// Builds a tessellated grid of quads across the provided bounds with three sets of UVs used to account for
// lens distortion and chromatic aberration.
public static Mesh CreateDistortMesh(SteamVR.IHmd hmd, SteamVR.Hmd_Eye eye, int resU, int resV, Rect bounds)
{
int numVerts = resU * resV;
var vertices = new Vector3[numVerts];
var redUVs = new Vector3[numVerts];
var greenUVs = new Vector2[numVerts];
var blueUVs = new Vector2[numVerts];
int iTri = 0;
int resUm1 = resU - 1;
int resVm1 = resV - 1;
var triangles = new int[2 * 3 * resUm1 * resVm1];
for (int iV = 0; iV < resV; iV++)
{
float v = (float)iV / resVm1;
float y = SteamVR_Utils.Lerp(bounds.yMax, bounds.yMin, v); // ComputeDistortion expects 0,0 in upper left
for (int iU = 0; iU < resU; iU++)
{
float u = (float)iU / resUm1;
float x = SteamVR_Utils.Lerp(bounds.xMin, bounds.xMax, u);
var coords = hmd.ComputeDistortion(eye, u, v);
int idx = iV * resU + iU;
vertices[idx] = new Vector3(x, y, 0.1f);
redUVs[idx] = new Vector3(coords.rfRed[0], 1.0f - coords.rfRed[1], 0);
greenUVs[idx] = new Vector2(coords.rfGreen[0], 1.0f - coords.rfGreen[1]);
blueUVs[idx] = new Vector2(coords.rfBlue[0], 1.0f - coords.rfBlue[1]);
if (iV > 0 && iU > 0)
{
int a = (iV - 1) * resU + (iU - 1);
int b = (iV - 1) * resU + iU;
int c = iV * resU + (iU - 1);
int d = iV * resU + iU;
triangles[iTri++] = a;
triangles[iTri++] = b;
triangles[iTri++] = d;
triangles[iTri++] = a;
triangles[iTri++] = d;
triangles[iTri++] = c;
}
}
}
var mesh = new Mesh();
mesh.vertices = vertices;
mesh.normals = redUVs; // stuff data in normals since only two uv sets exposed
mesh.uv = greenUVs;
mesh.uv2 = blueUVs;
mesh.triangles = triangles;
return(mesh);
}
public void Init(SteamVR_Camera tracker, SteamVR.Hmd_Eye eye, float depth)
{
this.tracker = tracker;
this.eye = eye;
var hmd = SteamVR.IHmd.instance;
var i = (int)eye;
uint x = 0, y = 0, w = 0, h = 0;
hmd.GetEyeOutputViewport(eye, ref x, ref y, ref w, ref h);
overlaySettings.kernel = new Vector3[] { // AA sub-pixel sampling (2x2 RGSS)
new Vector3(0.125f / w, -0.375f / h, 0),
new Vector3(0.375f / w, 0.125f / h, 0),
new Vector3(-0.125f / w, 0.375f / h, 0),
new Vector3(-0.375f / w, -0.125f / h, 0)
};
float left = 0.0f, right = 0.0f, top = 0.0f, bottom = 0.0f;
hmd.GetProjectionRaw(eye, ref left, ref right, ref top, ref bottom);
var camera = GetComponent <Camera>();
float zFar = camera.farClipPlane;
float zNear = camera.nearClipPlane;
var m = Matrix4x4.identity;
float idx = 1.0f / (right - left);
float idy = 1.0f / (bottom - top);
float idz = 1.0f / (zFar - zNear);
float sx = right + left;
float sy = bottom + top;
m[0, 0] = 2 * idx; m[0, 1] = 0; m[0, 2] = sx * idx; m[0, 3] = 0;
m[1, 0] = 0; m[1, 1] = 2 * idy; m[1, 2] = sy * idy; m[1, 3] = 0;
m[2, 0] = 0; m[2, 1] = 0; m[2, 2] = -zFar * idz; m[2, 3] = -zFar * zNear * idz;
m[3, 0] = 0; m[3, 1] = 0; m[3, 2] = -1.0f; m[3, 3] = 0;
camera.projectionMatrix = m;
camera.depth = depth; // enforce rendering order
camera.eventMask = 0; // disable mouse events
camera.orthographic = false; // force perspective
camera.aspect = (float)w / h;
// Use fov of projection matrix (which is grown to account for non-linear undistort)
camera.fieldOfView = (Mathf.Atan(bottom) - Mathf.Atan(top)) * Mathf.Rad2Deg;
// Copy and clear clearFlags to avoid duplicate work.
if ((int)clearFlags == 0)
{
clearFlags = camera.clearFlags;
camera.clearFlags = CameraClearFlags.Nothing;
}
camera.targetTexture = SteamVR_Camera.sceneTexture;
overlaySettings.invProj = m.inverse;
transform.parent = tracker.offset;
transform.localScale = Vector3.one;
var t = new SteamVR_Utils.RigidTransform(hmd.GetHeadFromEyePose(eye));
transform.localPosition = t.pos;
transform.localRotation = t.rot;
if (distortMesh[i] == null)
{
var viewportWidth = SteamVR_Camera.viewportTexture.width;
var viewportHeight = SteamVR_Camera.viewportTexture.height;
var eyeViewport = new Rect(
2.0f * x / viewportWidth - 1.0f,
2.0f * y / viewportHeight - 1.0f,
2.0f * w / viewportWidth,
2.0f * h / viewportHeight);
distortMesh[i] = SteamVR_Utils.CreateDistortMesh(hmd, eye, 32, 32, eyeViewport);
}
}
