Search found 99 matches

by lunkhound
Thu May 21, 2015 9:18 pm
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

Here is a screenshot of what the new version of the demo looks like: bullet-example-browser.jpg Here is the profile view in single threaded mode, followed by multi-threaded: bullet-example-browser-single-threaded.jpg bullet-example-browser-tbb.jpg My machine has a quad-core CPU with hyperthreading, ...
by lunkhound
Thu May 21, 2015 1:02 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

I just put up a new version of CPU multithreading for Bullet 2 on github. This verison is based on the latest version of Bullet 2.83 on github. Changes compared to previous: - The Multithreaded Demo is now built into the example browser (its under "experimental"). - Microsoft PPL support added (only...
by lunkhound
Sun Feb 15, 2015 9:41 am
Forum: General Bullet Physics Support and Feedback
Topic: Scientific and Technical Academy Award for Bullet Physics!
Replies: 8
Views: 4573

Re: Scientific and Technical Academy Award for Bullet Physic

Nice speech Erwin.

And thanks for sharing your hobby! :)
by lunkhound
Sat Jan 17, 2015 8:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

If you are converting to the concurrency PPL (Parallel Patterns Library) in MSVC, you'd be better off looking at the TBB code since PPL is a virtual carbon copy of TBB. The "schedule(static, 50)" part corresponds to the "partitioner" and grainsize in TBB/PPL terms. They are just for performance tuni...
by lunkhound
Fri Jan 16, 2015 10:07 pm
Forum: General Bullet Physics Support and Feedback
Topic: Correct way to delete constraints if rigid body will be dele
Replies: 5
Views: 4287

Re: Correct way to delete constraints if rigid body will be

Well it seems to me that Bullet was designed with the assumption that client applications are going to have some type of wrapper-object for each Bullet object. That's why each Bullet object has a user-pointer, to make it very easy to map from the Bullet object to the wrapper class. And it's quite ea...
by lunkhound
Fri Jan 16, 2015 7:49 pm
Forum: General Bullet Physics Support and Feedback
Topic: Correct way to delete constraints if rigid body will be dele
Replies: 5
Views: 4287

Re: Correct way to delete constraints if rigid body will be

Correct. That is what I am doing. But to identify and get the correct joint from the rigid body I use the the the constraint reference. Like Erwin is does. Look at the link in the first post. Yes I saw the thread you linked to. Those constraint references only get added to the bodies when you are d...
by lunkhound
Fri Jan 16, 2015 6:45 pm
Forum: General Bullet Physics Support and Feedback
Topic: Correct way to delete constraints if rigid body will be dele
Replies: 5
Views: 4287

Re: Correct way to delete constraints if rigid body will be

This is my understanding: Since the constraint holds pointers to the rigid bodies it constrains, you need to remove the constraint first with world->removeConstraint( constraint ); before deleting either of the objects. Otherwise the constraint will have dangling pointers to those objects. Once the ...
by lunkhound
Fri Jan 16, 2015 11:17 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

raytesting against a gimpact mesh does not seem thread safe i'm getting a crash at btConvexPolyhedron::testContainment during a call to malloc that's all the informations I have for now Thanks for the info. However, I haven't been able to reproduce it. I also looked at the code for btConvexPolyhedr...
by lunkhound
Sat Jan 10, 2015 7:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

Ok so I have nailed down what could cause a crash when we don't enable BT_NO_PROFILE sometime two colliding gimpactmesh will cause the profiler to go in an infinite recursion since I enabeled BT_NO_PROFILE the issue went away Thanks for the update. What's odd is that Cmake should have taken care of...
by lunkhound
Thu Jan 08, 2015 3:33 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

I need to multithread several completely-independent simulations in the same program. (Not the same simulation. Independent ones). Is this possible? For running in the same process, I have doubts. If there is any code being used that reads and writes a static or global data structure, then it likel...
by lunkhound
Thu Jan 08, 2015 3:24 am
Forum: General Bullet Physics Support and Feedback
Topic: Terrain collision - what am I missing?
Replies: 9
Views: 11644

Re: Terrain collision - what am I missing?

There is another thread on this issue http://bulletphysics.org/Bullet/phpBB3/ ... =9&t=10224 where I describe how I solved this problem.

1. Turn on CCD.
2. Use a contact-added callback to flip the normals if they are colliding with the back sides of triangles.
by lunkhound
Fri Jan 02, 2015 8:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: Simulating tracked vehicles
Replies: 2
Views: 2558

Re: Simulating tracked vehicles

I have read about simulating conveyor belts with bullet, which goes in the right direction. But as far as I understand, they always go to a target tangential speed. In my scenario, the speed should be limited by the maximum torque that can be supplied by the vehicle's engine, so the available torqu...
by lunkhound
Tue Dec 30, 2014 3:02 am
Forum: General Bullet Physics Support and Feedback
Topic: CCD & Trigger Objects
Replies: 2
Views: 1774

Re: CCD & Trigger Objects

Instead of making trigger objects, just trace the path of your shots with ray tests.
by lunkhound
Sun Dec 28, 2014 8:54 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

I need to multithread several completely-independent simulations in the same program. (Not the same simulation. Independent ones). Is this possible? Well you could run them in separate processes, and that would surely work. For running in the same process, I have doubts. If there is any code being ...
by lunkhound
Fri Dec 26, 2014 8:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 85547

Re: CPU multithreading is working!

EDIT in this version is it possible to ray cast from multiple thread ? Yes, I fixed a threadsafe issue ( here ) in the DbvtBroadphase rayTest. Raytests are used in createPredictiveContacts which runs in parallel now. There may be (and probably are) more code paths that aren't threadsafe (like the G...