It’s been a while since I updated on the old Liberty Engine so here it is with a lot more polish than the last demo. You still can’t modify the objects or forces just yet, but I sharpened up everything else. It’s running much more efficiently, with stats, an improved console and new keyboard commands. It also includes a “Help” button that will explain all of its functions on mouse-over.

Here is a swf copy as well as an exe. I haven’t seen much of a performance difference between the two:

• liberty-engine-demo-041708.swf
• liberty-engine-demo-041708.exe

The default “memory” setting is 60 seconds, so if you play more than 60 seconds it will begin deleting old data. This is meant to prevent the program from filling your computers memory and lagging or crashing. However, you can set the memory value to Infinity and see how much you can hold without slowdown. I found a loss of about 2 or 3 fps with 1 hour of data. I average about 6 or 7 calculated seconds per actual second (Scalc/S) so you should be able to set the rate of time passage to as high as 6 without playback time ever passing up calculation time. But play around with it and let me know how it runs on your machine. I could use the feedback!

With your time rate set to 6, you can get through an hour of simulation in 10 minutes.

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Update: The Liberty Engine: Running Clean

I’ve been all damn talk for too long. Ladies and gentlemen, I give you, the Liberty Engine Demo!

CONTROLS:

-Click the scrolling play button (or press space) to pause the animation.

-“In” and “Out” values determine number of seconds into the animation that the loop will begin and end.

-“Rate” determines the speed at which time will pass (seconds per second).

-“Duration” is the duration of the loop. If modified, it will automatically change the “Out” value.

-All forces in the system are set to enact at the 10 second mark and all calculations end at the 30 second mark.

Aside from the animation controls, this is not an interactive demo. Interactivity will probably be in the next one, but this demonstrates all of the engine principles. You’ll notice a slight lag period just as the swf loads. That’s because it is calculating all of the physics for the entire animation during the first frame. It saves all of that data and then replays it based on the passage of time. That’s why you can scroll back and forth or play at different rates (super slow-motion or fast-forward). The animation is actually set to 40fps, but I guarantee your browser can’t keep up with that speed. Fortunately, because the engine is time based rather than frame based, dropped frames do not effect the rate of movement. Oh, and by the way this is in AS2. I’ll translate it to AS3 later.

I haven’t mentioned the Liberty Engine up here very much, but it’s been a project of mine for over a year now. The concept behind the Liberty Engine is to create a physics engine that ANYONE can use; to liberate the thousands of young game developers without the programming or mathematical know-how to build the kind of games they dream of and provide it for public use free of charge. I hope, with a powerful and easy-to-use engine like this one, to foster a serious indie gaming movement at the grassroots level.

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