I often think about making something with vulkan.
I always wanted to make my own mini 3D editor and code it from scratch.
And integrate a external renderer to it. That you can make meshes in and export to different file formats or render a image from it with PBRT or something like that.
Or - integrate pbrt ( https://github.com/mmp/pbrt-v4 ) in https://www.gafferhq.org/
I'm a bit torn, and cannot decide or find proper motivation.