See the source here.
I've been writing a lightweight 3D rendering engine using SDL3_GPU to learn about modern graphics APIs, as prior to this I've mostly only used OpenGL.
SDL3_GPU is a cross-platform graphics and compute that acts as a wrapper around platforms like Vulkan and Metal and integrates with SDL3. By necessity it is not quite as low-level as raw Vulkan, as it must abstract over different backends, but generally has the same modern graphics API style and most of the flexibility of working with those libraries directly.
Currently, the experimentation is not particularly focused. It contains both a hex grid renderer, along with the accompanying hex mathematics support, and also a version of my light-weight ECS. Depending on the direction I take the prototype, I'll probably only need one of these two systems, but moving a bunch of models around with the ECS will provide a decent stress test for the real-time rendering capabilities.
The project can load GLB model files, which is what I use to get the little tree models. Currently it doesn't support the entire GLB featureset, but that is mostly fine, as I won't have any need for things like multi-scene models (and if I did, I'd probably just use a library).
The demo built in to the project shows a fairly simple procedural generation algorithm applied to the hexagonal grid to produce some interesting terrain to render.