Sprite to Voxel is a package that aims to make 3D game development more accessible to developers that don’t have a great deal of experience in 3D modelling, whilst also tucking away the model rendering code into easy-to-use scripts.
Sprite to Voxel allows the developer to build 3D models out of 2D sprites, by stacking them on top of each other and converting each pixel into a voxel (a 3D 1x1x1 cube).
The package comes as a test project (though to use in your games you only need the "SpriteToVoxel" folder of scripts). The test project shows how you can use these scripts to convert your sprites into models.
You can view the ".exe" output of this test project here, if you want to see what Sprite to Voxel can do!
Full documentation can be found here, and should be the first point of reference if you run into any problems, as I've tried to be quite comprehensive! As well as a "Basic Use" section, there are notes on best practices to optimise your game's performance with this package.