Indoor 3D Reconstruction with Google Project Tango

·Abstract:

Real-time 3D scanning is an essential tool for fields like interior design, archaeology, and virtual reality. Compared to traditional 2-D images/videos, a generated 3D model provides better representation of surrounding environments for it provides not only images but also depth information. Commercial 3D Scanners are often expensive and bulky, and require a separate apparatus for storage and processing. But this project will seek a possibility to assemble a reasonable 3D environmental reconstruction solution with a Google project Tango development kit and a custom designed platform.

·The project Tango development kit:

The Google Project Tango (Tango for short) provides a new possibility for 3D space sensing. Tango is a device (an android tablet) equipped with various sensors to obtain its position, pose, and surrounding information without using GPS or other external signals. It uses Inertial Measurement Unit (IMU) to keep track of its motion in the full six degrees of freedom. It uses active laser to measure the surface orientation and distance of objects in the view. By combining more than thousands sets of point with surface orientation and distance informations collected from the laser sensor, the device could generated a “Point cloud” data. It provides Java APIs (an extension of Android APIs) to allow quick development of apps for the device.

·What is a “Point cloud” ？

# the Project Tango development kit

A typical Point cloud, by definition is a set of data points, which contains 3 dimensional (often a coordination in a specific coordination system) or multidimensional information. Usually if contains the external information of an object.

# A typical point cloud example

·”die Plattform”- a custom platform

In order to gather relatively stable point cloud during a scanning process, a platform was designed to commence the scanning manoeuvre. “die Plattform” is an Arduino powered platform that holds the tablet and rotates it around horizontal (X) and vertical (Y) axes. Two step motors powered by an Arduino is used to provide rotation at 90°increment in the Y-axis and 30° increment in the X-axis. A full scanning manoeuvre contains three 360°(around Y-Axis) scanning at angle of 0°, 30° and -30 °

# “die Plattform”

·How the project works?

During a rotation of the Tango device, “der Konstruktor”, which is an custom android application, will judge its rotation angle around Y-Axis which comes from Tango’s IMU. It will captures 6 sets point clouds during every round of scanning. After 3 rounds of scanning was finished, the application commences Delaunay Triangulation to the point clouds and draw them to the device screen.

·Results

# a picture of a scene

# The reconstruction of (part of ) the scene by the app

This work was supported by NSF grant CCF-1421734.

Yihe Chen (Advisor: Toshiro Kubota)Department of Mathematics