Physics Simulation Forum

Hey guys, my project now features better integration with Bullet. Prior to a week ago, I wasn't feeding Bullet linear and angular velocities, instead I controlled ships via Ogre::SceneNode->yaw pitch and roll. And movement was handled by Ogre::SceneNode->translate(Vector3); Now I apply torques and impulses. The result is a much better experience, collisions are much more realistic, there is a loss or gain of momentum (based on mass of colliding objects ofcourse) and objects can rotate as a result of collisions. The ship controls also feel more realistic and smoother since ships don't stop instantly when the command to turn stops.

So I hope that my project now better represents the awesome capabilities of the Bullet physics engine.

Here's a bit of a before/after video of the physics improvements:
http://www.youtube.com/watch?v=-xk-Yu8QS88

The game also got a bit of a graphics overhaul, and now has tutorials

Here are some updated screen shots:






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I'm using Bullet physics for collision detection and dynamics in my project using Bullet physics. It is a space sim with real time strategy elements. You can play using your joystick or mouse. You can download it on my site http://www.arrmaytey.com. This is a prototype release so I hope that there will be many others with more features, better graphics, and of course improved physics.

The rendering engine is Ogre (you can see other details of the project and other open source tech used on my site if you are interested). For physics I'm using Bullet (with BtOgre). It was a struggle getting other physics engines to even give me demos (tried Ogre Newt, ODE among others). With Bullet I was able to get the Visual Studio projects to run with ease and then with BtOgre the integration took place. At first I used collision only in my project and that was the real turning point of it becoming a game. Once collision detection was in, ships finally became real, could damage other ships and be destroyed. Later I went put in the dynamics responses of Bullet as well.

I'm using a bit of a hybrid system, where sometimes I force Ogre scene nodes to take their positions and orientations from Bullet, and sometimes the Bullet objects get their positions and orientatsions from Ogre.


I hope you download, enjoy and give me some feedback. Thanks

From the video I see that the AI doesn't seem to be trying to dodges the fires.

Is that on purpose or do you plan on working on that ?

Nice look so far btw.

thanks for the commetns

You are right the AI doesn't do any sort of dodging or avoidance.

The fighter ships are meant to be unmanned drones that are part AI and part piloted from the carrier or base they are launched from (in in game universe terms), so they are basically fearless killing machines.

The other larger ships have crews so they should be a bit concerned with their lives. Eventually the AI will have fully fleshed out dispositions: aggressive, defensive, and evasive, which will trigger them running for their lives or standing toe to toe until death.

However the thing is that dodging these projectiles is very hard because the game has what I call "semi newtonian" physics or "simplified newtonian physics" (basically means that there is no drag, no fricksion and no gravity), so just because you change direction doesn't mean you changed your momentum, so the bullet will most likely still hit you (since its moving 10 to 20 times faster than you already). This is actually a fairly big concern of mine, because it means that the player can't dodge real well meaning that the player may feel dismayed at piloting the ship. "argh this is useless I'm getting hit! I can't dodge! this ship is useless! this game sucks!" What I'm planning on doing is giving the player an "afterburner" or some sort of faster thrusting aparatus so that they can accelerate faster thus dodge better.

Updated first post with news of better physics integration and other changes.