as External (default) or Mixed.

First, you need to add the Block Viewer for Unity Developer tool.

Right-click on the blank area in the Hierarchy view. You can add the Block Viewer tool for Unity development through the menu EasyAR Mega > Tool > Block Viewer for Unity Developer (Edit Mode).

Important

When developing Mega applications with Unity, you must use the Block Viewer for Unity Developer tool. Other tools under the EasyAR Mega > Tool menu are not suitable for Unity application development.

Although the Annotation Tool also has similar functions, some functions of this tool will be removed in future versions, so it is not recommended to use it.

The annotation function (only the annotation itself) of the Annotation Tool will soon be migrated to the EasyAR Development Center webpage. The block mesh loading and model placement are not affected.

After the tool is successfully added, a EasyAR.Mega.BlockViewer (Dev) node and a MegaBlocks node will be added to the scene hierarchy.

Then use the tool to generate tracking targets.

Select the EasyAR.Mega.BlockViewer (Dev) node, fill in the EasyAR account information in the Inspector panel and log in;

Click the button on the right side of Mega Cloud Service;

Select the Mega positioning service you need to use and click OK.

After selecting the service, the block list in the current library will be displayed under the MegaBlocks node and on the tool panel.

Tip

Why is there nothing under my MegaBlocks?

It is recommended to check Is my positioning library ready for use?

By now, the tracking target blocks have been generated. Each child node starting with Block_ under the MegaBlocks node represents a block tracking target.
Automatically add tracking targets when positioning is successful

Using this method requires configuring BlockHolder.BlockRootSource as Internal or Mixed.

In these two modes, if a new block is located and there is no such block under the BlockHolder.BlockRoot node, this new block will be automatically added under the BlockHolder.BlockRoot node. If the BlockHolder.BlockRoot does not exist, it will be automatically created.

Tip

When automatically adding tracking targets when positioning is successful, the block model cannot be loaded, and only the block tracking target can be added.
Add tracking targets in the script

Using this method requires configuring BlockHolder.BlockRootSource as Internal or Mixed. In this case, if the BlockHolder.BlockRoot does not exist, it will be automatically created. Or, when BlockHolder.BlockRootSource is External, you can specify the BlockHolder.BlockRoot object in the editor in advance.

Note

If a block is not in the positioning library, even if it is added to the scene using a script, the block cannot be located.

You can use the BlockHolder.Hold method to add a new block under the BlockHolder.BlockRoot node. This method is usually used when using an ema annotation file. After the script reads the annotation information, it adds the block.

For example, the following code snippet shows how to use the information in the annotation file to add a block:
```
foreach (var item in ema.blocks)
{
    var info = new BlockController.BlockInfo { ID = item.id.ToString(), Timestamp = item.timestamp };
    if (!item.keepTransform && item.location.OnSome)
    {
        blockHolder.Hold(info, item.location.Value);
    }
    else
    {
        blockHolder.Hold(info, item.transform.ToUnity());
    }
}
```
Tip

When using a script to add tracking targets at runtime, the block model cannot be loaded, and only the block tracking target can be added.

Configure Tracking Targets

Configure the target data source

Version >= 4003
Version 4.7 - 4002

Tracking targets can only be recognized and tracked after their sources are correctly configured.

In the Hierarchy view, you can select the block node and fill in the block's ID and Name.

In the script, you can modify Source before the component MonoBehaviour.Start() to set the block's source.

block.Source = new MegaBlockController.BlockInfoSourceData(id, name);

Among them:

The block id is the unique identifier of the block and must be filled in.
The block name is the name of the block and can be filled in at will as needed. It is generally recommended to fill in the real name of the block for easy identification.

Tip

The block id and name can be obtained from the corresponding positioning library in the EasyAR Development Center.

If there is no block data in the positioning library, you need to add the required Block to the positioning library and check again that the cloud positioning library is valid.

Specify the target to be used, i.e., the block, in MegaTrackerFrameFilter.

In most cases, it is recommended to keep the default configuration, that is, import the block using Mega Studio in the editor.

Select the Mega Tracker object under the session, and the Block Root Source option should remain External (default).

At the same time, you need to specify Block Root as the MegaBlocks object in the scene.

Modifying the Block Root Source option can specify other block source methods. For example, when importing data using ema, the Internal or Mixed options are usually selected.

In the script, you can modify BlockHolder.BlockRootSource to achieve the same effect.

Configure the Tracker Used by the Target

Version >= 4003
Version 4.7 - 4002

The tracking target will be loaded by the configured tracker and tracked after being correctly located.

In the Hierarchy view, you can select the block node and then select Mega Tracker in the session.

In the script, you can modify Tracker to set the tracker for the block.

block.Tracker = megaTracker;

Tracker can be modified at any time during runtime. Loading/unloading will occur while the session is running. If you set Tracker to null, the target will be unloaded from the previously set tracker. Block loading is a virtual process and will not fail.

Note

There are several key conditions for a target to be tracked:

The id of MegaBlockController.Source must be correctly configured before MonoBehaviour.Start().
The block corresponding to the id of Source must exist in the positioning library.
MegaBlockController.Tracker must be configured to use the correct positioning library.

Normally, no additional configuration is required. However, if you need multi-target tracking control, you can make corresponding settings.

In most Mega usage scenarios, there is no need to use multiple targets. Before you master how to avoid the mutual influence of multiple blocks, it is recommended to put only one block in a positioning library.

Tip

In principle, Mega calculates the device's position in all blocks, rather than selecting the blocks the device sees from the positioning library. Improper use may lead to performance degradation due to data confusion and other reasons.

Select the Mega Tracker object under the session. Modifying the Multi Block option can enable or disable the multi-target tracking function.

In the script, you can modify BlockHolder.MultiBlock to achieve the same effect.

Warning

Generally, there can only be one block in a positioning library at the same time.

Modifying the multi-target configuration will affect the tracking effect. It is generally not recommended to modify it. Please use it under the guidance of EasyAR technical support.

If this configuration has been modified during the application execution, please be sure to mention this when reporting issues to EasyAR.

Tracking the Lifecycle of a Target

Version >= 4003
Version 4.7 - 4002

A common lifecycle for tracking a target is as follows:

flowchart LR
  sstart((session start))
  sstop([session stop])
  
  start("Target.Start")
  load("Load")
  tracking[["Continuous Tracking"]]

  sstart --> load --> tracking --> sstop
  start -. "Target.Tracker = tracker" .-> load

The process can be roughly divided into several stages:

Loading: The tracking target is loaded by the configured tracker. This occurs after the target's own Start() and the session starts.
Tracking process: After the tracking target is located, the tracker will continuously track the target's position and status until another target is located.
Unloading: The tracking target is unloaded from the tracker, and the tracker no longer tracks the target. This occurs when the session stops or the target is set to not use the tracker.

Table of Contents

Add Mega Tracking Targets

Before You Start

Note

Mega's Tracking Target

Note

Create Tracking Targets

Important

Tip

Tip

Note

Tip

Configure Tracking Targets

Configure the target data source

Tip

Configure the Tracker Used by the Target

Note

Tip

Warning

Tracking the Lifecycle of a Target

Next Steps

Table of Contents

Add Mega Tracking Targets

Before You Start

Note

Mega's Tracking Target

Note

Create Tracking Targets

Configure Tracking Targets

Configure the target data source

Tip

Configure the Tracker Used by the Target

Note

Tracking the Lifecycle of a Target

Next Steps

Related Topics