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PlayStation u/basement_arcade ·

Why do textures and 3D models wobble or warp in PlayStation 1 games?

I've been playing some original Tomb Raider and Silent Hill on my PS1, and I noticed that the walls and character models look like they are vibrating or warping whenever the camera moves. It makes the textures look like they are sliding around. What causes this weird visual glitch on the hardware?

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3 comments

  • u/onemorelife ·
    Developers had to use creative programming tricks to minimize these hardware limitations on the original PlayStation. To reduce texture warping, they would subdivide large polygons into smaller ones so the affine mapping errors were less noticeable, or design environments with fixed camera angles that minimized oblique views.
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  • u/joystickjen ·
    The PlayStation 1 GPU lacks support for subpixel precision, which is the main cause of the wobbling effect. When the system calculates the vertices of 3D models, it rounds their coordinates to the nearest whole pixel on the screen. As the camera moves, these coordinates snap abruptly from one pixel to the next, causing the polygons to jitter.
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  • u/thirtylives ·
    Another major factor is that the PlayStation 1 GPU does not perform perspective-correct texture mapping. It uses a simpler method called affine texture mapping, which projects textures in 2D space without accounting for the depth or distance of the polygon from the camera. This makes textures warp and distort when viewed from sharp angles.
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