This is a 3D engine for the Sega Dreamcast, it is based on DC Land. I wrote this using all my own code for both 2D drawing functions (from DC Land) and 3D engine code, it uses no hardware geometry functions.
The wireframe object displayed is created from a 2D profile that you input first using the control pad. A volume sweep is used to transform the profile into a 3D object.
Using the control pad you can translate, rotate and scale the object. You can also change the perspective and there is an option to show the object as depth sorted filled polygons instead of a wireframe, making it look solid.