It’s still possible EAD Tokyo didn’t put much stock in the technique though, or that their workflow was not set up for that at this point, or that hardware limitations otherwise made rendering coins using normal mapping worse than fully modelling them.
The bumpmapping hardware most wikis mention as "supporting normal mapping" is pretty much irrelevant.
The G400 was generally lackluster at 3d performance, so the feature didn't really get used by games.
https://www.nintendoworldreport.com/guide/1786/gamecube-faq-...
Quite often it’s not even a question of the GPU itself but the development pipeline and the tooling used. As well as ofc does the engine itself supports it.
Also at the end of the day your GPU has finite amount of compute resources many of them are shared across various stages of the rendering pipeline even back at the 6th and 7th gen of consoles where fixed function units were far more common.
In fact in many cases even back then if you used more traditional “fixed function pipelines” the driver would still convert things into shaders e.g. hardware T&L even on the Wii was probably done by a vertex shader.
Many teams especially in companies that focus far more on gameplay than visuals opted out for simpler pipelines that have fewer variables to manage.
It’s much easier to manage the frame budget if you only need to care about how many polygons and textures you use, as if the performance is too low you can reduce the complexity of models or number/size of textures.
Shaders and more advanced techniques require far more fine grain optimization especially once you get into deferred or multi pass rendering.
So this isn’t hardware, it’s that the team behind it either didn’t want or didn’t need to leverage the use of normal mapping to achieve their design goals.
Nope, no vertex shaders on the Wii, just a hardware T&L unit with no code upload feature.
Some exec from Nintendo is on record as saying something along the lines that texture mapping looks bad and should be avoided. My conspiracy theory is that it was a conscious decision at Nintendo to limit the ability of its consoles to do stuff with textures. The N64 was even worse, a lot worse: it only had 4kB of texture cache.