Search found 89 matches

by hyyou
Fri Jul 20, 2018 10:58 am
Forum: General Bullet Physics Support and Feedback
Topic: Is there a lower limit for velocity in Bullet?
Replies: 4
Views: 451

Re: Is there a lower limit for velocity in Bullet?

You're welcome. XD

I call this for every body every time-step.

Code: Select all

btRigidBody->activate();
by hyyou
Thu Jul 19, 2018 3:04 pm
Forum: General Bullet Physics Support and Feedback
Topic: Is there a lower limit for velocity in Bullet?
Replies: 4
Views: 451

Re: Is there a lower limit for velocity in Bullet?

Body is automatically deactivated if its speed size is too small.
http://www.bulletphysics.org/mediawiki- ... ion_States

(I may insert some code snippet later)
by hyyou
Mon Jul 09, 2018 7:17 am
Forum: General Bullet Physics Support and Feedback
Topic: When building URDF models, which visualizer do you use?
Replies: 3
Views: 587

Re: When building URDF models, which visualizer do you use?

I have just known URDF from your post.
After some search, I found a Blender's addon https://github.com/dfki-ric/phobos. :mrgreen:
From skimming, it looks good and its development is still active. ( but I have never used it yet )
by hyyou
Sat Jun 30, 2018 1:34 am
Forum: General Bullet Physics Support and Feedback
Topic: Using btTriangleShape objects as btCompoundShape children (C++)
Replies: 2
Views: 497

Re: Using btTriangleShape objects as btCompoundShape children (C++)

This line ...... tetrahedralShape0->addChildShape(btTransform(), triangle0); "btTransform()" <----- No initialization constructor is called! Please "setIdentity ()" before you use it. Reference: http://bulletphysics.org/Bullet/BulletFull/classbtTransform.html By the way, I don't think inheriting Bul...
by hyyou
Thu May 10, 2018 2:54 am
Forum: General Bullet Physics Support and Feedback
Topic: Detection of child shape indices in a collision for a compound shape
Replies: 6
Views: 670

Re: Detection of child shape indices in a collision for a compound shape

^ Because of the uninitialized value, I have to remember type of the shape in my own code. Great answer, drleviathan! ... It is also consistent with what I noticed. To reply OP's email, yes, I believe query the "index" is the best way. It is probably the only way. AFAIK, Bullet's API doesn't provide...
by hyyou
Sun Apr 29, 2018 2:18 am
Forum: General Bullet Physics Support and Feedback
Topic: Minimalist game loop with tunneling
Replies: 12
Views: 1166

Re: Minimalist game loop with tunneling

I am out of idea.

I have never faced such problem for the built-in btBoxShape.
Perhaps, it is limitation of btBvhTriangleMeshShape or its margin.
(more info about margin) https://www.youtube.com/watch?v=BGAwRKPlpCw
by hyyou
Fri Apr 06, 2018 2:12 am
Forum: General Bullet Physics Support and Feedback
Topic: btBvhTriangleMeshShape tunneling
Replies: 9
Views: 772

Re: btBvhTriangleMeshShape tunneling

I believe it is very fast, but not sure if it is too fast.

I just noticed that, at some time-steps, it looks like stack of box simulation.
Try to enable "SOLVER_RANDMIZE_ORDER". (http://bulletphysics.org/mediawiki-1.5. ... SolverInfo)

I am curious if it helps.
by hyyou
Thu Apr 05, 2018 2:08 am
Forum: General Bullet Physics Support and Feedback
Topic: btBvhTriangleMeshShape tunneling
Replies: 9
Views: 772

Re: btBvhTriangleMeshShape tunneling

(I will avoid to repeat what drleviathan already mentioned.) Hmm... I feel that the dropping boxs move quite fast. I am curious. How much are their max speed? There is a rumor that the middle parameter of stepSimulation() should be 1. (https://stackoverflow.com/a/21273467) I didn't verify it, but I ...
by hyyou
Tue Apr 03, 2018 12:33 pm
Forum: General Bullet Physics Support and Feedback
Topic: motion state and others
Replies: 5
Views: 743

Re: motion state and others

Thank a lot, drleviathan, for very rich answer!
I gain extra knowledge from your gravity and btConvexHullShape part.
I will follow you everywhere. XD
by hyyou
Mon Apr 02, 2018 1:57 am
Forum: General Bullet Physics Support and Feedback
Topic: motion state and others
Replies: 5
Views: 743

Re: motion state and others

- gravity - what is the proper way of setting correct value of it? To avoid any issue, I set it as (0,0,0) and apply gravity impulse every time-step instead. btQuaternion(0.0f, 0.0f, 0.0f, 1), I read http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-17-quaternions/ btVector3(0, 0, 0) /...
by hyyou
Sat Mar 31, 2018 2:16 am
Forum: General Bullet Physics Support and Feedback
Topic: Mouse picking, rayTest
Replies: 2
Views: 352

Re: Mouse picking, rayTest

Whoo.... the code is so long. Sorry for not read it. I stuck with the same issue. Here is how I solved :- 1. Erase all Graphics code. Erase all mouse-related code. 2. Create empty world. 3. Create 1 very simple btBoxShape & 1 btRigidbody with all 1 mask at position (0,0,0). 4. Try to ray test only 1...
by hyyou
Sat Mar 24, 2018 2:06 am
Forum: General Bullet Physics Support and Feedback
Topic: Integrate simulator with Bullet
Replies: 5
Views: 427

Re: Integrate simulator with Bullet

Thank drleviathan, for the great answer!

On topic:-

OgreBullet (http://wiki.ogre3d.org/OgreBullet) is a popular example.
It aims to integrate a node-based graphic engine (Ogre) with Bullet.
OP may get some neat idea from it. I have never used it though.
by hyyou
Thu Mar 22, 2018 3:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: Integrate simulator with Bullet
Replies: 5
Views: 427

Re: Integrate simulator with Bullet

I use 1 body = 1 node.
Yes, there are still a lot of (fun) work.
by hyyou
Thu Mar 08, 2018 4:00 am
Forum: General Bullet Physics Support and Feedback
Topic: How to move a character? FPS
Replies: 2
Views: 574

Re: How to move a character? FPS

(late reply) I don't know much about Bullet's camera. Bullet's Physics position are usually world-coordinate. By the way, I believe the Graphics part of Bullet is just there for debugging purpose + show-case. If you want to make a FPS, you may also want to code Graphics yourself (raw OpenGl) , or us...
by hyyou
Thu Mar 08, 2018 3:32 am
Forum: General Bullet Physics Support and Feedback
Topic: Predict whether a step will occur
Replies: 4
Views: 447

Re: Predict whether a step will occur

Can you call stepSimulation(customFixedValue) only when "total >= doStepValue" instead?