/** Transforms a pixel in window coordinates to a ray in world coordinates. */
public static Ray windowToWorld(Camera camera, Viewport viewport, Point windowCoords) {
Vec2f ndc = viewport.windowToNDC(windowCoords);
Vec4f n =
camera
.getViewInverse()
.times(camera.getProjectionInverse().times(new Vec4f(ndc.x, ndc.y, -1, 1)));
n.divide(n.w);
Vec4f f =
camera
.getViewInverse()
.times(camera.getProjectionInverse().times(new Vec4f(ndc.x, ndc.y, 1, 1)));
f.divide(f.w);
return new Ray(n.xyz(), f.minus(n).xyz().normalized());
}
/** Transforms a point in world coordinates to a pixel in window coordinates. */
public static Point worldToWindow(Camera camera, Viewport viewport, Vec3f worldCoords) {
Vec4f clip = camera.getProjection().times(camera.getView().times(new Vec4f(worldCoords, 1)));
Vec2f ndc = clip.over(clip.w).xy();
return viewport.ndcToWindow(ndc);
}