How do "Mode 7" 3D-like graphics work? Well, it's all a clever trick using affine transformations that update each scanline to render one slice of the background at a time, creating the illusion of a projective plane in 3D space.
On the left is what the rendered output looks like when the last matrix parameters are left intact, updating each scanline. On the right is what the ACTUAL Mode7 affine transformation looks like during that scanline!
Pretty neat stuff! The SNES cant generate projective transformations without special hardware, so this is how the Psuedo-3D projective plane is generated for #SuperMarioKart
What's interesting about this is that Mode7 isn't actually what's responsible for the projective effect, HDMA is! You could technically do a *similar* effect with other BG modes, and actually Yoshi's Island uses a similar technique for its "3D" objects as well (that's also a super cool method I want to talk about later)
@MrL314 everybody knows and talks about Mode 7 (and the SuperFX chip) but there really isn't enough talk about HDMA, which the SNES uses for SO MANY TRICKS LIKE THIS
it's the secret to everything from gradient textboxes in RPGs to the stencil effects used in Super Mario World (the expanding/contracting keyholes) and Super Metroid (the X-Ray Scope)
anything that wobbles or wiggles is using an HDMA effect as well
@theryusui HDMA truly is the powerhouse of the SNES! Also any major windowing effects that are not specifically vertical are HDMA powered, like the menu box for the title screen of SMK, and pretty much everything you require swapping background modes either requires IRQ or HDMA to work, but HDMA is just *so* much cleaner to work with
@theryusui @MrL314 There are also gameboy games that change colours between scanlines for high-colour art. Infinity used it for text box gradients, and Cannon Fodder used it for full colour video.
@MrL314 for those curious just what the heck HDMA is, it's "horizontal-blank direct memory access," it's a hardware feature that lets games tweak graphics settings PER SCANLINE
like it's funny to think that the Atari 2600 was technically capable of tricks like this (by virtue of being ONLY able to display graphics one scanline at a time) and it wasn't until the SNES that we had another home console that could pull them off (AFAIK)