Ghost Portal System

Ghost Portal turns a pair of linked surfaces into a real window between two places. Look into one portal and you see out of the other, rendered live and sampled in screen space, so the illusion holds from any angle and on any mesh shape.

It does everything players expect from a portal, out of the box:

Look through. A hidden camera renders the exit portal's view into a texture and samples it on the portal surface. Oblique near-plane clipping keeps geometry from poking through, and the view lines up pixel-for-pixel with the player's eye no matter where they stand.

Shoot through — with zero setup. A portal-aware raycast redirects shots out of the linked portal so they land on the correct target on the far side. Drop it into your weapon script in place of Physics.Raycast and it just works: portals are detected analytically, so they need no solid collider, no dedicated physics layer and no collision-matrix work. One shot can pass through as many portals as you allow.

Walk & fly through. Rigidbodies that cross the portal plane are teleported to the linked portal with transformed position, rotation and velocity — they come out the other side and keep moving. A swept-crossing projectile component keeps even the fastest bullets from tunnelling, no matter their speed.

Infinite recursion. Point two portals at each other and the view is drawn inside itself, for the classic infinite-corridor look. The depth is yours to choose, levels that could never be seen are skipped automatically, and deeper levels render at reduced resolution — so the effect costs far less than the depth setting suggests. Toggle it at runtime as a quality setting.

Any shape you like. Because the view is sampled in screen space, the portal surface can be any mesh — a rectangle, a round disc, a torus frame, or your own model. Round and quad portal meshes are included.

Built for performance. Portals that are off-screen, out of range or hidden behind a wall are skipped automatically. Shadows and post-processing are turned off on the portal camera, render resolution is adjustable, and per-portal layer masks keep the extra render lean.

Designer-friendly. UnityEvents fire when a traveller enters, and when a portal comes into or leaves view — perfect for sounds, animations and effects. An optional scaling module opens a portal pair when the player looks at it and closes it again a few seconds later, with its own open/close events, or holds them permanently open with a single checkbox.

What's included

• Core portal system plus a swept projectile traveller and an optional open/close scaling module.
• Ready-made portal prefabs (quad, circle) and a pre-linked portal pair you can drop straight into a scene.
• Round and torus portal meshes, portal material and URP shader.
• A playable demo scene with a first-person controller and a demo weapon offering two fire modes — flying projectile or instant hitscan — with an impact system and a built-in crosshair.
• Clean, commented C# source and a 12-page illustrated PDF manual.

Requirements

• Unity 6.0 LTS or newer
• Universal Render Pipeline (URP)
• Input System package (demo scene only)

Not included

• The environment art and props from the showcase video.

Questions, bug reports and feature requests: https://discord.gg/zzse5yGm4v