Bullet 2.83 released on github: Example Browser, URDF

Open source Bullet Physics SDK release information
Post Reply
bullet_team
Posts: 16
Joined: Mon Oct 28, 2013 12:18 am

Bullet 2.83 released on github: Example Browser, URDF

Post by bullet_team » Mon May 04, 2015 6:38 am

You can download the Bullet 2.83 release from github here:
https://github.com/bulletphysics/bullet3/releases

See the docs/BulletQuickstart.pdf guide as part of the SDK download.

Some of the features include:
  • A new example browser, based on OpenGL 3+. It is still work-in-progress and not all demos have been ported over yet. Still, it is a better way to explore the Bullet SDK.
  • Import of URDF files, universal robot description files. A URDF file can be imported as rigid bodies (btRigidBody) or as multi body (btMultiBody). See the example browser under importers.
  • Improved support for btMultiBody with multi-degree of freedom mobilizers, thanks to Jakub Stepien. See examples/MultiBody/MultiDofDemo.
  • New btGeneric6DofSpring2Constraint, replacing the old one. Thanks to Gabor PUHR and Tamas Umenhoffer. See the example browser under API or examples/Dof6Spring2Setup.
  • OpenCL demo integrated in the ExampleBrowser. The demo is disabled by default. See docs/BulletQuickstart.pdf how to enable it.
  • Implicit integration of gyroscopic forces. See example browser under API/Gyroscopic for the Dzhanibekov effect.
Please enjoy, and expect improvements in future releases.
Erwin
Last edited by bullet_team on Mon Oct 10, 2016 2:21 am, edited 2 times in total.

DannyChapman
Posts: 81
Joined: Sun Jan 07, 2007 4:29 pm
Location: Oxford, England
Contact:

Re: Bullet 2.83 released on github

Post by DannyChapman » Tue May 05, 2015 1:44 pm

The feature to include the gyro terms in the solver is excellent - it turns out to be really important for correct simulation of aircraft spins and snap rolls etc, so much appreciated. I'll post a video of it in my R/C flight sim shortly.

Thanks - Danny

BluePrintRandom
Posts: 43
Joined: Sun Oct 27, 2013 4:16 am

Re: Bullet 2.83 released on github

Post by BluePrintRandom » Wed May 13, 2015 11:32 pm

Nice!

I wish the Devs @ blender would get this into the game engine.

d3x0r
Posts: 51
Joined: Tue Dec 11, 2012 9:59 pm

Re: Bullet 2.83 released on github

Post by d3x0r » Sat Nov 14, 2015 4:54 am

So what's on the plate for the future? I see some work in featherstone btMultiBody stuff...

I also see some logic for tracking 'islands'.. which I guess are groups of related things that might collide.
I would think that as an extension to that one might order collisions based on their collision with static bodies; such that if a body collides with a static body it gets an additional flag set in it that indicate it's a static collidable; would think that would solve issues stacking heavy things on light things. (been doing a lot of reading and now see where that artifacting comes from). Then the 'roots' of islands would process first and then tree out from there... but maybe then 2 bodies on a static ground next to each other would still have issues.

Also digging through collision dispatch and DISPATCH_CONTINUOUS is never actually used? Isn't that kinda what discretedynamicsworld/CCD would need? to precalculate the penetration depth to determine a more appropriate time step before doing the discrete resolutions?

aaronhansome
Posts: 2
Joined: Wed Mar 16, 2016 3:12 pm

Re: Bullet 2.83 released on github

Post by aaronhansome » Wed Mar 16, 2016 3:28 pm

Any news on this?

Riley
Posts: 1
Joined: Wed Sep 14, 2016 12:55 pm

Re: Bullet 2.83 released on github

Post by Riley » Wed Dec 28, 2016 5:05 pm

d3x0r wrote:So what's on the plate for the future? I see some work in featherstone btMultiBody stuff...

I also see some logic for tracking 'islands'.. which I guess are groups of related things that might collide.
I would think that as an extension my crazybulk review by thisfitlifestyle to that one might order collisions based on their collision with static bodies; such that if a body collides with a static body it gets an additional flag set in it that indicate it's a static collidable; would think that would solve issues stacking heavy things on light things. (been doing a lot of reading and now see where that artifacting comes from). Then the 'roots' of islands would process first and then tree out from there... but maybe then 2 bodies on a static ground next to each other would still have issues.

Also digging through collision dispatch and DISPATCH_CONTINUOUS is never actually used? Isn't that kinda what discretedynamicsworld/CCD would need? to precalculate the penetration depth to determine a more appropriate time step before doing the discrete resolutions?
I wish there was more info out there on this, don't take me wrong github has the read me file but i am lookig for a video tutorial

kownwong
Posts: 2
Joined: Mon Feb 06, 2017 2:20 pm

Re: Bullet 2.83 released on github

Post by kownwong » Sat Feb 18, 2017 2:58 pm

DannyChapman wrote:The feature to include the gyro terms in the solver is excellent - it turns out to be really important for correct simulation of aircraft spins and snap rolls etc, so much appreciated. I'll post a video of it in my R/C flight sim shortly.

Thanks - Danny
Have you posted your video already? If yes, where can I view it?

DannyChapman
Posts: 81
Joined: Sun Jan 07, 2007 4:29 pm
Location: Oxford, England
Contact:

Re: Bullet 2.83 released on github

Post by DannyChapman » Tue Feb 21, 2017 11:06 pm

kownwong wrote:
DannyChapman wrote:The feature to include the gyro terms in the solver is excellent - it turns out to be really important for correct simulation of aircraft spins and snap rolls etc, so much appreciated. I'll post a video of it in my R/C flight sim shortly.

Thanks - Danny
Have you posted your video already? If yes, where can I view it?
Ooops I forgot! https://youtu.be/LwjFUzsymjE

The manoeuvres most affected are the flat spin right at the end of the video, and also the "flips", for example around 2:25 - if they don't start perfectly aligned with the wing span then the glider "wobbles" out after a few rotations (not shown here). Before I included the gyro term it would happily continue to rotate around a slightly "off" axis, which is wrong.

Here's the designer of the plane flying the real thing (including the gyro terms!): https://youtu.be/6VZ0tRrXnKA

kownwong
Posts: 2
Joined: Mon Feb 06, 2017 2:20 pm

Re: Bullet 2.83 released on github

Post by kownwong » Thu Feb 23, 2017 8:08 am

DannyChapman wrote:
kownwong wrote:
DannyChapman wrote:The feature to include the gyro terms in the solver is excellent - it turns out to be really important for correct simulation of aircraft spins and snap rolls etc, so much appreciated. I'll post a video of it in my R/C flight sim shortly.

Thanks - Danny
Have you posted your video already? If yes, where can I view it?
Ooops I forgot! https://youtu.be/LwjFUzsymjE

The manoeuvres most affected are the flat spin right at the end of the video, and also the "flips", for example around 2:25 - if they don't start perfectly aligned with the wing span then the glider "wobbles" out after a few rotations (not shown here). Before I included the gyro term it would happily continue to rotate around a slightly "off" axis, which is wrong.

Here's the designer of the plane flying the real thing (including the gyro terms!): https://youtu.be/6VZ0tRrXnKA
Watched both the videos. All I can say is "Brilliant"!
Last edited by DannyChapman on Thu Feb 23, 2017 10:18 am, edited 1 time in total.
Reason: Removing spam link in quoted text. Had that been inserted intentionally or by accident?!

Post Reply