How does ToScreen() work?

[Ollie]

I'm interested in knowing how ToScreen calculates the 2d position from 3d position.
I hope someone could explain this to me as detailed as possible.
I'm pretty sure it would need your camera position , your viewangle and the 3d position.

TL;DR How can i recreate the ToScreen function with pseudocode/lua?

[Darkwater]

[url]http://facepunch.com/showthread.php?t=891702&p=32941555&viewfull=1#post32941555[/url]

[ash47]

I learnt how to do this in Linear Algebra :D It uses Vector Projections, from the looks of things, the post above mine has covered it very well :P