tank tracks and elastic

'kay, two questions in one.

http://www.udec.cl/~jfuente_alba/Blast_code.cap

First: I used the offset effect on a sprite to emulate top down tank tracks, but if the offset is negative it just slides away and if there's rotation involved it just goes NUTS!

Tried using a tiled background, but apparently that plugin cannot be rotated :O

Can't figure another way to do this. Any ideas?

Second: it's supposed to be a wrecking ball attached to the tank.

I've set it up so if it's out of a given radius (len_chain global) it will set the speed (Wrecking PV speedx and speedy) towards the body of the tank with a speed that depends on how far it is and an elasticity global. I also added a drag coefficient in the globals. The movement is rather wonky, has anyone a better approach? I want to achieve an elastic behaviour, after a certain distance the elastic should tense and apply force.

Tomorrow I will attempt actual force equation. Too tired now.

Instead of using shader effects I'd use an animation.

http://dl.getdropbox.com/u/666516/speedy.cap

Simulating movement is fairly easy to do, just make as many frames as you have segments of track, and for each frame move one segment down the line.

Yeah, I'd make animation for something so simple...

If you get stuck I can make something for you quickly, it wont be hard...

~Sol

Updated the .cap

Tank tracks look beautiful now used distortion map, doubled the sprite along the tiling direction and uv-scrolled it, resetting to wrap.

Now, I wanna have two tracks on this tank attached each to a point and set their distortions independently. Should I have two different objects with each its own image? or is there a way to manage that with instances? Tank body already has two image points.

Wrecking ball is a wreck, will implement proper elastic physics into it next time.