Turn the geometry (be it a rectangle or circle) to static = false and give it a mass.
To make it swing like the Server Farm balance, add a hinge and make its "body1" equal the name of the geometry.

what if i don't give a hinge? will it be like an unmovable blockhead?

edit: is there a way to make objects that can only be passed by geometry?

http://goofans.com/developers/world-of-goo-level-editor/reference-guide/...

You mean, make a geometry that allows other geometries to pass through, while Goo Balls are blocked by it? If so, yes, just set nogeomcollisions=true in the geometry's properties in World of Goo Level Editor. Likewise, you can set it contacts=false in order to let ALL objects pass through, be the objects Goo Balls or other geometries.

re: your no-hinge question: If you make a nonstatic geometry without a hinge, it'll be free to move wherever it wants (Imagine a rectangle or circle without a hinge like you would a ball or block of wood- in real life, you can move it wherever you want), meaning it'll fall down, tumble around, etc. (think of the free-moving green crates in Deliverance). It's the hinge that makes it NOT move freely. There's a hinge on the head in YouHaveToExplodeTheHead that makes it stay put (just rotate).
But I don't need to explain all this. There's a whole developer FAQ and all the info you need in the link that DaB just showed. Just poke around there to find the info you need.
Good luck!

Thanks!

so, i tried to make a level that has a trap in it (inspired by Gotcha!), and it has similar mechanics like the red carpet

http://img822.imageshack.us/i/wogle1.png/

but it failed, anything i did wrong? (still new at this)
the goal is to make the player assume that he/she needs beauty balls to complete the level (right now it doesn't), and so the player will build to the beauty ball, but when the structure hits the beauty ball, then the beauty ball will roll over and tip off the domino rectangles, with the small one falling into the lever, which will elevate a deadly square to a 10000 force linear force field, killing the goos on its path. all objects have very light mass, the longer domino having 5 mass, the small one 10 mass, the "buttons" on both sides has 0.1 and the lever has 0.2 mass.

some help please?

There are 2 problems:

1) All geometries need to have a mass > 1.

2) The force field might be too big, try making it only have 1,000 force.

The level looks cool, I want to see it when it's finished!

Even a 100 force would be fine. Gravity itself is really powerful, and is only has a force of 10.
Overall, looks good. I'd recommend a fairly light mass on all dominoes and the lever pieces and such, so a mass of 5 or so for all of them would be a good idea. You'll need to experiment a bit to get all the values correct, and be sure to place the Beauty close enough to the starter domino so that a slight nudge will topple them over. You may also want to make your dominoes pretty thin so they'll topple easily. And yes, the last domino should have a higher mass so it can move the lever easier.
One small caveat: the "killer" block will also need to be heavier, since a light block can be stopped easily, maybe after just hitting one small goo. To counter this, you may want to make a small movable pin (like in the Gotcha level), but what I'd recommend is changing the linearforcefield to geomonly = true and make the right edge come all the way over to where the Beauty ball is. That way, the block will be pushed the entire way over. But overall, great idea, I'm looking forward to some cool physics simulations in this level. Keep up the great work!

Oh, yeah, also make sure you have a hinge in the middle of the lever so that it'll act like a lever. And you have a couple guiding rails on the right side for the counterweight, make sure you make similar guiders on the left. You might even want to turn the lever's property contacts=false so that it isn't affected by the guider blocks and make those blocks extend all the way down. As you're tinkering with getting the setup working properly, making visualdebug=true in the level tree is very helpful at times.
Good luck!

If you can't get it working, go ahead and upload it someplace and provide us with an upload link, so we can help you fix it.

Thanks for the advice!

But i switched the lever mechanism to a linear force field that travels around the exterior level (i'm SO sorry you had you go through all that explanation, but i'll be sure to try them on my next level), and it works, but sometimes the killer block goes out of the way (it goes to the upper direction), so i tried to make a geometry on the upper direction and set contacts=false so that goos can pass, and nogeomcollision=false so the killer block can't pass and be funneled there. I wonder, does this work? (a geometry that lets goos pass but other geometries can't pass)

oh and, normal pipes suck beauty balls to right?

-once again, Thanks, and Sorry

I'm not sure it's possible to make a geometry that only goos can pass. What you CAN do is make a small linear force field to push it back onto the track, with geomonly="true". And, yes, normal pipes suck beauty balls--you can have any color pipe filter any types of goo. The filtering is controlled by the levelexit.

Hey, no problem, I can just be long-winded sometimes.
Glad to know that you were able to think of an alternate solution, and yeah, ^^ what AP said.

If you're talking about "cool" as in the graphics, then you're about to be disappointed because the graphics are seriously bad

Does that mean the position of the hinge can affect the object when there are no second geometry to hinge? And, if there is a second geometry hinged, does it hinge at a point where both geometries meet? Or not?

And, some a couple more questions:
- what happens when a geometry with tag "geomkiller" collides with a geometry with the same tag?
- is it possible to create a geometry that can resist "geomkiller", but it is solid to the geometry with "geomkiller"? (meaning the geomkiller can't pass through the geometry, quite contradicting actually)

Sorry for "necroing" a thread, I just didn't find it appropriate to start a new thread, since I made one recently with a roughly same context

If 2 geomkillers collide, only one of them will explode. Daft as Brush says that you can't predict which one that will be.

Geomkillers can only kill dynamic geometries. If you just make a static, solid rectangle, the geomkiller block will just bounce off it. If you want a static block that can be geomkilled, just make it dynamic and give it 2 hinges. These will stop it from falling or rotating or moving.

does the 2 hinges have to be located on strategic locations of the geometry? (like the corners and sides) or can I just randomly place them?

How about: a dynamic block is pushed with a force of say, 10, and it collides with a geomkiller, then will the geomkiller be pushed or will it stay put as if nothing hit it?

Oh yeah, and I noticed that if goos are inside geometries, then it will just act bugged right? I was wondering on how to make "cages" containing goos, but the goos can move freely inside the "cage"

-Thanks! Sorry for asking to many questions, I just couldn't get the hang of these things. Hope you understand...

The 2 hinges can be placed anywhere, but it helps if they're a bit apart. Hinges are a bit buggy, and can be "twisted" and "stretched" sometimes (put all but one fish on the telescope in Observatory Observation Station and watch as the hinges explode).

If the geomkiller were static, nothing would happen. If it were dynamic and light, it would go flying. Either way, the first block would blow up.

You can make a compositegeom to hold the goos. Try copying the one from Upper Shaft and filling it with Goo Products.