What is the best way to render 3D without a library?
Let's say I want to create a 3D environment from scratch, without any sort of library. My instinct is to create a 3D matrix (a vector, since I'm using AS3) and then manipulate objects' and cameras' positions in the matrix. Then I would calculate the position of the active camera and how much of the matrix it should be able to see, and render those parts of the matrix (the objects) into view.
I would, of course, have a separate matrix holding object positions for efficient access.
Is this efficient? Will the processor be able to handle these calculations in a single-threaded AS3 application? If not, what is a better method?
In Actionscript3 there are some basic 3D objects like Matrix3D, Vector3D, TriangleCulling, Utils3D, GraphicsTrianglePath. These objects are optimized but please don't expect wonders. I've looked into my own Engine and I can render a model with 700 faces with 20-30 fps.
So if you want to learn how 3D engines work under the hood go with option 1. Else go with option 2 or WebGL.