[Joints] Crazy Snake instead of my lamp

Hello everyone,

I'm here because of my snake which is a lamp. I mean, it supposed to be a lamp, so 3 rectangles and 1 triangle with some pivot joints for hold them together. But I certainly missed a step, and now the thing is on the ground with horrific spasms, like a demonic snake which tries to reach a yoghurt river or whatever.

To be precise, here's a small drawing and the action related to it. As you may understand, a rectangle is a link, so several rectangles connected will be a string. But look at these two rectangles with two image point, I make the joint by connecting their image points...isn't that how we're supposed to do it ? What's wrong exactly ?

Guys ? Someone ? Okay I was maybe too specific, in brief, how can I make a realistic string by using joints and physic objects ?

I can join the capx of my previous attempt if you need it (the one with the crazy shit on the ground, be careful I bet this thing want to eat your head or something). I just want to build a physical lamp hanging from the ceiling which reacts well realisticly with another physical object (like my sprite or a rock or I don't know, your favorite duck for instance). You know, this kind of stuff :

The way I see it, it's a movable object (the lamp itself) related to an immovable object (the ceiling) thanks to a pivot joint (the cable). Am I wrong ? If I'm not, why are all my attempts "alive" and "hyperactive" as soon as I define the corresponding joint ? Thanks in advance

Nobody use Chipmunk physic here ? :/

You need to disable the collisions between the objects I think. The simplest way to do that is to make there collision group 1.

Okay this was clever, I wasn't. Indeed, it works ! But the thing still swinging now, like if someone just gave it a little push. Is there a way to make it immobile at the beginning ? Thanks for your answer anyway, it really helped me, as easy as it was x)

Here's a few ways to make a single-segment rope joint:

https://dl.dropboxusercontent.com/u/523 ... oints.capx

I think the slide joint with some kind of rotation damping on the lamp would be my preference - it give you an elastic cable, a bit more interesting than the stiff pivot joint.

It shouldn't swing if everything is centered around the fixed joint.

Here's an example of one way to do it:

https://dl.dropboxusercontent.com/u/542 ... _lamp.capx

Thanks, they are perfect (both of your examples). Just a last thing about yours, R0j0hound. I noticed that your solution results sometimes by a Javascript error "the body is undefined". It's not a real problem because it doesn't concern the place I need to put this lampe, but I still can't figure out why it happens. Any idea ?

You mean my example causes that error? Or in your capx?

In my capx when I use the same technique than in your example

I don't really understand why. It says "the body is undefined" as soon as I use a background (Tile map or Sprite).

I tried on the same layout then in another one (wire and lampe on layout A, Background on layout B), the error still occurs

Posting your .capx will be the quickest way to getting an answer.

If you aren't able to post this .capx - for whatever reason, e.g. NDA - can you recreate in a new one and post that?

Yeah I can't post the URL because I'm new, wow, rude (but understable because spams etc)

Do I have to create a new topic ?

Yeah I can't post the URL because I'm new, wow, rude (but understable because spams etc)

Do I have to create a new topic ?

You can bypass the posting restrictions by inserting characters - asterisk, space etc - in the URL, e.g.

htt*p:/*/ww*w.mysite.com/mygame.capx
[/code:f5g6hjov]

Rofl, I'm not a smart man. Sorry, of course I can, here's the capx :

ht*p://www.mediafire.com/download/pdq0v4n8qi1or8u/JoinTest.capx

As you may notice, it's r0j0hound's example but with a background, which is a sprite on another layout.

I can't even tell which body is "undefined", everything is supposed to be defined already.