Hmm, that code looks very similar to the 3d tutorial that I did to make my own "3d" engine in VB, although in my implementation I used "lines" to connect to 3d points to create a "wire frame" cube,

It worked somewhat, but I got some issue regarding the angles transforms.

The next point would be to do "painters algorithm" and rasterazation (i.e shading) infact you can use some API's to do all the screen polygon shading (with basic lighting)

anyway I've left the code on the "far back, back burner", go google it, it is possible, but the only reason I would do it is for educational reasons.

Anhar,