Assembly: Microsoft.Xna.Framework.Graphics (in microsoft.xna.framework.graphics.dll)
A common use for Unproject is determining if the current cursor location intersects with an object in 3D world space. First, calculate two Vector3 values that differ only by their Z value. For instance, assume that the cursor location is currently (100, 100). Therefore, the first vector (located at the near clip plane) becomes (100, 100, 0) and the second (located at the far clip plane) becomes (100, 100, 1).
Call Unproject for each point, and store the result. For example,
minPointSource stores the result
of "unprojecting" (100,100,0), and
maxPointSource stores the result of "unprojecting" (100, 100,
1). Determine the direction vector by subtracting
Finally, normalize the direction vector, and create a Ray with
minPointSource and the now-normalized direction vector. You can now use this ray in a simple
intersect test case (for example, Intersects) with the model.
For more usage examples of Unproject, see the following: