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New to FP. And, of course, questions

Topics: Developer Forum
Jul 24, 2010 at 7:21 PM

Hi everyone!

Scouting the XNA community forums I found info about this particular physics engine, and I pretty much thought that it could help me with a little project I am undertaking.

One thing I urgently need to know: despite the fact that it's still under development, is there any kind of documentation for FP3.0 (besides diving into the code, that is)? I am guiding myself more or less with the 2.1.3 documentation available, but certain things are very different, so any help will be welcome.

Also, even though most of the examples I've found use the 2D horizontal scrolling perspective, my project is a top-down game. I suppose that FP will be helpful nevertheless, but, just in case (and to avoid refactoring and adapting code again), would you recommend me FP, or maybe another engine? Since it's top-down, it's not that I need full physics support, it's basically collision detection, but some thingies in my game follow uniformly accelerated linear motion, and that's where it may come in handy (Plus, building the collision detection by myself started to be a pain in the ass).

I guess that for now, that's everything I need to know.

Thanks in advance! :D

Jul 25, 2010 at 3:29 AM

Top-down physics is basically the same, just without gravity. You can also apply drag to make objects slow down after a certain time.

Have a look at the first example and try steering the car around:

Jul 25, 2010 at 7:10 AM

I am making a top down shooter using Farseer and it works wonderfully. Im in the process of changing it over to 3.0 from 2.1.*

If you have any questions ask away.

My game, ASCII Dungeon Shooter can be seen at


Jul 25, 2010 at 11:36 AM

Right now I'm working my way out from the examples I've downloaded (except they're for FP2.1.*). More or less what I've understood is that everything is a "Body", and Bodies are in the World. I hope I don't have to change my initial scheme for the game (or, at least, change it too much) to adapt it to the engine, but when I have concrete questions, I'll ask

Thanks a lot!

Jul 26, 2010 at 11:36 PM
Edited Jul 26, 2010 at 11:37 PM

So, OK, let me see if I got this straight... what in the past (FP2.1.*) was a PhysicsSimulator, in the present (FP3) is the World, and what once were Body + Shape + Geom, now they are Body + Shape + Fixture.


And I could basically split the game in half: one side does the physics, and the other side does the graphics. This may be a stupid question, but, it's possible to directly change the position of the bodies, right? Not by applying impulse or force, but plainly by changing their coordinates, I mean.



Jul 26, 2010 at 11:45 PM
Yeah. You can use body.position to change the position of the body.