Pendulum - how?

IsabelleK

I'm making a pendulum:



It's a big actor (both stone circle, and rope are the same actor), it's made that way that the empty end of the line is the middle of the actor.

I have a rule:
If rotation = 45
Interpolate rotation to -45

and

If rotation = -45
Interpolate rotation to 45

It works fine, but sometimes it doesn't choose the quickest way, but rotate around - almost 360 degrees. I just can't find any other simple solution, so it rotates like a pendulum.

Can anyone help me with this?

Thank you!

FloridaGames

Try this:
Add a self.clockwise(boolean)
Rule: If self.clockwise is true:
rotate clockwise.
Otherwise: rotate counterclockwise.

Rule: If self.rotation = 45
Change attribute self.clockwise to true

Rule: If self.rotation = 315
change attribute self.clockwise to false

RThurman

@TheMoonwalls, @uptimistic

Imagine how much simpler all this will be when joints are implemented!

Here is a slightly simpler way of making a pendulum. It will be slightly less processor intensive (than the demo above) -- since its not trying to do verlet integration.

This demo also has the advantage of being able to adjust gravity and acceleration a little easier.

http://www.mediafire.com/download.php?l3mk2io3rzohir1

I sure hope joints come along soon!

IsabelleK

Thanks @uptimistik, and @RThurman!

patrykadas

Hi!

@RThurman

Could you reshare the file? I will appreciate it a lot!

LeonardDeveloper

FMG made one about 2 years ago, a pendulum template for the creator that is; unfortunately we can't access those the templates.

Anyway I'm sure @rthurmans logic was probaply the same anyway!

patrykadas

So is there anywhere a file I could use to know that logic?

LumpApps

Here is the file, credits go to @firemaplegames

RThurman

Here is the requested file. It will be somewhat different from the very excelent FMG method given above.
http://www.mediafire.com/download.php?e3zg477cekl764j

patrykadas

Hello and thank you for your replies!

Although It is not exactly what I have in mind. I don't know why, but firemaplegames' file does not work in my gamesalad.

However, I came with equations like that for ipad landscape pendulum going through centre:

Constrain:

- self.position.x to 160*cos(self.time*200%360)+512
- self.position.y to 40*cos(self.time*400%360)+384

It works fine, however I can't figure out how to do so it could rotate according to it position.

I was thinking about vector to angle like (512-self.position.x, 384 - self.position.y) + offset, but I flips weird and simply does not work.

Any ideas?

Thank you for your support, best community ever.

Socks

. . . but firemaplegames' file does not work in my gamesalad.

Same here, I just get some flashing boxes.

It works fine, however I can't figure out how to do so it could rotate according to it position.

Constrain X to 160*cos( game.Time *200)+512
Constrain Y to 40*cos( game.Time *400)+384
Constrain rotation to 40*cos( game.Time *200)

I've never worked out why people put %360 after the angle+multiplier ? I dumped it as from what I can see it's unneeded baggage.

P.S. your pivot point is a little weird, it's not fixed.

Socks

Yep, just tested, those numbers work:

Quick demo:

http://www.mediafire.com/?271as5qtbzan797

patrykadas

Wow, those indeed works great. Thank you!