Log in or register to post comments

3D object position is not appropriate with marker

March 13, 2014 - 6:31pm #1

hello all...
i've tried to build AR android application with unity extension sdk, when i render my 3D object, it looks bad, when i move my camera the object also move.

i use the latest sdk and also checked the extended tracking fiture

attached image shows my problems, red point is my marker

AttachmentSize
Image icon 1.png452.68 KB

3D object position is not appropriate with marker

June 15, 2017 - 1:29pm #8

Hello,

From your description and attachment, I don't believe this is a 'model' issue. Rather, I believe the augmentation alignment (aka registration) and "wobble" (aka pose jitter) issues you're observing are likely a result of the distance of the marker from the camera.

The Vuforia SDK extracts feature points from the marker with each camera frame. Thus, the more distant the marker becomes from the camera, the more difficult it will be for the algorithm to provide an accurate pose. You can estimate the minimum size that your target should have by dividing your camera-to-target distance by ~10. For instance, a 20 cm wide target would be detectable up to a distance of about 2 meters (20 cm x 10). Note, however, that this is just a rough indication and the actual working distance/size ratio can vary based on lighting conditions, camera focus, and target rating.

The Extended Tracking feature can be used to supplement our 2D tracker's performance and overcome some of these limitations. It also extracts features, from the environment in addition to the target, so may help to stabilize your experience.

Thanks.

3D object position is not appropriate with marker

June 14, 2017 - 4:34pm #7

Has there been any update to this type of issue? We've noticed that when we use large objects they tend to be off in their alignment with the image target or wobble uncontrollably (erratically shaking). Small objects seem to be a little less problematic, but still suffer from alignment issues. See attachment. This object should be flat to the marker but seems to be rotated almost 90 degrees.

We're using 3DS Max for the modeling and Unity to display. This is consistent with all devices.

 

AttachmentSize
Image icon Snip.PNG77.57 KB

3D object position is not appropriate with marker

March 14, 2014 - 5:19am #6

My suggestion would be to try to import and re-export the model with a 3D software (like Maya, 3D Studio, Blender or similar tool); those tools allow you to check the model reference frame and to change it (for instance, there are re-centering options when exporting it).

But I'm not an expert of those tools either.. so mabe worth checking in other Forums too.

 

3D object position is not appropriate with marker

March 14, 2014 - 3:30am #5

ok ,thanks for your quick reply :)

by the way i'm newbie with this Augmented Reality, would you reccomend something to do with my problem or some reference or keyword that i can search and learn :D
 

thanks so much for your help :)

3D object position is not appropriate with marker

March 14, 2014 - 2:51am #4

This probably depends on how the model reference frame has been defined when exporting the model (mesh) from a 3D authoring tool; probably the centering of the model is a bit off, so the issue is not much about Vuforia. 

 

3D object position is not appropriate with marker

March 14, 2014 - 2:05am #3

yes, but first when i try to render my object with very small scale, it looks good, but when i increase the scale, something bad happen, sometimes my object rotate a couple of degrees or it's moving.

you can see my attached image.
 

3D object position is not appropriate with marker

March 14, 2014 - 1:28am #2

The screenshot shows that your marker is oriented with a very steep angle ((very oblique) w.r.t. the camera, so it is hardly visible; make sure the marker is well visible and in focus.

 

Log in or register to post comments