Interactive and Immersive Visualization of Fluid Dynamics using Virtual Reality

Summary

The article describes a method to visualize three-dimensional fluid flow data in virtual reality. The detailed protocol and shared data and scripts do this for a sample data set from water tunnel experiments, but it could be used for computational simulation results or 3D data from other fields as well.

Abstract

The last decade has seen a rise in both the technological capacity for data generation and the consumer availability of immersive visualization equipment, like Virtual Reality (VR). This paper outlines a method for visualizing the simulated behavior of fluids within an immersive and interactive virtual environment using an HTC Vive. This method integrates complex three-dimensional data sets as digital models within the video game engine, Unity, and allows for user interaction with these data sets using a VR headset and controllers. Custom scripts and a unique workflow have been developed to facilitate the export of processed data from Matlab and the programming of the controllers. The authors discuss the limitations of this particular protocol in its current manifestation, but also the potential for extending the process from this example to study other kinds of 3D data not limited to fluid dynamics, or for using different VR headsets or hardware.

Introduction

Virtual reality (VR) is a tool that has seen increasing levels of popularity as it provides a new platform for collaboration, education, and research. According to Zhang et al., “VR is an immersive, interactive computer-simulated environment in which the users can interact with the virtual representations of the real world through various input/output devices and sensory channels¹.” Fluid dynamics is a field of physics and engineering that attempts to describe the motion of liquids or gases due to pressure gradients or applied forces. Because the study of fluid dynamics is driven by the analysis of large data sets, a significant par....

Protocol

1. Processing data files and exporting objects from Matlab

NOTE: The following steps will detail how to open the shared Matlab processing codes, which open PLOT3D data files and generate the isosurfaces as described. The necessary .obj and .mtl files are then also constructed and exported from Matlab.

1. From the supplementary files, download the scripts labeled create_obj.m and write_wobj.m. Open Matlab, then open the create_obj.m and the write_wobj.m files.
2. Customize the path FileDir to the folder where scripts and data files are saved.....

Results

Using the method described above, the results are created from the example dataset, which was split into 24 time steps and saved in the PLOT3D standard data format. Since 3 quantities were saved, 72 .obj files were created in Matlab and converted into 72 .fbx files in Blender and imported into Unity. The Matlab code can be adjusted according to the number of time steps of the user’s data by changing the number of times that Matlab iterates through the main for loop, which can be found at the very beginning of the s.......

Discussion

In this article, we described a method for representing fluid dynamics data in VR. This method is designed to start with data in the format of a PLOT3D structured grid, and therefore can be used to represent analytic, computational, or experimental data. The protocol describes the necessary steps to implement the current method, which creates a VR “scene” that allows the user to move and scale the data objects with the use of hand movements, to cycle through time steps and quantities, and to create drawings a.......

Materials

Name	Company	Catalog Number	Comments
Base station	HTC and Valve Corporation		Used to track the user's position in the play area.
Base station	HTC and Valve Corporation		Used to track the user's position in the play area.
Link box	HTC and Valve Corporation		Used to connect the headset with the computer being used.
Vive controller	HTC and Valve Corporation		One of the controllers that can be used.
Vive controller	HTC and Valve Corporation		One of the controllers that can be used.
Vive headset	HTC and Valve Corporation		Headset the user wears.