fix up/downward thrusters

src/camera.rs

@@ -140,8 +140,9 @@ fn run_camera_controller(
             engine.thrust_back
         });
         let right = *transform.right() * engine.thrust_sideways * engine.current_warmup;
+        let up = *transform.up() * engine.thrust_sideways * engine.current_warmup;
         actor.v += controller.velocity.x * dt * right
-            + controller.velocity.y * dt * Vec3::Y
+            + controller.velocity.y * dt * up
             + controller.velocity.z * dt * forward;
 
         controller.velocity = Vec3::ZERO;