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Potential Bug

May 23, 2012 - 4:43pm #1

Hi guys, I've found a bug with Frame Markers. If you change the marker id, the internal TrackableName property is not updated to accurately reflect the new marker id. This means that you can have multiple frame markers that have different marker ids, but Vuforia will fail to function because it will look at the duplicate trackable names and fail fast.

Now, how do TrackableNames get set to the same thing in the first place? This seems to have to do with copy/paste, but unfortunately I cannot give you reproducible instructions.

I have modified the following code in MarkerEditor.cs:

            if (newMarkerID != mb.MarkerID)
            {
                mb.MarkerID = newMarkerID;
                mb.TrackableName = "FrameMarker" + newMarkerID;
            }

This will fix the issue by keeping the TrackableName up to date with the marker id.

Potential Bug

December 12, 2012 - 12:36pm #13

Thanks Stan

Just to let you know this will not be fixed in the forseeable future.

N

Potential Bug

December 12, 2012 - 2:34am #12

Hi Guys, just to note, using latest vuforia 1.5.10 for android and unity 3.5.2 and issue is still there.

 

Re: Potential Bug

June 1, 2012 - 7:44am #11

Hi pushxtonotdie

Thanks for this - I was able to reproduce it.

We will investigate further.

N

Re: Potential Bug

May 31, 2012 - 12:31pm #10

Hello,

I have found reproducible steps regarding this issue without using copy/paste.

1. Create a frame marker by dragging it into the hierarchy. It will be given the default name FrameMarker0 and ID 0.
2. Change the name to FrameMarker1 and ID 1;
3. Drag another frame marker into the scene. It will be given the default name of FrameMarker0 and ID 0.

This will cause the internal variable name 'TrackableName' of both game objects to have the same value.

How I came to this issue:
I have scenes where there is no marker id 0. So I must change the marker id to, say, X and I rename it. And so I must have done the above step at some point and screwed up my scene.

Thanks,
C

Re: Potential Bug

May 29, 2012 - 1:25am #9

Hi pushxtonotdie

Thanks for the suggestion.

We'll look into this.

N

Re: Potential Bug

May 25, 2012 - 6:46pm #8

Hi Nalins,

I understand that you're supposed to drag prefabs in to the interface, and I understand that I reproduced the bug by a method that is not the expected method of use. I have encountered this issue without copy/paste, but I'm unable to reproduce, which is why I brought up the copy/paste method.

Also I think being able to copy/paste and modify the marker id is a useful workflow that could be added. Even if there wasn't the aforementioned bug, it is usually expected to be able to copy and paste items without issue.

Thanks,
C

Re: Potential Bug

May 25, 2012 - 6:30am #7

Hi pushxtonotdie

I downloaded your project and was able to reproduce the issue.

However it seems that the correct way to add new image markers is to drag the prefab from the project into the hierarchy, as per the online docs under Using Trackables \ Using Frame Markers:

"Make sure that each FrameMarker in your scene has a unique ID. As you drag out new instances of the FrameMarker prefab, they are automatically given the next highest marker ID."

Basically if you drag it out as a prefab it works fine, but not if you try to duplicate an existing Frame Marker.

HTH

N

Re: Potential Bug

May 24, 2012 - 10:29am #6

Ooooh, unity version? I thought you meant vuforia version. :) I'm running Unity Pro 3.5.1f2

DavidBeard wrote:

Thanks. I'll look into this.

You can find your Unity version under Unity > About Unity from the Menu Bar.

Re: Potential Bug

May 24, 2012 - 10:26am #5

Thanks. I'll look into this.

You can find your Unity version under Unity > About Unity from the Menu Bar.

Re: Potential Bug

May 24, 2012 - 9:44am #4

http://enemyhideout.com/vuforia/vuforia_trackable_name_bug.zip

I've determined some reproducible steps: copy/paste a frame marker. You'll notice that the marker's id is set to 1 and the name has been modified to FrameMarker1:

https://skitch.com/robotron2086/8hcjx/untitled-unity-pc-and-mac-standalone

This will not display the sphere shown, because, as you can see at the bottom of the screenshot:

Duplicate Trackables detected: "FrameMarker0". Only one of the Trackables and its respective Augmentation will be selected for use at runtime - that selection is indeterminate here.

The FrameMarker1's 'TrackableName' property is still set to FrameMarker0, and so it will not display a sphere, but instead the cube at runtime. And since there is no way to set this at runtime (and its most likely something you don't want users to update), the code above has fixed the problem for me.

Re: Potential Bug

May 24, 2012 - 9:21am #3

Where can I find the version number? I am assuming version 1.5.9, as I downloaded the package a couple weeks ago. I will attempt to recreate the bug and I will put up a tarball for you with the issue.

Re: Potential Bug

May 23, 2012 - 7:28pm #2

Which version of the Unity extension are you using?

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