Super Mario 64 for the PS1

> Tessellation (up to 2x) to reduce issues with large polygons

From the videos I've watched there is still insane amounts of affine transformation texture warping, is that because it's not enable or because 2x is not enough?

I guess they will need to also redo all level geometry to be more amenable to tesselation... I guess that's why many ps1 games had blocky looking levels.

I see a lot of texture warp like you mentioned but I'm not seeing the geometry popping (wobble?) that was a hallmark of ps1 games, I'm guessing they're using soft floating point for the geometry and doing perspective-correct texture mapping would just be too expensive for decent frame rate

The PS1's GPU does not support perspective correction at all; it doesn't even receive homogeneous 3D vertex coordinates, instead operating entirely in 2D screen space and leaving both 3D transformations and Z-sorting to the CPU [1]. While it is possible to perform perspective correct rendering in software, doing so in practice is extremely slow and the few games that pull it off are only able to do so by optimizing for a special case (see for instance the PS1 version of Doom rendering perspective correct walls by abusing polygons as "textured lines" [2]).

[1]: https://github.com/spicyjpeg/ps1-bare-metal/blob/main/src/08... - bit of a shameless plug, but notice how the Z coordinates are never sent to the GPU in this example.

[2]: https://fabiensanglard.net/doom_psx/index.html

It's funny that the PS1 got so famous for 3d games, when its 'GPU' was entirely 2d.

I guess the main thing the console brought to the table that made 3d (more) feasible was that the CPU had a multiplication instruction?