Peek-a-portal
Overview
Peek-a-portal is a technique of peeking a player's camera through the portal. It utilizes the fact that player's camera is always offset from the center of player's hitbox, which is used to detemine when the player should pass to the other side of a portal. Thanks to that, player can stand in a way so the camera goes through the portal, effectively leading to a situation where the player and their camera are on different sides of a portal.
Usage
Peek-a-portals allow portal placements that would otherwise be tricky or slower to achieve, thanks to the ability to shoot portals from a location of one of your portals and not the location you're currently in. This is mostly used for reportals, as falling into a floor portal gives you a perfect time window where you're still within a portal and your camera is still peeking through it, which gives you an opportunity to pre-aim a portalable surface to shoot. In addition, peeking through a portal completely avoids the effect of portal placement helpers, letting you place a portal on a placement helper in unintended manner. A huge advantage can be taken from using Quantum Crouch with peek-a-portal - as long as your hitbox intersects portal's hitbox, your camera is able to peek through a portal, which allows you to get a camera into inaccessible places.
Types of peek-a-portals
We're categorizing several types of peek-a-portals depending on their execution and the final outcome.
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