School of Science and Technology 科技學院
Computing Programmes 電腦學系

3D Show Flat Demonstration System of Residential Properties with Leap Motion

YUN Tim Chak

ProgrammeBachelor of Science with Honours in Computing
SupervisorDr. Andrew Lui
AreasInnovative Systems
Year of Completion2014


This project aims to provide visual aids for people who are potential buyers of residential properties. With Leap Motion, the flat can be presented in 3D that buyers can simply use their bare hands to control which side of the show flat they would like to see and interact with the 3D show flat system on a computer. Buyers can better visualize the details of the flats or apartments and conceive ideas of interior design. As the same time, the hygiene problem in the public first-sale site can be avoided.

To achieve the aims, the project objectives are described in detail below:

  • Develop a Tutorial System
  • Design a simple and clear Graphic User Interface
  • Integrate Leap Motion and the 3D Show Flat System
  • Design gestures for command that are easy to pick up
  • Develop interior designs of show flat Decoration with different styles.
  • Add and arrange furniture location according to buyers’ preferences.
  • Design interesting interaction to buyers that are similar to their real daily life activities.
  • Test and evaluation

Background and Methodology

Leap motion is a small computer sensor device which detects motion of hands, finger and rod shape materials without any hand touching that can avoid hygiene problem in public areas. It employs right-handed Cartesian coordinate system.

Leap Motion uses infrared optics and camera to do motion sensing. It does not cover a large area of detection when comparing with Microsoft Kinect. Detecting area is around one meter radius hemisphere. However, Leap Motion has high sensitivity. The cameras generate almost 300 frames per second of reflected data that it can detect small changes of your hands and fingers. Therefore, the Leap Motion is suitable for completing highly accurate actions such as changing location of objects in 3D world.

First of all, the system will start with tutorial part. Users should follow a specific gesture to start the system (hold up both hands with ten fingers).

At the beginning of the tutorial system, the users should set their handedness. They should put down the non-handedness hand and hold up another one. The gesture lets the system know which hand is the users’ handedness.

When the 3D Show Flat Demonstration System started, users can see a 3D virtual apartment on the monitor. Users can move their weak hand with index finger to left, right, up and down to change the view angles in the system. After chosen the path, users can hold their weak hand with five fingers to move forward along the path. They can hold their weak hand with no finger to move backward along the path.

Users can move the furniture position. First, they should change their view angles and let the center of the screen pointed to the furniture.

Users can hold their both hand with two index fingers and move their right index finger to relocate the position of the furniture.

Users can hold their both hands with no finger to put down the furniture. After that, the furniture should be relocated.


There were 10 testers to test the 3D Show Flat Demonstration System who are never use this system and Leap Motion. The testing duration was 15mins per one tester. They complete a questionnaire for giving us some comments. The following information is the result of the surveys and the comments from the testers.

Most of the testers think that the 3D Show Flat Demonstration System can improve the realization and visualization. Only 20% testers think that typical show flat is better that the system. 100% testers think that the system is better than floor plan and residential model. 100% testers agree the system promote the flat in a more interesting way. 100% testers agree this is a gimmick to sell properties. 100% testers agree the system can avoid the hygiene problem. 100% testers agree the gestures are easy-to-learn.

Some testers comment that the leap motion cannot detect the gestures. It is because the environmental factors to influence the detection. For example, the light intensity, color of the wall and so on. Some testers comment that they need a short period of time to learn how to use the Leap Motion.

In conclude, I can find out that the system can provide visual aids to buyers of apartments basically. This solution can solve the visual problems of the recent marketing strategies for selling residential properties.

Conclusion and Future Development

In this system, there are 6 main objectives I was satisfied. All of them are finished already. Here are details of the objectives following:

Objective 1 is 100% finished to provide a tutorial system to the users that learn the gestures and set their handedness.

Objective 2 is 100% finished to design a simple and clear GUI. The system provides a excellent 3D show flat with different kinds of furniture and different rooms. It improves the users’ realization.

Objective 3 is 100% finished. The integration between Leap Motion and the 3D Show Flat System was finished that user can control the 3D show flat by the Leap Motion Directly.

Objective 4 is 100% finished. Easy-to-learn gesture commands are designed well. Users can learn it from the tutorial system easily.

Objective 5 is 100% finished. Different kinds of interaction are implemented. Users can change the view in the show flat, move into different rooms and relocate the furniture.

Objective 6 is 100% finished to do performance evaluation by 10 users who never use the system and Leap Motion. I can know more about the limitation and understand more about the system.

