I'm looking for an algorithm where I can unfold a 3d shape into it's net and make the necessary cuts, this is to visualise something that is to be constructed out of a flat material.
Imagine folding sheet metal into a dustpan or something. I guess I'm more after the code or the maths for it than a program that does it.
Maybe even knowing the name of what this sort of process is called would help me look it up?

You could use this, it's designed for papercraft models:
http://www.tamasoft.co.jp/pepakura-en/

OP wanted the algorithms rather than software that does it.

It's an interesting computational problem. Someone posted a question on Stack Overflow and the answers have some links to papers and open source software that does it:
http://stackoverflow.com/questions/963084/decomposing-a-3d-mesh-into-a-2d-net

Whoa, don't jump down his throat. It was a fast response with a possible solution.
I say, good work Mantorok.

he didn't, he just replied civilly

Whoah, no need to jump down Lynx's throat about Dazhel jumping down Mantoroks throat.

who asked you shad

wow this stuff is very complicated
I'm looking into another option, I found this program http://www.javaview.de/services/unfold/index.html and apparently there is a way to make applets that use this program which may suit my purposes? No idea yet.

Whoa, everyone's a little touchy!

Mostly ninjas in this thread suffering through Talk Like a Pirate day perhaps?
Yeeaarrr!

Your mum likes it when I jump down her throat.

What exactly are you trying to do thermite? Because you just want the algorithm I take it you're trying to write your own program? Is this for UNI or something?

hey f*** you dazhel, shad wasn't being touchy

Im learning F#, this could be a good little project. How many different types of 3d objects are you trying to support?

Nah it's not for uni, I've been doing some thinking and I want to make a program with a web interface where you can unfold shapes, however I want to take it a step further and account for the flexibility and thickness of the building material which I already have some ideas for, and maybe let you 'edit' the shape a bit - so the resulting 2d nets would have to be dynamically calculated. It's just an idea and doing it from scratch does seem like a lot of effort, so I was hoping to take bits of code from other open source projects like 3d editors. That link I gave above is exactly the type of thing I want to make - and apparently it is an applet made with some java program as an api or something like that so I reckon that might be the go - as long as I can change what it does enough.