Pivot Joints and apparent elasticity

Games
#121

Wow, I think turning continuous physics off might have done the trick! I’m still testing but so far I haven’t seen any ragdoll dismemberment in my game. I did notice one instance where tunneling was an issue so I’ll have to work around that, but I’m pretty sure I know what to do about it.

This thread reminds me of my wife’s labor with our first child; Long and drawn out, no one got any sleep for days, lots of screaming near the end, but with a wonderful result!

Thanks again for looking at this Walter. Be sure to let us know if you find any other undocumented Corona features :wink:

[import]uid: 9422 topic_id: 3208 reply_id: 110897[/import]

#122

Hy Walter!

Here is the link to new thread…http://developer.anscamobile.com/forum/2012/06/08/wheel-joint-problems

I really appreciate your help!
Nick [import]uid: 77183 topic_id: 3208 reply_id: 110914[/import]

#123

Wow, I’ve just re-read this thread since it had become dormant last year and just want to say, my very first post on this forum was about the exact same topic, lol

Here was my silly little experiments with physics when I first started using Corona. Since that time, I’m on my way to making a game based on what was done here (a rag doll arm for hitting flies)

https://developer.anscamobile.com/forum/2011/10/18/controlremove-joint-elasticty

Anyways since then I’ve resolved the problem despite my rather unnatural application of corona physics. I still use touch joints and I tween them, but I’m always ensuring I never tween them past the point where the joints start separating.

It would be nice to alter the physics meter-pixel ratio as my physics objects are in ranges of 30-100 in pixel length. My current partial rag doll is a skyscraper. Having to scale things down will cause a lot of headaches when instantiating my world which I’ve pretty much completed. I look forward to being able to change the touch joint mass, but I’m happy with the results I’m currently getting despite this persistent problem. Sad to hear so many ppl out there are having problems, I too would like to see physics take a higher priority over something like a level editor.

A good house needs a solid foundation, software development is no different, I’m pleased with the priorities on bug fixing that Ansca has been taking. Hopefully the physics issue will be resolved before the Summer is over. fingers crossed [import]uid: 88628 topic_id: 3208 reply_id: 111290[/import]

#124

Please please *please* put this physics.setContinuous trick in the docs - specifically the docs for pivots. It took me a month until I finally found this thread and now my stuff works as it should. [import]uid: 160496 topic_id: 3208 reply_id: 119268[/import]

#125

It is in the docs: http://docs.coronalabs.com/api/library/physics/setContinuous.html

Oh, you mean the joint guide (http://developer.coronalabs.com/content/game-edition-physics-joints)? I just added a link. [import]uid: 26 topic_id: 3208 reply_id: 119270[/import]

#126

walter, I mean in big, friendly letters in the physics-joints docs, at the top, put something that basically explains that if you’re having problems with elasticity in the joints, use the physics.setContinuous(false). Would save some developers hours of fiddling with stuff, at least. [import]uid: 160496 topic_id: 3208 reply_id: 119279[/import]

#127

Agreed. This needs to be very very clearly put into the joint docs in jumbo sized font. [import]uid: 94309 topic_id: 3208 reply_id: 119284[/import]

#128

While setting continuous to false does solve the joint elasticity problem, it causesed many other issues for me with collisions. I had to switch it back on and live with the elasticity. Would be great if there was some way of switching this off only for joints.

#129

It’s unsettling that the only solution to this problem with joints is to set physics.setContinuous to false. While it does seem to solve the elasticity problem (almost), it’s at quite a cost.

Forgive me if this is the wrong thread to bring this up on, but I still have the issue of joints simply breaking (both bodies begin shaking and their bond is effectively removed) when put under enough stress. I am using cliche wrecking ball scenario, where a somewhat dense ball is supported by less-dense chain links. My goal is to simulate a yo-yo, in which case the “wrecking ball” may travel at a relatively high velocity compared to the anchor at the other end of the chain. The argument that the physics engine is subject problems similar to the real world seems valid, but I am not able to achieve velocities nearly great as those that I can in the real world without the chain breaking. I’m hoping that a joint that can’t be broken is at least a possibility in the game world.

Sorry if my wrecking ball/yo-yo mixed metaphor is confusing. Does anyone have any suggestions on how make a joint unbreakable?

#130

While setting continuous to false does solve the joint elasticity problem, it causesed many other issues for me with collisions. I had to switch it back on and live with the elasticity. Would be great if there was some way of switching this off only for joints.

#131

It’s unsettling that the only solution to this problem with joints is to set physics.setContinuous to false. While it does seem to solve the elasticity problem (almost), it’s at quite a cost.

Forgive me if this is the wrong thread to bring this up on, but I still have the issue of joints simply breaking (both bodies begin shaking and their bond is effectively removed) when put under enough stress. I am using cliche wrecking ball scenario, where a somewhat dense ball is supported by less-dense chain links. My goal is to simulate a yo-yo, in which case the “wrecking ball” may travel at a relatively high velocity compared to the anchor at the other end of the chain. The argument that the physics engine is subject problems similar to the real world seems valid, but I am not able to achieve velocities nearly great as those that I can in the real world without the chain breaking. I’m hoping that a joint that can’t be broken is at least a possibility in the game world.

Sorry if my wrecking ball/yo-yo mixed metaphor is confusing. Does anyone have any suggestions on how make a joint unbreakable?