Thanks so much! :D

This helped me as even with having only one model target (and no other targets, not event the mars sample even present in the unity project) nothing got activated (licence, latest tools, everything checked). 

Only activating on load with your script helped :/.

Hi, is there anyone that has been able to replicate this code for Vuforia 10? I am new to vuforia and struggling to turn this example code into Vuforia10.

I'm having a lot of trouble trying to scale my project up from 1 model target to 3 (or even 2) to be detected one at a time.

When I try adding more than one model target I get this "Exception in callback: Failed to activate observer for behaviour "myTarget"".

I was hoping to fix it with some dynamic loading and activating but am new to both Vuforia and Unity and am having trouble adjusting this code to Vuforia10.

Hope someone can help me or direct me to the right place to ask if it's not here. Thank you!

 

I'm using Vuforia 10.2 in Unity 2020.3.19f1 

Attached is a picture of the error message.

Hello,

Untrained Model Targets only supports the detection and tracking of a one (1) Model Target at a time: https://library.vuforia.com/model-targets/how-create-model-target

If you're looking for the ability to package multiple Model Targets in the same device database, you can use Advanced Model Targets. However, this still has the same limitation as it can only track a single Model Target at any given time, but it can detect multiple Model Targets: https://library.vuforia.com/model-targets/advanced-model-target-databases

I strongly suggest that you closely review our free Unity Core Samples for best coding practices when using Untrained Model Targets and Advanced Model Targets: https://assetstore.unity.com/packages/templates/packs/vuforia-core-samples-99026.

Thanks,

Vuforia Engine  Support

Thank you for your help! I have gone over to using Advanced Model Targets, but still it doesn't seem like it is possible to recognize several model targets even though I just need to recognize one at a time. I am wondering if maybe there is something I am missing in this definition of what is possible: What is the difference between tracking and detecting? I only need to recognize one model target and perform a full screen action (play a video) and then if another model target appears when back in main screen (after the video), switch to that. I have no need for several at the same time but then how do you switch between them if you cannot track them all at the same time? When I try using more than one model target in my program it will only detect the first one in chronology in Unity, the others are initialized, but never tracked/detected.

By the way, the second link you sent does not work.

Hello,

anagrams wrote:

I am wondering if maybe there is something I am missing in this definition of what is possible: What is the difference between tracking and detecting?

Detection is an object being "found" by Engine SDK in the camera's field of view (FOV), and returning an initial 6DoF pose. Tracking is the continued, real-time return of 6DoF poses from the object that was detected. Note that detection usually takes 1-2 camera frames (very brief), while tracking is continuous while the object is in the camera's FOV.

In the case of Advanced Model Targets, several Model Targets can be bundled into a single device database. When that database is activated, Engine SDK will try to detect all the targets in that database. However, once a target from that set is detected, only one of the targets can be tracked at any given time.

anagrams wrote:

I only need to recognize one model target and perform a full screen action (play a video) and then if another model target appears when back in main screen (after the video), switch to that. I have no need for several at the same time but then how do you switch between them if you cannot track them all at the same time? When I try using more than one model target in my program it will only detect the first one in chronology in Unity, the others are initialized, but never tracked/detected.

My understanding is that you can only activate a single device database containing Model Targets at any given time. Untrained (non-Advanced) Model Targets can only have one object in the device database. Trained (Advanced) Model Targets are recommended for a maximum of 20 objects.

It sounds like a decision on how to create the UX. You could have the user actively select the object and thus you'd activate the corresponding Untrained device database, or you can use a trained device database that contains multiple objects. The SDK will 'detect' the targets in the camera's view, and then it is up to application logic on which one to track.

This use case is covered in the Core Samples (corrected link below), so I suggest your review that Unity Project for more details.

anagrams wrote:

By the way, the second link you sent does not work.

Thanks. Looks like the ending period was included in the URL. Please try this:

https://assetstore.unity.com/packages/templates/packs/vuforia-core-samples-99026

Thanks,

Vuforia Engine Support

Thank you so much for your answer!

I think it's getting clearer how targets work, but to be honest the Vuforia Core Samples are kind of daunting. Working with Trained (Advanced) Model Targets it's difficult to understand how to switch focus from one target to another when a target has started being tracked. If I code Destroy(firstTarget) after being finished with actions related to firstTarget, it will disengage firstTarget so that I can continue looking for the other targets, but then how do you initiate the same target again? And is there maybe a way to disengage a tracked target without having to destroy the gameObject?

Hello,

Unfortunately, it doesn't sound like the current implementation of Advanced Model Targets can meet your use case. When saying this, I'm referencing the following article: https://library.vuforia.com/objects/model-targets-api-overview

In particular, the following paragraph:

"As long as an Advanced Model Target is _TRACKED, recognition is disabled automatically to save processing power and prevent unwanted activation of other targets. When tracking of a Model Target is lost, i.e. its pose status changes to _EXTENDED_TRACKED or _LIMITED, recognition is automatically enabled again to allow detection of other activated Model Targets (or to relocate the current model target). Since only a single Model Target can be actively tracked at a time, a recognition and activation of another Model Target can lead to complete tracking loss of the previously tracked Model Target."

What this is saying is that you cannot detect another Model Target while actively tracking the first. Thus, as long as the first object is in the camera's field of view (FOV), no other objects can be detected. However, if the first object leave's the camera's FOV, resulting in a pose status change from _EXTENDED_TRACKED or _LIMITED, the event handler will report this and it can be handled at the app layer accordingly.

Thanks,

Vuforia Engine Support

Hi

I'm looking for a solution to load a dataset which was createt with the Model Target generator dynamicly at runtime from a webserver.

Is there any Example which solves a similar problem?

I'm using the unity SDK v.10.2.

Thank you in advance.

Hello @pbfhnw,

Vuforia Engine provides APIs for this very use case, but there is currently no working sample code that we provide that demonstrates it.

Unfortunately, Engine also does not provide a CMS service to manage device databases, including Model Targets. Thus, you'll have to build this service yourself or use another solution.

Once you have a way to get the Model Targets device database's DAT and XML files downloaded to the device (using the aforementioned CMS service), it is then just a matter of using Engine APIs to load it.

I suggest you review the following articles for more information:

    https://library.vuforia.com/getting-started/vuforia-engine-10-api

    https://library.vuforia.com/getting-started/vuforia-engine-api-unity

    https://library.vuforia.com/project-migration/how-migrate-unity-project

Thanks,

Vuforia Engine Support