Not to long ago i started to create a small 3D engine in javascript to combine this with an html5 canvas.

One of the issues I run into is how can you transform 3d to 2d coords. Since I cannot use matrices or built in transformation methods I need another way.

I've tried implementing the next explanation + pseudo code: http://freespace.virgin.net/hugo.elias/routines/3d_to_2d.htm

Unfortunately no luck there. I've replace all the input variables with data from my own camera and object classes.

I have the following data: An object with a rotation, position vector and an array of 4 3d coords (its just a plane) a camera with a position and rotation vector the viewport -> a square 600 x 600 surface. The example uses a zoom factor which I've set as 1

Most hits on google use either matrix calculations or don't implement camera rotation. Basic transformation should be like this: screen.x = x / z * zoom screen.y = y / z * zoom

Can anyone point me in the right direction or explain to me howto achieve this?

edit: Thanks for all your posts, I haven't been able to apply all this to my project yet but I hope to do this soon.