Search found 96 matches
- Tue Sep 06, 2016 2:21 am
- Forum: General Bullet Physics Support and Feedback
- Topic: my linked rigid bodies limp, how can I get joints locked
- Replies: 11
- Views: 9876
Re: my linked rigid bodies limp, how can I get joints locked
@drleviathan, thank for the useful link to your thread. There is no way to achieve this using 6Dof's or even btFixedConstraint. Is btFixedConstraint somehow stable than 6Dof? Why? I always thought they were the same. beyond about 5 or 6 Fixed constraints in a single chain it gets noticeably soft. I ...
- Wed Aug 31, 2016 2:30 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Efficiently add/remove objects to/from the dynamics world
- Replies: 7
- Views: 7696
Re: Efficiently add/remove objects to/from the dynamics worl
The official somewhere stated that - try to use primitive if possible ; it is cheaper than triangle mesh. I don't know if it is still applicable for this case. I am using a triangle mesh rigid body instead of a compound body. You use mesh, so you have to modify mesh's shape if terrain is modified, r...
- Tue Aug 30, 2016 2:45 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Efficiently add/remove objects to/from the dynamics world
- Replies: 7
- Views: 7696
Re: Efficiently add/remove objects to/from the dynamics worl
Sorry, I encapsulated Bullet and execute most of Bullet's operation via it.
Thus, it is not trivial to create a test case.
Remove/Re-add is very expensive but not as much as I thought, though.
Thus, it is not trivial to create a test case.
Remove/Re-add is very expensive but not as much as I thought, though.
- Tue Aug 30, 2016 2:40 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: compound shape help
- Replies: 4
- Views: 4918
Re: compound shape help
benelot, for me it is Rigid (simple shape) vs Compound.
I tried to do a merge C1+C2->B, but I forget to disable C1 & C2.
I tried to do a merge C1+C2->B, but I forget to disable C1 & C2.
- Fri Aug 26, 2016 5:07 am
- Forum: General Bullet Physics Support and Feedback
- Topic: compound shape help
- Replies: 4
- Views: 4918
Re: compound shape help
I had this problem once. It was exactly about compound-shape & move-by-itself. To debug, make sure you have only 1 body (the compound) in the world & no gravity. Let's see if it still dare to move by itself. In my case, the velocity came from an invisible collision response, and it was bug i...
- Mon Aug 22, 2016 2:08 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Jittering and shaking when moving a rigidBody
- Replies: 20
- Views: 29060
Re: Jittering and shaking when moving a rigidBody
I am only a beginner, but as far as I know, kinematic is not designed to receive force from automated collision response. I doubt, setting velocity in every frame shouldn't cause jitter, otherwise Bullet would have rather-severe fault/bug. Where did you call set velocity? - hopefully not inside some...
- Fri Aug 19, 2016 2:02 am
- Forum: General Bullet Physics Support and Feedback
- Topic: custom collision response to control the impulse, possible?
- Replies: 0
- Views: 3446
custom collision response to control the impulse, possible?
Does Bullet have any callback that let me override calculation of impulse of some pair of colliding btRigidBody manually? e.g. B C and D are btRigidBody. If I set my special UserData to B & C, when B & C collide each other, it will call my custom collision response similar to this :- collisi...
- Fri Aug 19, 2016 1:48 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Jittering and shaking when moving a rigidBody
- Replies: 20
- Views: 29060
Re: Jittering and shaking when moving a rigidBody
I have never set velocity directly every frame.
I always change velocity by apply impulse, and never encounter any jittering.
If you are hurry, a simple code to reproduce the issue can induce faster and better response from people.
I always change velocity by apply impulse, and never encounter any jittering.
If you are hurry, a simple code to reproduce the issue can induce faster and better response from people.
- Thu Aug 18, 2016 2:30 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: How to create custom constraints?
- Replies: 2
- Views: 3856
How to create custom constraints?
I want to create a new constraint type that work a little different from btGeneric6DofSpring2Constraint. The difference is that user can set (i.e. customize) "mass", "center of mass" and "inertia" (if involved) of body A and B in constraint perspective . For example , T...
- Thu Aug 18, 2016 2:01 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Updating COM every frame?
- Replies: 4
- Views: 5007
Re: Updating COM every frame?
@benelot Constraint is easy, but it is too unstable and expensive. While 1 Compound with 400 simple shapes is reasonably fast (thank developer!), "400 Simple Body + 399 Constraint" is unusably slow and cause explosion from divergence - even with good mass. I tested it with btGeneric6DofSpr...
- Wed Aug 17, 2016 1:39 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Updating COM every frame?
- Replies: 4
- Views: 5007
Re: Updating COM every frame?
I have the exact same problem. Thank you for posting. The solution may appear in Scorpion81's fracture source code in http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=12&t=10883 . I just skimmed it. If you would make some progress, I will greatly appreciate if you share the knowledge. ...
- Tue Aug 16, 2016 4:08 am
- Forum: Physics authoring tools, serialization, standards and related topics
- Topic: Blender Fracture Modifier - Compound Fracture Support
- Replies: 1
- Views: 36866
Re: Blender Fracture Modifier - Compound Fracture Support
Hello, scorpion81 I have played the plugin. It is great and thank for your help in the forum! Now, I am interested in your code and still digging it. Besides the code itself, do you have some document / more description about your modification of Bullet? It will really help my digging process. If yo...
- Mon Aug 15, 2016 12:26 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Forum moderators/custodians/janitors?
- Replies: 6
- Views: 16525
Re: Forum moderators/custodians/janitors?
I second the idea that there should be someone to remove those spams / edit some posts. For example, many KennethTColman's advertisement in April 2016 are not removed, and now it is August 2016 already. More spams will cause newcomers think that this library was abandoned, then they will flee away. ...
- Mon Aug 15, 2016 8:38 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Efficiently add/remove objects to/from the dynamics world
- Replies: 7
- Views: 7696
Re: Efficiently add/remove objects to/from the dynamics worl
I am also facing that same problem as OP, at the exact same lines of code. In my case, "chunk" is a compound body - compose of many child shapes. If I want to add/remove a single child shape from the compound body, or change collision mask, I will have to remove and add the whole body back...
- Fri Jul 15, 2016 11:02 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Is Bullet still in use? Recommended for 2016 new title?
- Replies: 4
- Views: 10096
Re: Is Bullet still in use? Recommended for 2016 new title?
I started to create a C++ game, at the beginning of this year (2016). I have decided to use Bullet Physics. Now, I still don't think it is a bad decision, and my code is around 10000+ lines now. I have little experience in UE, but one of my friends (project manager) tell me that:- I wish my project ...