Algodoo

It used already in all my engines )

Actually, there are simpler ways to prevent an object from rotating (with the magic of scripting). It's actually very simple, and the user needs to know nothing about writing script. Here's the secret trick:

In the script menu, you will see a property called "angle". The numeric value next to it may have an odd looking number, but in most cases it is very close to zero. If that happens to be the case, you can change the value to 0.0 (zero), and at that point you should see little or no rotation of the object (in this case it's a rectangle for a piston). If the value happens to be a long way from zero (say, 1.35 or -2.87, etc) then just leave it alone.

Now the trick is, in order to prevent that value from changing, you simply place curly brackets around it ( for example: {0.0} or {1.78}, etc. Make sure that you use curly brackets and NOT parenthesis.

There is one more thing that you can do to make sure that the object doesn't rotate even under high torque from other objects, and that is to set property called "velocityDamping". You will see three numbers separated by commas and surrounded by square brackets. It should look like this: [0.0,0.0,0.0]. The first value on the left is for X motion damping, the middle is for Y motion damping, and the right is for rotation damping. The range of each value is 0 to 1.0. If you set the rotation damping to 1.0, the object will greatly resist any torque placed on it.

Try it and see if you like it any better than adding a hinge.

lethalsquirrel,

Read this comment.

Xray,

Thanks for sharing the info. I learned something new.

Nice and thanks for the tip s_noonan

Disclaimer: Yes I know this has been done before, Yes I know there are other ways to do this, and yes I have seen Kilinich's suspension scene. that's where I got the idea.

The only reason I posted this is to show people that don't already know about it. And I have never seen a scene demonstrating the use of stretched hinges with pistons.

This is the kind of simple scene that can help people out and spark some creative ideas.

This might be a noob question but, how do you make a stretched hinge?

tone121 - You should SEARCH for answers before asking questions. That's the difference between a "noob" and someone who knows how to find things. Now, just to be nice, I did the search for you, and found THIS

Hope this helps!