Leap Motion is new technology that just a prototype detector. Lots of limitations come from it. The environmental factors are the main factors to limit my development of the system. For example, the light density, objects, color of the wall, reflective light from other objects and so on. They can affect the Leap Motion detection because Leap Motion predicts the position of the hands according to the reflective ultra-red light. The ultra-red light can be easy to disturb or absorb by different materials. Moreover, every object can release ultra-red light that the prediction of Leap Motion should be affected. It causes gesture overlapping easily that I cannot design complicated gestures and similar gestures. Moreover, Leap Motion cannot detect hand hanging or sticking up gestures due to the detecting limitation of the Leap Motion. Therefore, I can only design hand holding up gestures.

Copyright Yun Tim Chak and Andrew Lui 2014

Jonathan Chiu
Marketing Director
3DP Technology Limited

Jonathan handles all external affairs include business development, patents write up and public relations. He is frequently interviewed by media and is considered a pioneer in 3D printing products.

Krutz Cheuk
Biomedical Engineer
Hong Kong Sanatorium & Hospital

After graduating from OUHK, Krutz obtained an M.Sc. in Engineering Management from CityU. He is now completing his second master degree, M.Sc. in Biomedical Engineering, at CUHK. Krutz has a wide range of working experience. He has been with Siemens, VTech, and PCCW.

Hugo Leung
Software and Hardware Engineer
Innovation Team Company Limited

Hugo Leung Wai-yin, who graduated from his four-year programme in 2015, won the Best Paper Award for his ‘intelligent pill-dispenser’ design at the Institute of Electrical and Electronics Engineering’s International Conference on Consumer Electronics – China 2015.

The pill-dispenser alerts patients via sound and LED flashes to pre-set dosage and time intervals. Unlike units currently on the market, Hugo’s design connects to any mobile phone globally. In explaining how it works, he said: ‘There are three layers in the portable pillbox. The lowest level is a controller with various devices which can be connected to mobile phones in remote locations. Patients are alerted by a sound alarm and flashes. Should they fail to follow their prescribed regime, data can be sent via SMS to relatives and friends for follow up.’ The pill-dispenser has four medicine slots, plus a back-up with a LED alert, topped by a 500ml water bottle. It took Hugo three months of research and coding to complete his design, but he feels it was worth all his time and effort.

Hugo’s public examination results were disappointing and he was at a loss about his future before enrolling at the OUHK, which he now realizes was a major turning point in his life. He is grateful for the OUHK’s learning environment, its industry links and the positive guidance and encouragement from his teachers. The University is now exploring the commercial potential of his design with a pharmaceutical company. He hopes that this will benefit the elderly and chronically ill, as well as the society at large.

Soon after completing his studies, Hugo joined an automation technology company as an assistant engineer. He is responsible for the design and development of automation devices. The target is to minimize human labor and increase the quality of products. He is developing products which are used in various sections, including healthcare, manufacturing and consumer electronics.

Course CodeTitleCredits
 COMP S321FAdvanced Database and Data Warehousing5
 COMP S333FAdvanced Programming and AI Algorithms5
 COMP S351FSoftware Project Management5
 COMP S362FConcurrent and Network Programming5
 COMP S363FDistributed Systems and Parallel Computing5
 COMP S382FData Mining and Analytics5
 COMP S390FCreative Programming for Games5
 COMP S492FMachine Learning5
 ELEC S305FComputer Networking5
 ELEC S348FIOT Security5
 ELEC S371FDigital Forensics5
 ELEC S431FBlockchain Technologies5
 ELEC S425FComputer and Network Security5
 Course CodeTitleCredits
 ELEC S201FBasic Electronics5
 IT S290FHuman Computer Interaction & User Experience Design5
 STAT S251FStatistical Data Analysis5
 Course CodeTitleCredits
 COMPS333FAdvanced Programming and AI Algorithms5
 COMPS362FConcurrent and Network Programming5
 COMPS363FDistributed Systems and Parallel Computing5
 COMPS380FWeb Applications: Design and Development5
 COMPS381FServer-side Technologies and Cloud Computing5
 COMPS382FData Mining and Analytics5
 COMPS390FCreative Programming for Games5
 COMPS413FApplication Design and Development for Mobile Devices5
 COMPS492FMachine Learning5
 ELECS305FComputer Networking5
 ELECS363FAdvanced Computer Design5
 ELECS425FComputer and Network Security5