SteamVR_TestTrackedCamera.cs

//======= Copyright (c) Valve Corporation, All rights reserved. ===============
using UnityEngine;

public class SteamVR_TestTrackedCamera : MonoBehaviour
{
    public Material material;
    public Transform target;
    public bool undistorted = true;
    public bool cropped = true;

    void OnEnable()
    {
        // The video stream must be symmetrically acquired and released in
        // order to properly disable the stream once there are no consumers.
        var source = SteamVR_TrackedCamera.Source(undistorted);
        source.Acquire();

        // Auto-disable if no camera is present.
        if (!source.hasCamera)
            enabled = false;
    }

    void OnDisable()
    {
        // Clear the texture when no longer active.
        material.mainTexture = null;

        // The video stream must be symmetrically acquired and released in
        // order to properly disable the stream once there are no consumers.
        var source = SteamVR_TrackedCamera.Source(undistorted);
        source.Release();
    }

    void Update()
    {
        var source = SteamVR_TrackedCamera.Source(undistorted);
        var texture = source.texture;
        if (texture == null)
        {
            return;
        }

        // Apply the latest texture to the material.  This must be performed
        // every frame since the underlying texture is actually part of a ring
        // buffer which is updated in lock-step with its associated pose.
        // (You actually really only need to call any of the accessors which
        // internally call Update on the SteamVR_TrackedCamera.VideoStreamTexture).
        material.mainTexture = texture;

        // Adjust the height of the quad based on the aspect to keep the texels square.
        var aspect = (float)texture.width / texture.height;

        // The undistorted video feed has 'bad' areas near the edges where the original
        // square texture feed is stretched to undo the fisheye from the lens.
        // Therefore, you'll want to crop it to the specified frameBounds to remove this.
        if (cropped)
        {
            var bounds = source.frameBounds;
            material.mainTextureOffset = new Vector2(bounds.uMin, bounds.vMin);

            var du = bounds.uMax - bounds.uMin;
            var dv = bounds.vMax - bounds.vMin;
            material.mainTextureScale = new Vector2(du, dv);

            aspect *= Mathf.Abs(du / dv);
        }
        else
        {
            material.mainTextureOffset = Vector2.zero;
            material.mainTextureScale = new Vector2(1, -1);
        }

        target.localScale = new Vector3(1, 1.0f / aspect, 1);

        // Apply the pose that this frame was recorded at.
        if (source.hasTracking)
        {
            var t = source.transform;
            target.localPosition = t.pos;
            target.localRotation = t.rot;
        }
    }
}