protected static void viewProjFromLightAlignedBB(ref SSAABB bb,
ref Matrix4 lightTransform,
ref Vector3 lightY,
out Matrix4 viewMatrix,
out Matrix4 projMatrix)
{
// Use center of AABB in regular coordinates to get the view matrix
Vector3 targetLightSpace = bb.Center();
Vector3 eyeLightSpace = new Vector3(targetLightSpace.X,
targetLightSpace.Y,
bb.Min.Z);
Vector3 viewTarget = Vector3.Transform(targetLightSpace, lightTransform.Inverted());
Vector3 viewEye = Vector3.Transform(eyeLightSpace, lightTransform.Inverted());
Vector3 viewUp = lightY;
viewMatrix = Matrix4.LookAt(viewEye, viewTarget, viewUp);
// Finish the projection matrix
Vector3 diff = bb.Diff();
float width, height, nearZ, farZ;
width = diff.X;
height = diff.Y;
nearZ = 1f;
farZ = 1f + diff.Z;
projMatrix = Matrix4.CreateOrthographic(width, height, nearZ, farZ);
}
