NEW!  Version 3 of iPi Motion Capture is available. iPi Motion Capture 3 delivers new features for improved workflow including support of Kinect 2, improved arms tracking, simplified calibration and others. Read more >>

This documentation corresponds to version 2 of iPi Motion Capture. The latest documentation for version 3 can be found at https://docs.ipisoft.com/

Cameras and accessories

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You can order software and hardware as one package from CamVFX, our official US Reseller.

Alternatively, you can select and order items you need separately.

Contents

Cameras

Recommended camera for use with iPi Motion Capture is Sony PlayStation Eye for PS3.


Playstation eye small2.jpg

The following properties make it a preferred camera for motion capture:

  • High frame rate — up to 60 frames per second (important for reducing motion blur and capturing fast motions like dancing, boxing or running).
  • Fully automatic configuration with excellent auto-exposure and auto-gain.
  • Very good low-light sensitivity.
  • Low-distortion wide-angle fixed optics.
  • Efficient protocol for image transfer (saves more than 50% of USB bandwidth when compared to other webcams).
  • Low cost (under $40).

The only downside of PlayStation Eye is its lack of tripod mounting screw. A possible solution is to use sticky tape to fix it to tripods.

You can use other webcams with iPi Motion Capture but please be aware that most webcams are not capable of capturing video at frame rates higher than 15 frames per second. Some webcams like Logitech Webcam Pro 9000 can reliably capture video at 30 frames per second.

Cables

For distances over 5m, you should use active USB 2.0 extension cables. You can daisy-chain multiple active USB 2.0 extension cables for distances longer than 10m.

Active USB cable.jpg

When combining active and passive cables, make sure that connection order is correct (computer->active cable->passive cable->camera).

Tripods

Inexpensive 40- or 50-inch tripods like [1] should be fine for use with iPi Desktop Motion Capture. It is recommended to place at least one of the cameras reasonably high (2 or 3 meters high) so you may need a high (72 inch or higher) tripod like [2] or some kind of ad hoc wall mounting solution.

Tripod.jpg

Mini Maglite (or other flashlight) for calibration

You will need a small bright object for calibration. It is recommended to get Mini Maglite (or other similar flashlight) for that purpose.

Maglite.jpg

Video Card

iPi Mocap Studio relies on GPU for calculations. Therefore, it is recommended to use a fast GPU for processing recorded videos. As a minimum, you need a Shader Model 4.0-compatible (DirectX 10-compatible) GPU. Intel integrated graphics is not supported

Please be aware that desktop GPUs are dramatically faster than laptop GPUs (due to apparent thermal constraints in laptop PCs). Laptops with switchable graphics should be configured to run iPi Mocap Studio on a discrete (high-performance) GPU.

You can check expected tracking speed for various GPU model here.

You can Compare and Order recommended GPU from Amazon.

Professional GPUs like NVIDIA Quadro or ATI FireGL are not recommended due to high price and lack of performance advantage. You should understand that Quadro/FireGL video cards are designed for very specific professional OpenGL-based workloads. Their main advantage is high image quality in OpenGL rendering. iPi Desktop Motion Capture needs raw 32-bit floating point performance and does not benefit from image quality features of Quadro/FireGL video cards. For best performance, use top gaming-class NVIDIA GeForce or ATI Radeon video cards.

USB controllers

All modern computers (e.g. dual-core and better) based on Intel, AMD and Nvidia chipsets have two high-speed USB (USB 2.0) controllers on board. That should give you enough bandwidth to be able to record with:

  1. 2 depth sensors (MS Kinect, or ASUS Xtion, or PrimeSense Carmine)
  2. or 4 cameras at 640x480 (raw Bayer format) at 60 FPS
  3. or 6 cameras at 640x480 (raw Bayer format) at 40 FPS.


You can check how many USB 2.0 controllers you have in the “Universal Serial Bus controllers” section in Device Manager. Operating system will display USB 2.0 controllers as “USB Enhanced Host Controllers” (not to be mistaken with USB 1.0 “USB Universal Host controllers”).

