Do you like the digital version of me in the picture above? It is a screen shot from my new dual Kinect setup in DBG Studios for the sci-fi fighting game, Future Fighter (TM). That's me in the middle standing behind and holding a big'ol white calibration board. While this particular take was a success, the initial setup of the dual motion sensors was not. In fact, I failed miserably because I couldn't get my Kinects to calibrate in the software, iPi Soft Mocap Studio. No calibration means no motion capture, and no motion capture means no kung-fu moves for the game!
Luckily I found the secret to success: sensor positioning. If the cameras' actual depth sensors (the little red cameras on the Kinects) are the proper distance from you, the proper distance from each other, inline with each other, and pointed at the correct angle then you get a successful calibration each time. In the software, this is either a "Good" or "Perfect" rating. The best part about this method is that it only requires a short calibration video. This leaves more time for capturing the actual moves.
Since this took so many trial-and-error sessions to figure out, I thought I would create a handy reference for the motion capture community to save everyone some time. So your free-download-with-every post is finally here! Below, you will find detailed tips to incorporate into your calibration setup and procedure for iPi Soft Studio. Once setup, the video will show you the proper motion for your calibration board to achieve success in a short amount of time. Use the links below to share it widely with your friends who may be looking to create or already have a dual-depth sensor setup.
TIPS FOR SETTING UP AND CALIBRATING DUAL-KINECTS FOR IPI SOFT STUDIO:
TIP 1: SET THE SAME VIEWING ANGLE FOR EACH SENSOR
1. Open iPi Recorder. Make sure your depth sensors are selected and click "Record Video."
2. Put your mouse in the left viewing window and set the elevation angle to 0.
3. Repeat for the right.
4. Leave this program up and running while you do Tip 2.
TIP 2: PUT THE DEPTH SENSORS OF THE KINECTS (THE RED SENSORS) IN THE RIGHT POSITION AND AT THE RIGHT ANGLE
1. Approximate the positions of the cameras as seen in the documentation diagram. Don't worry about being too exact because we're going to move things around in a bit.
2. Go to your capture point. It's the yellow circle in the aforementioned documentation diagram. This should be approximately 10-11.5 ft from the camera on your left and on your right.
2. Turn to your right camera and walk to it. Now, align the motion sensor (the red sensor) with the center of your body. Make the T-bar of the Kinect perpendicular to the line you just walked towards it. While still facing the camera, walk that line backwards to the capture point.
3. Looking back and forth at the left and right cameras, imagine a line running from one depth sensor (the red camera) to the other. Find the mid point in that line and line yourself up with it. (If it helps, back up a bit to more easily do this.) You will likely either be a little to the left or right of your capture point.
4. Now walk up to the camera on your left. If you were a little left of your capture point move the entire Kinect to the right, and vice versa if you were a little right. Remember to always move the Kinect by the base as per the Kinect documentation.
5. Now go back to the capture point and repeat step #3. Keep repeating that step until you finally end up at the capture point! Make sure to try and keep the red sensors in a line with each other. This will help you be approximately the same distance from each sensor. Also, make sure you can walk the line from the capture point to the left sensor just like you did with the right in #2.
TIP 3: HOW TO MOVE THE BOARD WHILE CAPTURING YOUR CALIBRATION VIDEO
1. Hold the calibration board as far away from your body as possible so that its center is at the center point.
2. While twisting your waist from side to side, turn the board left and right like you are turning a steering wheel back and forth. Do this for about 5 seconds. 3. Keep twisting your waist, but now bank the board towards and away from you like a fan. Do this for about 5 seconds.
4. Load this video into iPi Soft Studio and follow the calibration process in the documentation. This should give you a successful calibration of either good or perfect. If it fails, record the same duration again, but this time move closer to the cameras. If that doesn't work, record the same duration again but move farther away from the cameras. If neither works, return to the original position but just record each segment for a longer duration -- say 10 seconds each. If none of the above works, your sensors are not positioned properly. Repeat TIP 2.