public static Vector2 Project(this IRenderMatrices renderMatrices, Vector3 point)
{
renderMatrices.Update();
var matrix = renderMatrices.ScreenViewProjectionMatrix;
var pointTransformed = Vector3.TransformCoordinate(point, matrix);
var pt = new Vector2(pointTransformed.X, pointTransformed.Y) / renderMatrices.DpiScale;
return(pt);
}
/// <summary>
/// Un-project 2D screen point onto 3D space by camera.
/// </summary>
/// <param name="renderMatrices">The renderMatrices.</param>
/// <param name="point2d">The point2d.</param>
/// <param name="ray">The ray.</param>
/// <returns></returns>
public static bool UnProject(this IRenderMatrices renderMatrices, Vector2 point2d, out Ray ray)//, out Vector3 pointNear, out Vector3 pointFar)
{
if (renderMatrices == null)
{
ray = new Ray();
return(false);
}
renderMatrices.Update();
var px = point2d.X;
var py = point2d.Y;
var viewInv = renderMatrices.ViewMatrixInv;
var projMatrix = renderMatrices.ProjectionMatrix;
var w = renderMatrices.ActualWidth / renderMatrices.DpiScale;
var h = renderMatrices.ActualHeight / renderMatrices.DpiScale;
var v = new Vector3
{
X = (2 * px / w - 1) / projMatrix.M11,
Y = -(2 * py / h - 1) / projMatrix.M22,
Z = 1 / projMatrix.M33
};
Vector3.TransformCoordinate(ref v, ref viewInv, out var zf);
Vector3 zn;
if (renderMatrices.IsPerspective)
{
zn = viewInv.Row4.ToVector3();
}
else
{
v.Z = 0;
Vector3.TransformCoordinate(ref v, ref viewInv, out zn);
}
var r = zf - zn;
r.Normalize();
ray = new Ray(zn + r * renderMatrices.CameraParams.ZNear, r);
return(true);
}
