Not sure what version of Vuforia - is there a way to check this in the unity editor?

I don't think so, but you can find the PostProcessBuildPlayer script in Assets/Editor and it should have a date of July 2013 for the latest.

N

"ReadPixels was called to read pixels from system frame buffer, while not inside drawing frame." This causes the webcam texture to become black"

Unity 4.2

Win 8 & Mac

Not sure what version of Vuforia - is there a way to check this in the unity editor?

with android free I get the error

....and fully describe exactly the problem you have along with the version of Unity/Vuforia/OS/etc. and anything else that you can think may help us to diagnose the problem.

N

I belivee this has to do with the latest Unity update (4.2), I asked someone to compile who had Android PRO license and it worked fine, with android free I get the error (where I didnt in the previous version of Unity)

This is confusing.

Could you please create a new thread for this issue and fully describe exactly the problem you have along with the version of Unity/Vuforia/OS/etc. and anything else that you can think may help us to diagnose the problem.

N 

The problem is this error: "ReadPixels was called to read pixels from system frame buffer, while not inside drawing frame." This causes the webcam texture to become black.

Any updates on how to resolve this issue?

elecman wrote:

vbox wrote:

I don't have a Unity 4 license available. Sorry.

Unity 4 Android and IOS is free now. Download the free version of Unity 4 and you will see that you can export to mobile devices.

This is indeed true, but the webcam mode requires Unity 4 Pro.

vbox wrote:

I don't have a Unity 4 license available. Sorry.

Unity 4 Android and IOS is free now. Download the free version of Unity 4 and you will see that you can export to mobile devices.

I don't have a Unity 4 license available. Sorry.

Does the same thing happen with Unity 4?

N

The same happens here on one of two Mac Minis with Unity Pro 3.6 when developing for iOS or Android.

I get the same error - 

Using macbook pro with mountain lion - i've just followed the instructions to create a simple project so all that is in it, is the camera, one target with a cube as a child. If i try to run on the player with IOS target - then this error occurs and it breaks - 

switching target to Mac,Pc etc... is m only workaround at the moment..

I get the same problem when using the Unity Android Player and Logictech HD Webcam C310. I solved it by switching back to the "PC, Mac & Linux Standalone" player. This is a bit annoying though as I'm developing for mobile and to have to switch back to the PC player to avoid this error is time consuming as Unity likes to waste its time reimporting every single asset :(

@thePostFuturist,

That doesn't cause the problem for me so there must be multiple causes of this bug.

Edit: 
That fix seems to work afterall. I just had to click "Switch Platform" after I selected "PC, Mac & Linux Standalone" in the build settings.

If you can provide detailed steps so I can reproduce on a Macbook using Image Targets as an example, then I will try and get something done about it.

many thanks

N

As I stated before I had the same bug - and I believe it is rather widespread, however, easily remedied via a hack:

WebCam mode will not work if you've "Switched Platform" to iOS. Switching to Desktop Publishing will once again make it functional.

Quote:

 Do you see the same issue on one of our sample projects (e.g. imagetargets) after a while?

I didn't see that happening yet.

Quote:

does your app include any additional render to texture functionality or have you done anything to force the rendering order of the objects in the scene (e.g. using Material.renderQueue)?

None of that. In any case, if I export my project to a unitypackage and then import it again in a new empty project, the problem disappears so the cause of the error can't be my code.

Edit:
I fixed it by exporting my project and importing it again. I suppose the only way to fix the error apart from re-importing the entire project is by figuring out what I did to break it. I will let you know when I figure out how to reproduce the error.

Hi elecman,

I would like to investigate this, but unfortunately I cannot reproduce this issue, your project works fine on my setup (Win 7, Unity 4 Pro, external webcam).

Do you see the same issue on one of our sample projects (e.g. imagetargets) after a while?
If not, does your app include any additional render to texture functionality or have you done anything to force the rendering order of the objects in the scene (e.g. using Material.renderQueue)?

The problem is not this error "Screen position out of view frustum". That error is indeed harmless.

The problem is this error: "ReadPixels was called to read pixels from system frame buffer, while not inside drawing frame." This causes the webcam texture to become black.

I don't know how to reproduce this error using a step by step procedure. Hopefully you can use my project to reproduce this error. Here is the link:
http://pilotpage.monosock.org/fileadmin/hidden_files/VuforiaUCSbug.rar

OS: Windows 7

Webcam: 1.3M HD Webcam (buildin from Acer Aspire 4743G laptop)

Game engine: Unity 4.0 pro

Open the project and navigate to the Scenes folder. Open up scene "VuforiaFrameMarkersRuntime" and hit Play. Hopefully you will see a black screen instead of a webcam texture.

Note that the project contains some missing scripts but these are 3rd party scripts which I removed. It doesn't affect the bug.

You should be able to avoid this error by keeping your mouse pointer above the scene view until play mode has fully initialized. This is a known issue that arises when a mouse event occurs on the stage before the scene is configured. Though it shouldn't corrupt your scene, I've never seen that occur. Typically the error is thrown, but is of no consequence. 

As Nalin's requested, please describe your dev environment, including Unity version and the camera you're using. 

Ok thanks elecman,

Do you have any concrete steps to reproduce?

If not then would you be able to upload the project somewhere so I can download and investigate further?

BTW is this Windows or Mac, and which webcam are you using?

thanks,

N

Same issue, "Error pause" doesn't resolve it.

"Error pause" is unchecked. Play mode doesn't crash or freeze but the video background is black. The textureBufferMesh in the editor shows the correct realtime webcam texture but the plane mesh (child of the BackgroundCamera) is black.

Have you by any chance got "Error pause" checked in the console.  If so then try unchecking this and see if the playmode continues.

If it is what I think it is then it will hopefully be a harmless error message.

N