Log in or register to post comments

3D object dissolves, when increasing distance to trackable

April 21, 2012 - 6:38am #1

Hi everyone,

I'm developing an application based on the ImageTargets example.

I noticed, that the rendered 3D object dissolves when increasing the distance to the trackable. Have you also run into this problem and maybe solved it?

Just for the record, the object doesn't disappear at once, so I don't think it's because of the tracking system losing the trackable.

Thanks in advance,
Felix

Re: 3D object dissolves, when increasing distance to trackable

April 23, 2012 - 2:00pm #6

Yeah!

This is it. Thanks a lot. My view distance has increased to about 1.5m. Great! :)

Re: 3D object dissolves, when increasing distance to trackable

April 23, 2012 - 11:37am #5

Look for the call to QCAR::Tool::getProjectionGL in ImageTargets.cpp. The numbers passed in are the near and far clipping planes. Try changing the second value to something bigger.

Another option is to make the size of your target smaller. You can edit the config.xml to change the size, the samples use a target width of about 250. Be sure to maintain the aspect ratio of the target when changing these values.

- Kim

Re: 3D object dissolves, when increasing distance to trackable

April 22, 2012 - 11:33pm #4

Hi,

I also have an issue with dissolving.

I can move away from the target about 30cm, when the 3D object starts to disappear partially. I searched through the forums and found some threads where the clipping distance of ARCamera is mentioned. But I wasn't able to find such a property in the framework...

Thanks
Alex

Re: 3D object dissolves, when increasing distance to trackable

April 21, 2012 - 8:56am #3

Yes, that's exactly the behavior I noticed.

This also happened with the original ImageTarget example, the wooden chips trackable and the the teapot.

I'm just wondering at the fact, that the object sinks into the target continuously instead of flipping around or something unexpectable. I would have guessed that there exists an (intended) threshold, above which the object would not be rendered anymore.

Using a larger physical target isn't an option, because its a climbing wall, thus not scalable by myself :)

It isn't a big problem at all, I was just curious to find out if there was an option to increase this distance.

The SDK I'm using is the most recent one.

Re: 3D object dissolves, when increasing distance to trackable

April 21, 2012 - 8:35am #2

Do you mean that the model seems to sink into the target?

That may be an anomaly that arises from the nature of the image that you're using. As you increase the distance to the target, the set of features apparent to the camera will change, simply due to the fact that the target appears proportionally smaller, and this can result in unexpected behavior.

There is a limit to the distance at which any target can be detected and tracked. You can increase this by using a larger physical target. You can also experiment w/ various modifications to the image. Feel free to post, or PM, a picture of your target for some advice.

And be sure that you're using a current version of the SDK.

Log in or register to post comments