Tech

Why PlayStation Graphics Wobble, Flicker And Twitch

Published

on

Although often tossed together into a singular ‘retro game’ aesthetic, the first game consoles that focused on 3D graphics like the Nintendo 64 and Sony PlayStation featured very distinct visuals that make these different systems easy to distinguish. Yet whereas the N64 mostly suffered from a small texture buffer, the PS’s weak graphics hardware necessitated compromises that led to the highly defining jittery and wobbly PlayStation graphics.

These weaknesses of the PlayStation and their results are explored by [LorD of Nerds] in a recent video. Make sure to toggle on subtitles if you do not speak German.

It could be argued that the PlayStation didn’t have a 3D graphics chip at all, just a video chip that could blit primitives and sprites to the framebuffer. This forced PS developers to draw 3D graphics without such niceties like a Z-buffer, putting a lot of extra work on the CPU.

This problem extends also to texture mapping, by doing affine texture mapping, as it’s called on the PS. This mapping of textures is rather flawed and leads to the constant shifting of textures as the camera’s perspective is not taken into account. Although this texture mapping can be improved, the developers of the game have to add more polygons for this, which of course reduces performance. This is the main cause of the shifting and wobbling of textures.

Advertisement

Another issue on the PS was a lack of mipmapping support, which means a sequence of the same texture, each with each a different resolution. This allows for high-resolution textures to be used when the camera is close, and low-resolution textures when far away. On the PS this lack of mipmapping led to many texture pixels being rendered to the same point on the display, with camera movement leading to interesting flickering effects.

When it came to rendering to the output format, the Nintendo 64 created smooth gradients between the texture pixels (texels) to make them fit on the output resolution, whereas the PS used the much more primitive nearest neighbor interpolation that made especially edges of objects look like they both shimmered and changed shape and color.

The PS also lacked a dedicated floating point unit to handle graphics calculations, forcing a special Geometry Transformation Engine (GTE) in the CPU to handle transformation calculations, but all in integer calculations instead of with floating point values. This made e.g. fixed camera angles as in Resident Evil games very attractive for developers as movement would inevitably lead to visible artefacts.

Finally, the cartridge-based games of the N64 could load data from the mask ROMs about 100x faster than from the PS’s CDs, and with much lower latency. All of these differences would lead to entirely different games for both game consoles, with the N64 being clearly superior for 3D games, yet the PS being released long before the N64 for a competitive price along with the backing of Sony would make sure that it became a commercial success.

Advertisement

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *

Trending

Exit mobile version