Search found 18 matches

by Proctoid
Sun Sep 30, 2007 1:07 pm
Forum: General Bullet Physics Support and Feedback
Topic: Question: Simulating water
Replies: 26
Views: 18670

Re: Question: Simulating water

Scan through all your game objects, if the bodies pos is below the water pos then apply an impulse to the body
- this basic method of applying impulses is also useful for explosion/wind effects etc
by Proctoid
Wed Sep 26, 2007 10:11 am
Forum: General Bullet Physics Support and Feedback
Topic: Collision Response: object, poi... voi?
Replies: 4
Views: 1791

Re: Collision Response: object, poi... voi?

i dunno if the velocities would have changed before the callback is called - not something i've needed to investigate yet...
i just save variables before calling step simulation and compare them after because i don't want to fill callbacks with lots of extra code!
by Proctoid
Tue Sep 25, 2007 7:55 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision Response: object, poi... voi?
Replies: 4
Views: 1791

Re: Collision Response: object, poi... voi?

i play with bullet just for fun, but if accuracy of velocity or speed etc is not so important you could do something simple like i do... during your enviroment creation, set the callback for when manifold points are added: gContactAddedCallback = new_persistent_manifold_collision_point_added; here i...
by Proctoid
Sat Sep 08, 2007 6:55 pm
Forum: Release Announcements
Topic: Bullet 2.57 SDK: new stack/pool memory allocations
Replies: 1
Views: 8761

Re: Bullet 2.57 SDK: new stack/pool memory allocations

thanks for the new update. i had a problem with the compound collision destructor: in btCompoundCollisionAlgorithm::~btCompoundCollisionAlgorithm m_dispatcher was undefined (0xcdcdcdcd) so for now i have modified the constructor: btCompoundCollisionAlgorithm::btCompoundCollisionAlgorithm to do m_dis...
by Proctoid
Sat Sep 08, 2007 5:31 pm
Forum: General Bullet Physics Support and Feedback
Topic: Problem changing the rotation of a kinematic body
Replies: 5
Views: 1986

Re: Problem changing the rotation of a kinematic body

here is the modified BasicDemo.cpp from v257 which shows the bug
by Proctoid
Sat Sep 08, 2007 3:38 pm
Forum: General Bullet Physics Support and Feedback
Topic: Problem changing the rotation of a kinematic body
Replies: 5
Views: 1986

Re: Problem changing the rotation of a kinematic body

Thanks i shall modify one of the demos to replicate the problem - currently ive downloaded the new 2.57 but my vc6 is complaining of new and delete being missing a few hundred times during link stage (LNK2001) so i need to sort that first. for now this is a description of how it was going wrong in v...
by Proctoid
Thu Sep 06, 2007 8:53 pm
Forum: General Bullet Physics Support and Feedback
Topic: Which cylinder is the right cylinder?
Replies: 2
Views: 1265

Re: Which cylinder is the right cylinder?

I do not believe there is any noticible performance difference with whichever cylinder alignment you choose. I tried them all, rotating each physics shapes start orientation to match with the graphic mesh cylinder creation function that i happened to originally code. The same is for all primitives -...
by Proctoid
Fri Aug 31, 2007 9:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: Problem changing the rotation of a kinematic body
Replies: 5
Views: 1986

Problem changing the rotation of a kinematic body

I can change the position of a kinematic body with no problem by reading the current transformation matrix and updating the position and then setting the new transformation. If i change the rotation by a largish step then that is ok too. But, if i do a rotation change that is very small any dynamic ...
by Proctoid
Wed Aug 29, 2007 6:34 pm
Forum: General Bullet Physics Support and Feedback
Topic: Question re AABB dimensions
Replies: 2
Views: 1325

seem ok - looks like that is the 0.04 collision margin being added
by Proctoid
Wed Aug 29, 2007 8:52 am
Forum: General Bullet Physics Support and Feedback
Topic: Objects destruction
Replies: 1
Views: 1323

The general rules is if you create an object it is your responsibility to delete it. If you find deleting something causes a crash then it is easy enough to find the problem. A few minutes spent looking at class constructors and then searching for the particular object variable destruction is simple...
by Proctoid
Wed Aug 29, 2007 8:38 am
Forum: General Bullet Physics Support and Feedback
Topic: Terrain mesh collision
Replies: 11
Views: 3348

The only time i have had things falling through a landscape is when the graphical mesh does not match the physics mesh... ie. i have set the wrong vertices or winding order in part of the mesh i have given to bullet. As erwin suggested you should 'Implement the btIDebugDrawer interface, so that you ...
by Proctoid
Sun Aug 19, 2007 12:41 pm
Forum: Release Announcements
Topic: Bullet 2.56: parallel constraint solver, SPU & multicore
Replies: 3
Views: 13177

2.56 in good old vc6

many thanks for 2.56... fyi, for the old vc6 enviroment i have had to change btmultisapbroadphase source a little bit: 1. in btMultiSapBroadphase::btMultiSapBroadphase constructor, virtual bool needBroadphaseCollision function, i have to add btMultiSapBroadphase:: in front of the four btMultiSapProx...
by Proctoid
Wed Aug 01, 2007 10:14 am
Forum: General Bullet Physics Support and Feedback
Topic: Island grouping and sleeping issues
Replies: 1
Views: 1690

body->setActivationState(DISABLE_DEACTIVATION) will keep a body active
by Proctoid
Sun Jul 22, 2007 10:17 am
Forum: General Bullet Physics Support and Feedback
Topic: Constraint bug with 2.54
Replies: 6
Views: 4406

i use the btDiscreteDynamicsWorld::removeConstraint(btTypedConstraint* constraint) to remove a constraint between two rigid bodies BEFORE removing the rigid bodies and all works fine. take a look at the function if you are doing something different or are not using a btDiscreteDynamicsWorld (btDiscr...
by Proctoid
Fri Oct 13, 2006 9:35 am
Forum: General Bullet Physics Support and Feedback
Topic: tall cylinders in ccdphysics demo
Replies: 2
Views: 2764

tall cylinders in ccdphysics demo

Hi, i have added a 5th shape to the array of shapes in the appccdphysicsdemo which is a cylinder 1x7x1 in size and replaced the brick wall with an x row of this new shape. when they fall over they do not seem to be correct... whatever 'topple over' angle they are at if they are spinning on their bas...