New Feature:

1. I created a collision-based Anti-Portal border for the portal.
   
   
   
   
2. New level asset: Spring Zone. The spring's elasticity can be tuned in RTE mode. Acceleration is applied along the local Z-axis, allowing for versatile player propulsion.
   
3.  I've provided several material asset balls for RTE mode! These can be used to adjust level materials.
   
4. Portal stacking is no longer allowed.
   
   
   
   
5. Players can always pass through portals smoothly, no matter how fast they're moving.