Skeleton Wizard problems

[EP78]

Hello,

we have recently started to work with an Optitrack 6-camera (V100:R2) MoCap system (Arena Bundle).

We have created a hexagon stage using the 6 cameras and have thus created an area of appr. 5 x 5 meters.

We were using an earlier version of Arena first (v 1.6). This worked pretty well, as we got only seldomly some red blinks on the 3D avatar. The only severe problem was that recording did not work, as the whole software would crash after a few seconds after clicking record (some V C++ error message occured).

So we upgraded the software to v 1.7.3. Now recording works, but we have severe problems with our skeleton. It looks totally messed up, meaning that the legs are somewhere around the head etc.

We were following the instructions in the youtube optitrack videos as usual (T-Pose for some seconds, then some movements, then picking a frame, T-Pose found, etc.) but when clicking to make the T-Pose fit to the avatar, a messed-up avatar appears, as described above.

As the only thing that changed in the meantime were the different Arena versions (1.6 vs. 1.7.3), we suppose it must have something to do with settings. But which ones?

Does anyone has a hint for us?

Many thanks.

Best,
Ben

[bsteagal]

Ben

The pointcloud engine changed from version 1.7.1 to 1.7.2, so to get the best results, go to the Pointcloud tab, and change the "min line" setting from 3 to 2, and see if that doesn't give you better results

5x5 meters, is that where you have the cameras setup at? or is that the actual volume that you are trying to capture? 5x5 meters is normally not really possible, as the max volume for the USB systems is about 3x3 meters (10 feet)

hope this helps

Bryan

[EP78]

Bryan,

many thanks for your fast reply.

5 x 5 meters does not refer to the captured volume but to the area that is built by the actual cameras. So measuring distance from one camera to the opposite one results in a distance of about 5 meters.

Actually, we had the problem of messed-up 3D figure before, when using the 1.6 Arena version. Then I re-arranged the cameras (just slightly but more accurate than before) and got almost perfect 3D figures. All this with v 1.6. Then the upgrade to v 1.7.3 and the 3D figures were messed up again.

But thanks for your hint, I will try ASAP if this works.

Best
Ben

[bsteagal]

Ben

That is what I thought, but just wanted to make sure! Are you using a 3 marker wand or 1 marker? just curious..

They've also made some new recommendations in regards to calibration.. Mike from NP recommends you first do the calibration in fast, wait till you get the best result (exceptional) and before clicking "apply", change the dropdown to "medium" and let it recalibrate until it hardly changes again, then change again to "high" and then "very high" ... each time you do this, it utilizes a different set of points, therefore giving you the best calibration possible.. takes longer, but gives very good results



Bryan

[EP78]

Bryan,

many thanks again.

It's a 3 marker wand we are using.

Best,
Ben

[EP78]

PS:

BTW, changing the "min line" setting from 3 to 2 worked pretty well for us. Thx for the hint.

Ben

[bsteagal]

You are welcome! glad to be of help...

[DonBurroni]

[quote=Bryan Steagall]Ben

That is what I thought, but just wanted to make sure! Are you using a 3 marker wand or 1 marker? just curious..

They've also made some new recommendations in regards to calibration.. Mike from NP recommends you first do the calibration in fast, wait till you get the best result (exceptional) and before clicking "apply", change the dropdown to "medium" and let it recalibrate until it hardly changes again, then change again to "high" and then "very high" ... each time you do this, it utilizes a different set of points, therefore giving you the best calibration possible.. takes longer, but gives very good results



Bryan [/quote]

This is gold, im going to try this tomorrow, im having trouble with expression at the moment

[NaturalPoint - Mike]

In our experience, it works best to start on medium and let it go until you have all exceptionals, then switch to high, let it go until all are exceptional, then switch to very high, and finally apply when they're all exceptional on VH. Our resident artist actually waits until the mean error on every camera is .089 or less before applying on very high, but this can take a long time with a good wanding sample, and be impossible with a lower quality wanding.

With expression, there's the added difficulty of wanding so close to the cameras. Is your custom wand active or passive? If it's active, disable the IR On the cameras. If it's passive, put them in continuous mode, and at 2 or 3 intensity. Either way, you'll have to calibrate at a very low exposure and work harder at it than you would with arena or tracking tools to get proper wanding coverage.

[DonBurroni]

My wand is passive, I've actually found it a little too small for calibration, I now have made a 25cm wond.

I have noticed it can crash expression when I go to close to the cameras sometimes.

Is there a way of wonding again and again to get better results?
Or do I just do the wand once and keep upping the solver....

'you'll have to calibrate at a very low exposure' you are right about this, and intensity I think my cameras have some how got brighter...

I now have to calibrate with an intensity of 1, I used to use 5-6. (with the same number of cameras)