How to do Flight AI and Pathfinding in ungrounded space?

When doing space games, or flight games in general how do you handle AI and pathfinding for the NPC’s? For example dogfighting and having the AI avoid obstacles, going around things with no navmesh floor to compute a traditional path on?

For starters, I’ve started by trying to do the whole AI with a physics motor (more responsive to impacts/damage etc…) and use a target point for movement that it simply tries to reach, so I should be able to just move that target point based on background algorithms that find obstacles, calculate priorities and such. I’ve got the motor working alright, it will follow the target but the difficult part is getting it to avoid obstacles intelligently without a navmesh. The target may be on the other side of some huge asteroids or something.

Can I use a dynamic navmesh that is parented to the player? How would I get it to utilize all axi in path building?

Anyway I’m mostly wanting to get a functional system for avoiding objects in all directions to reach a final target. Is this a good approach? What else could I do?

I guess to simplify:

I need local avoidance and target placement for an aircraft in 3d space… Not sure how to approach the design. Locomotion is working fine currently, it just needs a target.

Progress on this:

http://dl.dropboxusercontent.com/u/38606641/AI/AI-test/AI-test.html

.unitypackage Download Link for AI Test r2

You’ll see Pink explosions and maybe some other materials and stuff since some of the FX are paid assets pieces.

The Asteroids I made are also included. The spaceship is a free asset redist from the Asset Store.

I was just reading a tutorial series on steering behavior today. This may be of some help of you if you’re willing to do some work with it. It covers the basics of things like pursuit, fleeing, collision avoidance, and leader following.