All posts in portals

In Portal, you can see portals in portals, which requires recursively mapping the view from one portal in another portal.

Firing portals and snapping them to the edge of a wall without overhangs involves a lot of fiddly raycasts. Plus, let's shoot portals through portals, Narbacular Drop-style.

When an object travels through one portal, its momentum must be conserved. Plus, we need to render a clone whenever the object is partway through a portal.

Using an oblique projection matrix to set up a view frustum is crucial for properly culling objects behind the portal plane without culling anything in front of it.

Rendering the view from behind one portal on the surface of its paired portal requires a bunch of space transformations and stencils.

Spyro renders the skybox of an upcoming level inside the portal for that level, then swaps the active skybox as you cross its threshold.

In this series of articles, we'll discuss portal rendering techniques for Spyro the Dragon and Portal.