GTA San Andreas creator explains why reflections stepped out of mirrors. Creepy consequences of technical tricks

Grand Theft Auto San Andreas pleasantly surprised players with its attention to detail, but issues arose in some areas. Bypassing technical limitations sometimes led to rather creepy scenes

Grand Theft Auto San Andreas is remarkably detailed, just like many other Rockstar projects. However, when encountering mirrors, some players noticed strange (or even creepy) things.

The issue was that reflections looked as if they were about to step out of the mirror and into the real world. Obbe Vermeij, former technical director at Rockstar North, explained how this happened.

It turns out it was all due to technical limitations. While developing GTA San Andreas, tricks had to be used because of a lack of memory (it was impossible to create “normal” reflections, and Rockstar was forced to improvise):

“We didn’t have the video memory to draw mirrors properly. Instead, I rendered a mirrored version of the scene at the same time as the scene itself.

This method has a few problems:

- Mirrors can only be on an outside wall of a room.

- Characters and objects can step out of the mirror (horror movie style).

- Back-face culling is now incorrect, so some models show their back faces as a result. (Like the shelf in the screenshot).

Not ideal, but better than mirrorless barber shops.

The usual way to render mirrors is to render the scene twice. The first time — from the perspective of the mirror camera. The resulting image is used as the mirror texture when rendering the actual scene.

This method requires video memory to store the first render. We simply didn’t have that free video memory in SA”.

Thus, a technical limitation led to the use of tricks that spawned eerie mirror scenes in Grand Theft Auto San Andreas.

The equipment in the reflection of the shelf (on the left) is displayed from the reverse side.

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