VR-Head-Motion-Simulator

Description

This repository contains a C# script designed to simulate head motion within a Unity VR environment. The script utilizes head data, including timeframe, positional coordinates (x, y, z), and orientation parameters (qx, qy, qz, qw), all of which are sourced from a CSV file.

Requirements

Unity Editor version 2022.3.19f1. If you want to download the repository and run it in your Unity, you should adjust your Unity editor version to 2022.3.19f1. Alternatively, you can use the instructions and C# code with your own Unity editor version.

Setup

1. Clone the repository.
2. Open the project in Unity Editor.
3. Replace the csvFilePath in the HeadMotionSimulator.cs script in the Assets with the path of your head_motion.csv file.

Usage

The script should be attached to a GameObject named VRHeadset in the Unity hierarchy. If you want to use the code with your own Unity editor version, follow these steps:

1. Create a GameObject and name it VRHeadset.
2. Attach the HeadMotionSimulator.cs script to the VRHeadset GameObject.
3. Right-click on the VRHeadset GameObject in the hierarchy and create a Camera object.
4. In the Inspector of the camera, add Tracked Pose Drive and adjust the following options:
   • Device: Generic XR Device
   • Pose Source: Center Eye
   • Tracking Type: Rotation and Position
   • Update Type: Update and Before Render

C# Code

The HeadMotionSimulator.cs script reads the head_motion.csv file, which includes time and x, y, z positions and qx, qy, qz, qw orientations. The script then simulates the head motion in the VR environment based on this data.

using UnityEngine;
using System.Collections;
using System.IO;
using System.Collections.Generic;

public class HeadMotionSimulator : MonoBehaviour
{
    public string csvFilePath = "your_head_motion.csv_path";
    private List<HeadMotionData> motionData;
    private int currentIndex = 0;
    private float timeBetweenRows = 0.001f; // 1 millisecond

    void Start()
    {
        // Read and parse the .csv file
        motionData = ReadCSVFile(csvFilePath);
        Time.timeScale = 1; // Set the time scale to 1 for one millisecond runtime between rows
    }

    void Update()
    {
        if (motionData != null && motionData.Count > 0)
        {
            // Update cube position and rotation based on the motion data
            transform.position = new Vector3(motionData[currentIndex].x, motionData[currentIndex].y, motionData[currentIndex].z);
            transform.rotation = new Quaternion(motionData[currentIndex].qx, motionData[currentIndex].qy, motionData[currentIndex].qz, motionData[currentIndex].qw);

            // Update currentIndex for the next frame
            currentIndex++;

            // Check if this is the last row
            if (currentIndex >= motionData.Count)
            {
                // Stop the program
                Application.Quit();
            }

            // Wait for 1 milisecond before processing the next row
            StartCoroutine(WaitForNextRow());
        }
    }

    private IEnumerator WaitForNextRow()
    {
        yield return new WaitForSeconds(timeBetweenRows);
    }

    private List<HeadMotionData> ReadCSVFile(string filePath)
    {
        List<HeadMotionData> data = new List<HeadMotionData>();
        if (File.Exists(filePath))
        {
            // Read the lines of the .csv file
            string[] lines = File.ReadAllLines(filePath);
            for (int i = 1; i < lines.Length; i++) // Start from 1 to skip the header
            {
                string[] values = lines[i].Split(',');
                if (values.Length >= 8) // Ensure all columns are present
                {
                    HeadMotionData motion = new HeadMotionData();
                    // Parse and assign the values to the HeadMotionData object
                    motion.time = float.Parse(values[0]);
                    motion.x = float.Parse(values[1]);
                    motion.y = float.Parse(values[2]);
                    motion.z = float.Parse(values[3]);
                    motion.qx = float.Parse(values[4]);
                    motion.qy = float.Parse(values[5]);
                    motion.qz = float.Parse(values[6]);
                    motion.qw = float.Parse(values[7]);
                    data.Add(motion);
                }
                else
                {
                    Debug.LogError("Invalid data in the .csv file at line " + (i + 1));
                }
            }
        }
        else
        {
            Debug.LogError("File not found: " + filePath);
        }
        return data;
    }
}

public class HeadMotionData
{
    public float time;
    public float x;
    public float y;
    public float z;
    public float qx;
    public float qy;
    public float qz;
    public float qw;
}

Note: Remember to replace the your_head_motion.csv_path with the path of your head_motion.csv file.

Author

Mohammad Elahi, TU Dresden, Vodafone Chair, [email protected]