Constrain to a rotating actor

Zombiebrains

Hi guys

I have a problem with the main part my hero graphic setup.

I have a bullet that sits on top of a old six shooter gun (So here are 6 empty holes).

I have created a new bullet graphic that sits on top of this gun.

When you tap on the bullet to fire it, the whole graphic of the gun rotates, like it has been fired but the problem I have is that I want the bullet to re-chamber over the hole it was over when it was fired, which since it was, has rotated to another position.

So, the gun sits at x=70 / y=70

The bullet sits at x=70 / y =108

Is it possible to constrain an actor to a point on a rotating actor?

Zombiebrains

I've tried again today to try and get the bullet to sit above the empty chamber but to no avail.

I can get it to stick to it without the gun sprite rotating but when you fire the bullet (Tap on it) the gun chamber rotates to but the next bullet at the12 o'clock position, this obviously has then moved the empty chamber clockwise so now I need the bullet to appear where it was fired.

Any help would be really appriciated as this bit is holding up my progress...

Thanks guys

Rob2

Not sure if I understand you but http://gamesalad.com/forums/topic.php?id=5744#post-36386
and http://gamesalad.com/forums/topic.php?id=20867 might help.

This diag covers a lot http://gamesalad.com/forums/topic.php?id=19860#post-151044

Zombiebrains

Hi Rob

Thanks for showing me those threads...that's great and I think that will help me out tremendously.

Thanks a million!

mu-kowAPPS

hmm....

when i say chamber, i mean the entire 6 slot actor

something like

constrain self position x to: game.chamber x + cos(game.chamber angle%360)*40
constrain self position y to: game.chamber y + cos(game.chamber angle%360)*40
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40 is just an arbitrary number i chose. adjust those to make the actor closer or farther from the center of the main chamber.

as for the other 5 bullets,

maybe use the same formulas but (game.chamber angle+45)%360

not sure how well this would all work, but worth a shot. good luck!

Zombiebrains

Hey, thanks Dstier for the extra tuition...I'll give that ago and report my progress back to the forums.

mu-kowAPPS

ohhh i made a mistake, when you constrain self.position y you should use sin instead of cos.

also, for the other 5 bullets, i think if you have the first slot at 0 degrees (to the right). then instead of +45, i think it would be +60. and the others would be +120,+180,+240,+300 in that order

that should do it!

Zombiebrains

Thanks mate, I'll use those setting and let you know how it pans out.

Zombiebrains

Hi Dsteir

I have a problem...

I've gone to my first bullet and started to enter your code - CHANGE ATTRIBUTE....then I hit a problem...

Chamber (or my real actors name is 'Right Gold-Six-Shooter-Empty') does not appear in the second window on the CHANGE ATTRIBUTE panel.

I have successfully entered the first part - constrain self position x to: but when I go to GAME/ get actor its not in the drop down...as this only shows attributes set up and not actors...

What am I doing wrong?

mu-kowAPPS

Well. I think I know the problem.

You will need to make a new game attribute to represent the chamber angle

Just make The new attribute real. Name it whatever. I'll just say chamber angle

Then go to Ur chamber actor and constrain game.chamber angle to self.rotation

Then u will have access to the game.chamber angle attribute u need!

Zombiebrains

Thanks dstier,

I'll give that a go...:)

Zombiebrains

Hi dstier

nope...nothing is happening.

The bullet is staying at it's 12 o'clock position and not moving around.

I have attached a screenshot from my first level showing the six shooter in the bottom left. The orbs float up, as you can see there is a orange one on screen.



I've set up a REAL attribute called Sixshooter

Here is the constrain instructions I've put on the red bullet (clicked on the red bullet on the scene, not in the actor section)



Can you see where I might have gone wrong?

mu-kowAPPS

I see it very quickly.

U will need to make 3 game attributes total to make this work.
Sixshooter x
Sixshooter y
Sixshooter angle

In the sixshooter actor, constrain game.sixshooter x to self.position x
Constrain game.sixshooter y self.position y
Constrain game.sixshooter angle to self.rotation

Then...

In the bullet actor

Put the rules I told you. What u did wrong up there is that you just added the y manually after the actual attribute. Same with angle. I can tell because its not highlighted in blue.

Also, 12 o clock isnt zero degrees. 3 o clock is zero degrees. 12 o clock is 90 degrees so in the bullet actor u will put

Constrain self.position x to game.sixshooter x + cos((game.sixshooter angle + 90)%360)*40
Constrain self.position y to game.sixshooter y + sin((game.sixshooter angle + 90)%360)*40

This will work if done right. I'm using these same formulas in the game I'm working on now.

Zombiebrains

Hiya

Excellent stuff...I'll try that out and let you know

Zombiebrains

Hi Dstier

Thank you so so much

That worked a treat and now all the bullets stay in their original postion as the sixshooter rotates with each shot.

Had to tweak some of the numbers to line up the bullets ver the holes exactly but that wasn't a big problem...all works great now so can crack on with the game again.

Your a star and thank you for working out the formulas...I would have never worked that out!!!

mu-kowAPPS

Thank you, your welcome and good luck with your game!