Alice in New York PHYSICS

Games
#1

Hello community!

I’m learning how to develop interactive books for iPad like Alice in New York.

I’ve been banging my head against the wall for almost a month now. The problems i’m having with are objects that have to move around a pivot point to specific limits and then return into original position. That’s the case with Alice.

I tried to achieve the result by combining pivot and wheel joints. It works almost like it should. There’s no problems if you quickly drag and release alice’s body so it rotates for a few degrees and then rotates back to it’s original position. The problem is when you drag alice’s body offcenter and than don’t release. The wheel joints starts to pull alice back into original position. And to make things worse, when you decide to release alice’s body who has now already returned into original position, the touch joint “kicks” alice into opposite direction.
The effect i would like to achieve is that you drag/rotate alice’s body to a certain limit/degree and than only when you release, alice goes back to it’s original position. Again if you have the app you can check it out otherwise tell me and i’ll make a movie.

Similar story with the birds. If you quickly drag and release them everything works fine. But if you drag them and don’t release them immediately 2 wheel joints start to pull the bird back into it’s original position. And then when you release, the touch joint kicks the bird into opposite direction.

I uploaded the whole scene on this link: http://www.aliansa54.com/beta/1/archive.zip

I would really appreciate all the help i can get!
Thanks, Nick [import]uid: 77183 topic_id: 17911 reply_id: 317911[/import]

#2

anyone? [import]uid: 77183 topic_id: 17911 reply_id: 69575[/import]

#3

Is there a bug in the Box2D implementation? looking at aliceWheelJoint isMotorEnabled returns false. And its motor values return 0. Seems like you should be able to toggle isMotorEnabled on an off to get the desired effect. [import]uid: 27183 topic_id: 17911 reply_id: 69626[/import]

#4

I tried toggling isMotorEnabled on and off and it has no effect on the joint. I also tried changing “myJoint.motorSpeed” and there’s also no difference. You think this is a bug? [import]uid: 77183 topic_id: 17911 reply_id: 69702[/import]

#5

Seems odd to me otherwise. Shouldn’t the wheel joint be disabled if isMotorEnabled is set to false? I’d file a bug and see what Ansca reports back with. [import]uid: 27183 topic_id: 17911 reply_id: 69726[/import]

#6

I have just filled a bug (case #9930). Lets hope for the best! Thank you very much for your help! [import]uid: 77183 topic_id: 17911 reply_id: 69875[/import]

#7

cool let’s see what they say. [import]uid: 27183 topic_id: 17911 reply_id: 69884[/import]

#8

2 weeks from reporting a bug and still no reply from Ansca team…is that normal? [import]uid: 77183 topic_id: 17911 reply_id: 72883[/import]

#9

I don’t know what’s normal. Some bugs I’ve reported months ago with no response/fix, others fixed in a matter of days.

How soon they fix it probably depends on a lot of factors: what they’re working on at the moment, how easy it is to debug, how critical it is, how much you’re paying them, :slight_smile: etc.

I usually have to great creative and figure a workaround or alter my plans if it’s time critical. [import]uid: 27183 topic_id: 17911 reply_id: 72890[/import]