Depth Sensors Comparison

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Depth Sensors Support

iPi Recorder supports the following depth sensors:

Kinect 2 (Kinect for XBOX One)
Orbbec Astra (PRO)
Intel RealSense D415 and D435
ASUS Xtion 2
Microsoft Kinect for Windows
ASUS Xtion Live
ASUS Xtion
PrimeSense Carmine 1.08

First generation depth sensors are almost outdated but still usable. For example, Orbbec Astra (PRO) has totally the same depth quality and resolution as these outdated sensors. For this reason you can use for example MS Kinect v1 sensor(s) and get exactly the same results as with Orbbec Astra sensor(s). If needed you can find more information about these sensors in documentation for previous version of iPi Motion Capture.

As to modern depth sensors, MS Kinect 2 (Kinect for XBOX One) sensor remains the best choice for full body motion capture. The quality and accuracy of depth map from MS Kinect 2 are the best in market.

Important.png
Important! Only one MS Kinect 2 (Kinect for XBOX One) sensor can be connected to a single PC due to limitation in Microsoft Kinect SDK 2. Each MS Kinect 2 (Kinect for XBOX One) sensor can be connected to a separate computer, Distributed Recording feature must be used.

Comparison

Main features of depth sensors:

Place Sensor Price (approx) Technology Depth FOV (vertical) Depth Resolution Depth FPS Interface Multiple Sensors per single PC External Power Supply Tripod Mount
1 Kinect 2 (Kinect for XBOX One) $160 Time-of-Flight 60° 512x424 (very good quality!) 30 USB 3.0 no required yes (1/4″)
2 First-gen depth sensors from $30 Infrared Coded Structured Light 45° 640x480 (interpolated, actual: 320x240 or even less) 30 USB 2.0 yes not required (except Kinect v1) no
2 Orbbec Astra (PRO) $160 Infrared Coded Structured Light 45° 640x480 (interpolated, actual: 320x240 or even less) 30 USB 2.0 yes not required yes (M6 not 1/4″)
3 Intel RealSense D435 $180 Infrared Coded Structured Light combined with stereo RGB matching 65.5° (only 42° for RGB) up to 1280x720 (but very noisy, inaccurate and with a lot of artifacts like waves and blur!) up to 90 USB 3.0 yes not required yes (1/4″)
3 ASUS Xtion 2 $270 Time-of-Flight 52° (can be mounted in vertical position for 74°) 640x480 (interpolated: actual is less than 320x240) 30 USB 3.0 no not required yes (1/4″, dual at bottom and side)

Major Pros and Cons of depth sensors:

Place Sensor Pros Cons
1 Kinect 2 (Kinect for XBOX One)
  • Higher FOV
  • Higher resolution of depth and RGB video
  • Lower noise, better quality and accuracy of point cloud
  • Higher overall tracking quality can be expected
  • Much better feet tracking
  • Low mutual sensors interference
  • More tolerant to lighting conditions
  • Has mount for tripod
  • Doesn't like certain fabrics (e.g. shiny)
  • Requires USB 3.0 controller and external power supply
  • Only one sensor per single PC is supported by Microsoft Kinect SDK 2
  • Does not work on Windows 7 (requires Windows 8 and higher)
2 First-generation Depth Sensors
  • Ensures tracking quality comparable with that of Kinect 2, but hardware requirements are not so strong
  • Requires USB 2.0 controller
  • Multiple sensors can be connected to a single computer
  • Works on Windows 7 and higher
  • Lower FOV
  • Lower resolution
  • Lower accuracy
  • Less tolerant to lighting conditions
  • Higher mutual interference of sensors leads to more noise in case of using several sensors
  • No mount for tripod
2 Orbbec Astra (PRO)
See above (as 1st gen. depth sensors)
Plus:
  • On sale
See above (as 1st gen. depth sensors)
Plus:
  • Higher price compared to 1st gen. sensors
  • Non-standard tripod mount — M6 instead of 1/4″
3 Intel RealSense D435
  • Up to 90 FPS
  • High resolution of depth map
  • Good field-of-view (FOV)
  • Very compact
  • Great tech support, fast fixes, frequent updates
  • Very low quality of depth map (high noise, many artifacts)
  • Multiple sensor configuration is not practical with this sensors because of accuracy and quality of depth map (cannot be calibrated)
  • RGB camera has significantly lower FOV
3 ASUS Xtion 2
  • Time-of-Flight like Kinect 2
  • Good field-of-view (FOV)
  • Can be mounted in vertical position
  • Very compact
  • Extremely low effective resolution of depth map (too small amount of 3D dots)
  • No mapping between RGB and depth
  • Only one sensor per single PC is supported
  • High price

The winner is Kinect 2 (Kinect for XBOX One).

First-generation depth sensors and Orbbec Astra (PRO) share the second place.

Note about Intel RealSense D415 and D435

Based on specification Intel RealSense D415 and D435 sensors look very promising. Especially, D435 model which has wider FOV and slightly better quality of depth map.

But actual quality and accuracy of depth map from these sensors are way worse than what we could expect from modern depth sensors:

  • huge waves on relatively flat surfaces
  • thick blur around objects
  • extremely high noise both in spatial and time dimensions

These downsides make Intel sensors almost unusable for full body motion capture tasks.

For this reason we included only D435 model in comparison tables because it's more powerful and advanced compared to D415 but still is not good enough for our needs.

Drivers and Software Libraries

The following sensors don't require special drivers and software to be recognized in iPi Recorder:

  • Intel RealSense D415 and D435
  • ASUS Xtion 2

That is, you can simply plug in these sensors to computer and make recordings in iPi Recorder without need to install any drivers or SDK's.

Other sensors require special drivers and/or software libraries/SDK to be installed: