Search found 85 matches

by DannyChapman
Tue Nov 27, 2012 8:31 pm
Forum: General Bullet Physics Support and Feedback
Topic: Strange behaviour of long rotating bodies
Replies: 10
Views: 4358

Re: Strange behaviour of long rotating bodies

What's your gravity value? If it's around 10, then your objects are absolutely massive - unlike anything you've seen in reality... It is 15, but no matter to what value I set the gravity, bodies still behave the same, except for the fact then everything moves slower of course. I also tried changing...
by DannyChapman
Mon Nov 26, 2012 2:54 pm
Forum: General Bullet Physics Support and Feedback
Topic: Strange behaviour of long rotating bodies
Replies: 10
Views: 4358

Re: Strange behaviour of long rotating bodies

Adam27 wrote:Diameter is 0.5, height is 8. The shorter the cylinders (or capsules, I've tested them as well) are, the less the effect is visible.
What's your gravity value? If it's around 10, then your objects are absolutely massive - unlike anything you've seen in reality...
by DannyChapman
Fri Nov 23, 2012 3:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: Strange behaviour of long rotating bodies
Replies: 10
Views: 4358

Re: Strange behaviour of long rotating bodies

There are two things I think: 1. It's quite usual to drop one of the terms from the integration of rotational motion, because it helps with numerical stability. Without checking, I don't know if Bullet does this. As a result angular velocity gets conserved, but not necessarily angular momentum, and ...
by DannyChapman
Mon Nov 19, 2012 6:19 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Flight Simulator using Bullet
Replies: 8
Views: 11123

Re: Flight Simulator using Bullet

As an update to this, it's now available on iOS as well as Android - more info and links to iTunes/Google Play here:

http://www.rowlhouse.co.uk/PicaSim

Thanks Bullet :)
by DannyChapman
Wed Nov 07, 2012 3:07 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Articulated systems & indep. generalized coordinates
Replies: 6
Views: 4480

Re: Articulated systems & indep. generalized coordinates

Danny - thanks for the speedy reply but I am not sure I understand you correctly: are you saying that PhysX enforces articulation/joint constraints using independent set of coors? I'm saying you should look up the documentation and have a look at the api for what PhysX call Articulations, as it may...
by DannyChapman
Sat Nov 03, 2012 1:24 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Articulated systems & indep. generalized coordinates
Replies: 6
Views: 4480

Re: Articulated systems & indep. generalized coordinates

PhysX 3 contains articulations, which you should look at. They work very well...
by DannyChapman
Sun Aug 19, 2012 12:10 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Learning Pets. Bullet powered Genetics Algorithms.
Replies: 2
Views: 4604

Re: Learning Pets. Bullet powered Genetics Algorithms.

I don't have an iThing, but it looks great - nicely polished :)
by DannyChapman
Mon Jul 23, 2012 5:01 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Flight Simulator using Bullet
Replies: 8
Views: 11123

Re: Flight Simulator using Bullet

Thanks. I'm quite happy to share the aerodynamics/simulation code with anyone (actually, it's really just a tidied up version of the aero code in my earlier Slope Soaring Simulator which is completely open source). Just email! I'm not sure about the whole codebase though... I'm about to add online l...
by DannyChapman
Thu May 17, 2012 11:11 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Flight Simulator using Bullet
Replies: 8
Views: 11123

Flight Simulator using Bullet

A few days ago I released my Android (and iOS soon) app which is a free flight simulator for radio-control planes: https://play.google.com/store/apps/details?id=com.rowlhouse.picasim All the flight dynamics is home grown, but it uses Bullet for the rigid body simulation - so far it's worked very wel...
by DannyChapman
Fri May 04, 2012 2:04 pm
Forum: General Bullet Physics Support and Feedback
Topic: btKinematicCharacterController fundamentally broken?
Replies: 10
Views: 7191

Re: btKinematicCharacterController fundamentally broken?

Dennis Gustafsson made an interesting, slightly (but not hugely!) relevant, post recently:

http://tuxedolabs.blogspot.co.uk/2012/0 ... jumps.html
by DannyChapman
Fri Mar 30, 2012 3:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: Memory leaking in Visual Studio 11
Replies: 3
Views: 2162

Re: Memory leaking in Visual Studio 11

I found something similar (and posted about it too) - it was due to the profiling code. When I disabled that the leaks stopped. I didn't investigate properly though.
by DannyChapman
Thu Dec 22, 2011 9:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: Memory Leak from Linking
Replies: 10
Views: 5074

Re: Memory Leak from Linking

10 seconds later (well, perhaps 20):

Some hunch made me turn off profiling (#define BT_NO_PROFILE 1 in btQuickprof.h) and that got read of this leak.
by DannyChapman
Thu Dec 22, 2011 9:43 pm
Forum: General Bullet Physics Support and Feedback
Topic: Memory Leak from Linking
Replies: 10
Views: 5074

Re: Memory Leak from Linking

I'm getting this too with 2.79. If I do: mGliderGame->mCollisionConfiguration = new btDefaultCollisionConfiguration(); mGliderGame->mDispatcher = new btCollisionDispatcher(mGliderGame->mCollisionConfiguration); mGliderGame->mOverlappingPairCache = new btDbvtBroadphase(); mGliderGame->mSolver = new b...
by DannyChapman
Wed May 18, 2011 12:08 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Objects feel "floaty"
Replies: 4
Views: 2634

Re: Objects feel "floaty"

The reason why physics tech demos tend to feel "floaty" is that they use objects that are much bigger than you'd find in real life. The kind of real objects one is used to see falling (coffee cups, for example) around are typically only a few cm up to maybe 30cm in size. However, physics engines, wh...