USB controllers.png

Alternatively, you can use USBView utility from Microsoft which allows to view all USB controllers and devices in a more convenient way: Download USBView

You should make sure that you have depth sensors or cameras evenly distributed between available USB 2.0 controllers. For example, if you have 4 cameras, you should connect 2 cameras to first controller and 2 cameras to second controller. Device Manager usually shows USB cameras as “USB Composite Device” at the “Advanced” tab of USB controller properties. If you have too many cameras connected to single USB 2.0 controller, you should re-plug them to different USB ports.

USB hubs

If several devices are connected on the USB hub and working in parallel, then the USB bandwidth is shared among the devices. Connecting all cameras via single USB 2.0 hub is OK only for low resolution video recording (320x240). To be able to record video at 640x480 and 60 frames per second, you should avoid connecting more than 2 cameras via single USB controller.

Potential issues with USB controllers

Some USB chips have compatibility issues with specific cameras which may result in not detecting cameras, low frame rate, etc. See the next section on known issues.

Many modern laptops have one of the integrated USB 2.0 controllers reserved for docking station. That may effectively halve your USB bandwidth. So laptops with a large number of USB ports (4 or more) are preferrable. Desktop PCs should not have such problem.

Important. Before buying a specific laptop model it is strongly recommended to ensure it has the sufficient number of available built-in USB controllers and they are compatibile with cameras you intend to use. Find it at your local retailer, and bring cameras with you to test. Though it may be easier if your friend/neighbour has such a laptop. Or ask at our forum, maybe someone already used this model with our software or can recommend specific model for your camera configuration.

If you plan getting an additional USB controller, please be aware of potential problems with USB 2.0 controllers available on the market. Many USB 2.0 controllers are based on defective NEC USB 2.0 chip, not capable of standard USB 2.0 speeds. That's a well-known bug specific only to NEC USB 2.0 chip. By contrast, all NEC USB 3.0 chips are good and do not have this problem.

Some manufacturers sell what they call a "USB 2.0 ExpressCard" controller for laptops. Many of such ExpressCard controllers are in fact internal USB hubs in ExpressCard form factor. That means they do not add actual USB bandwidth to the system. All USB 3.0 ExpressCard are controllers.

If you plan getting additional high-speed USB controller, we strongly recommend that you get a USB 3.0 controller, just to be on the safe side.

When setting up a USB 3.0 controller, make sure you configure it to handle USB 2.0 traffic (as opposed to passing USB 2.0 to integrated USB 2.0 controllers in your chipset). There should be a corresponding setting in driver properties or in BIOS.

Known compatibility issues

Combinations of camera & USB chip listed below have known compatibility issues. Unfortunately, there is no guarantee that other combinations will work for sure, but most will. If you need an additional USB controller for connecting specific camera, be sure not to get the one based on incompatible USB chip.

Camera USB chip Symptoms Comments / possible solution
ASUS Xtion (Live) NEC µPD720200 (USB3) Camera is not properly recognized by the system. This firmware update makes device behave the same as PrimeSense Carmine 1.08 with this controller.
ASUS Xtion (Live) VIA VT6212L (USB2) Frame drops of color picture in 640x480@30 (depth + color).
PrimeSense Carmine 1.08 NEC µPD720200 (USB3) Frame drops in 640x480@30 (depth + color). Stable work in 640x480@30 (depth only) and 320x240 (depth + color).
PrimeSense Carmine 1.08 VIA VT6212L (USB2) Frame drops in 640x480@30 (depth + color). Stable work in 640x480@30 (depth only) and 320x240 (depth + color).
PrimeSense Carmine 1.08 VIA VL800(USB3) Frame drops, reduced frame rate, freezes in depth + color modes. Stable work in depth only modes.
Sony Playstation Eye VIA VL800 (USB3) Great number of bad frames and frame drops. Camera is invisible to iPi Recorder.
Sony Playstation Eye VIA VT6212L (USB2) Great number of frame drop in 640x480@60 mode. 2 cameras can work smoothly at lower FPS (up to 640x480@50).
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