Search found 96 matches

by hyyou
Thu Oct 10, 2019 2:00 am
Forum: PyBullet Support and Feedback
Topic: Intrinsic Matrix for simulated camera
Replies: 2
Views: 830

Re: Intrinsic Matrix for simulated camera

I studied coordinate conversion model coordinate --> world coordinate --> view coordinate --> projected coordinate. ... from here: https://solarianprogrammer.com/2013/05/22/opengl-101-matrices-projection-view-model/ If you get projected coordinate, then multiply it by screen resolution, you will get...
by hyyou
Mon Jul 29, 2019 5:19 am
Forum: General Bullet Physics Support and Feedback
Topic: New to bullet, can't get VS to generate & build?
Replies: 1
Views: 549

Re: New to bullet, can't get VS to generate & build?

Try this :- Solution Explorer > select all Bullet projects > Properties > (don't forget to select "All Configurations") > Configuration Properties > General > Platform Toolset > select "v141". Or just retarget Bullet projects. I believe it is right-click -> retarget. By the way, your post already sh...
by hyyou
Mon Jul 15, 2019 9:37 am
Forum: General Bullet Physics Support and Feedback
Topic: Heap Corruption?
Replies: 4
Views: 716

Re: Heap Corruption?

Thank for sharing. It is interesting discovery.

Did you use WinDbg?
by hyyou
Sun Jul 07, 2019 6:41 am
Forum: General Bullet Physics Support and Feedback
Topic: Question in Bullet source code.
Replies: 3
Views: 2101

Re: Question in Bullet source code.

(necro this old thread) I am curious, so I begin to dig into the source (https://github.com/bulletphysics/bullet3/blob/master/src/BulletCollision/CollisionDispatch/btBoxBoxDetector.cpp). First, it uses separation theorem. Then, it selects the direction (in separation theorem) that yield the least ov...
by hyyou
Mon Jun 10, 2019 4:13 am
Forum: General Bullet Physics Support and Feedback
Topic: How to detect collision for an animated deforming mesh?
Replies: 5
Views: 720

Re: How to detect collision for an animated deforming mesh?

What is multiple keyframed RigidBodies? You can change shape of the rabbit rigidbody (e.g. every 10 timesteps). For example, when it is jumping, two legs may be pop out a lot from the main body. ➨ create an approximate compound shape "A" When it is sitting, two legs may embed into the main body. ➨ ...
by hyyou
Wed Mar 27, 2019 11:05 am
Forum: General Bullet Physics Support and Feedback
Topic: Strange Behaviour in Release Only
Replies: 6
Views: 894

Re: Strange Behaviour in Release Only

probably uninitialized value in some fields of btTransform

In C++, a variable that is not assigned to any value will usually be = 0, but only in debug mode.
In release mode, it will usually be an ugly random value.
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: 1039

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: 1039

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: 1318

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: 954

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: 1410

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: 2503

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: 1741

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: 1741

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 ...