Using game engine for physics

Using Game Engine for Physics-Based Simulation - a Forklift

使用遊戲引擎模擬物理現象: 堆高機

Using Game Engine for Physics-Based Simulation - a Forklift

使用遊戲引擎模擬物理現象: 堆高機

Related references

1. J. R. Juang, W. H. Hung and S. C. Kang, "Using Game Engine for Physics-Based Simulation - a Forklift," Journal of Information Technology in Construction, vol. 16, pp. 3-22, 2011.

2. Chan Y. C., Chen Y. H., Kang S. C. and Lee T. H. (2008). Development of virtual equipment for a hydraulic mechanics experiment, Tsinghua science and technology, Vol. 13, No. 1, 261-265.

3. Hung W. H. and Kang S. C. (2009). Physics-based crane model for the simulation of cooperative erections, Proceedings of 9th international conference on construction application of virtual reality (CONVR), Sydney, AU, 237-246.

4. Chi H. L., Hung W. H. and Kang S. C. (2007). A physics based simulation for crane manipulation and cooperation, Proceedings of computing in civil engineering conference, Pittsburgh, USA, 24-27.

5. Kang S. C. (2005). Computer planning and simulation of construction erection process using single or multiple cranes, Ph. D. dissertation, Stanford University, San Francisco, USA. 6. Kang S. C. and Miranda E. (2009). Numerical methods to simulate and visualize detailed crane activities, Computer-aided civil and infrastructure engineering, Vol. 24, 169-185.

Using Game Engine for Physics-Based Simulation - a Forklift 使用遊戲引擎模擬物理現象: 堆高機 施工建設作業的詳細模擬是一個具有難度的任務。製作物體的模型需要巨大的工作時數一步一步完成， 此外還需要相當龐大的計算量。本研究的目的是利用一個遊戲引擎，來減少所需的開發工作，遊戲引擎 在過去超過10年內一直是一個迅速發展的領域。透過鍵盤，用戶可以控制一個虛擬堆高機來模擬一個實 際的堆高機的操控。結果表明了以遊戲引擎來模擬施工的優勢。模擬的圖形擁有高品質的擬真度，且可 以讓使用者和電腦進行互動。 我們把建立使用物理引擎的模擬過程分為三個步驟：（1）建立3D模型，（2）設定物理參數來操控和 模擬現實生活中的物理現象，（3）建立完善的遊戲邏輯。這三個步驟都可以在Blender中，透過視覺化 的介面來完成。這減少了開發人員切換各種電腦工具的時間和精力，使他們能夠專注於模擬。在這項研 究中，我們使用這三個步驟來製造一個堆高機。我們發現與傳統的方法相比，使用的遊戲引擎具有五大 優勢：更容易開發，開發時間縮短，圖形質量更高，模擬更穩定，更好的即時互動。在未來，營建產業 應充分利用先進的遊戲引擎來開發更多使用物理引擎的模型，並建造一個標準資料庫。這將會提高使用 虛擬實境中模擬工地的好處，使他們能夠模擬物理現象。

Architecture of a game engine.

Authoring Tool Load game contents

Set physics features

Set game logic

Physics Engine

Rendering Engine

Audio Engine

User Interface

Collision Boundaries Collision Detection Rigid Body Dynamics Soft Body Dynamics Aerodynamics Collision Response

Objects Transform Lighting Calculation Viewing Transform Projection Rasterization

Load Sounds Play Sounds Mix Sounds Attenuation 3D Sounds Effect Doppler Effect Listener Settings

Control Triggers Interaction Triggers Key Settings Mouse Setting 2D Sprites

Using Game Engine for Physics-Based Simulation - a Forklift

The detailed simulation of construction operations remains a challenging task in construction practice. A tremendous number of laborhours are required to set key frames of an animation step-by-step and considerable computational power is needed to render an animation frame-by-frame. This research aims to utilize a game engine, which has been a rapidly evolving field for over a decade, to reduce the effort required by developers. With a keypad, users could control a virtual forklift to simulate the manipulation of an actual forklift. The simulation result shows the advantages of developing a game engine-based construction simulation. The quality of the simulation’s graphics provides a high degree of realism, and the interactivity requirements between user and computer are satisfied We separated the process of building physics-based simulations into three steps: (1) creating the 3D models, (2) specifying physics parameters to switch and control the realistic physics behaviors, and (3) setting up the game logic. These three steps can be completed using the visual programming interface embedded in Blender. This reduces the time and effort for developers to switch between various computer tools and allows them to focus on the simulations. In this research, a forklift scenario was created using these three steps. We found five advantages to using game engines: easier development, shorter development time, higher graphical quality, more stable simulation, and better real-time interaction, in comparison with the traditional methods. In the future, the construction industry should take advantage of the sophistication of game engines to develop more physics-based models and create a standard library. This will enhance virtual construction to the level of physics-based simulation.

The right-side wireframe view, bottom wireframe view and 3D shaded views of the forklift model.

Using Game Engine for Physics-Based Simulation - a Forklift The visualization of the collision boundaries with the convex hull polytope type.

A screenshot of the Game Logic panel: (a) the Sensors sub-panel, (b) the Controllers sub-panel, and (c) the Actuators sub-panel.

(a)

(b)

(c)

The rendering result: the process of implementing a forklift task.

(a) the view from the global camera during the task, and (b) the view from the forklift local camera during the task.

(a)

(b)

Shih-Chung Jessy Kang sckang@ntu.edu.tw sckang.caece.net