Search found 144 matches

by mi076
Mon Jun 11, 2012 6:14 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Moons - Android free toy - Bullet / OpenGLES2
Replies: 0
Views: 3009

Moons - Android free toy - Bullet / OpenGLES2

just uploaded... engine is stable, gameplay is beta

https://play.google.com/store/apps/deta ... okk.solsys
device-2012-06-11-145118.png
device-2012-06-11-145118.png (51.69 KiB) Viewed 3009 times
device-2012-06-11-144908.png
device-2012-06-11-144908.png (35.64 KiB) Viewed 3009 times
thank you for looking at it!!
by mi076
Fri May 25, 2012 10:57 am
Forum: General Bullet Physics Support and Feedback
Topic: Patch for btQuantizedBvh when compiling with gcc
Replies: 1
Views: 1693

Re: Patch for btQuantizedBvh when compiling with gcc

Have you opened an issue? I looked at C++ standard (open-std.org) and so far "<<" is undefined if on left side is negative value.
There is also one in btSoftBodyConcaveCollisionAlgorithm.h (line 48).
Thank you.
by mi076
Sun Mar 25, 2012 3:38 am
Forum: General Bullet Physics Support and Feedback
Topic: Arrow flight modeling
Replies: 5
Views: 3388

Re: Arrow flight modeling

btCylinderShape *capsule = new btCylinderShape(btVector3(0,0.5,0)); you have to give the bounding box values for cylinder shape, no zeros here... I have tried to move the center of mass, but it does nothing, bullet cant have a center of mass that is not the center of the shape (at least that is wha...
by mi076
Sat Mar 17, 2012 7:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: Allowing objects to accelerate differentl using gravity
Replies: 1
Views: 1308

Re: Allowing objects to accelerate differentl using gravity

Is there an easy way to approximate this in the bullet engine? the easiest way is to set linear/angular damping... To get more accurate results write some approximation of fluid resistance.. http://en.wikipedia.org/wiki/Drag_equation btScalar Cdrag = 0.5f * m_drag_coef * m_area * m_air_dens; btVect...
by mi076
Sat Mar 17, 2012 5:50 pm
Forum: General Bullet Physics Support and Feedback
Topic: Constraints and collisions cause instant crash.
Replies: 5
Views: 3374

Re: Constraints and collisions cause instant crash.

I have improved the safety of my allocations but it did not help. as far i can see you still allocate sizeof(CLASSNAME) memory for things like Core->dispatcher = new(Core->dispatcher) btCollisionDispatcher(Core->collisionConfiguration); ... it is wrong. Use aligned allocator. There is one in Bullet...
by mi076
Sat Mar 17, 2012 12:28 am
Forum: General Bullet Physics Support and Feedback
Topic: Constraints and collisions cause instant crash.
Replies: 5
Views: 3374

Re: Constraints and collisions cause instant crash.

there is a 50% chance that the step simulation call crash with access violation not tested the code above, so not sure is the way trying to go good or not in general, but in particular it might be memory alignment issue... the idea.. (from btSimpleBroadphase.cpp) void* mem = btAlignedAlloc(sizeof(b...
by mi076
Sun Jan 29, 2012 4:10 am
Forum: General Bullet Physics Support and Feedback
Topic: Dropping an object from different heights
Replies: 8
Views: 3392

Re: Dropping an object from different heights

What you get with getAppliedImpulse() is the recently applied impulse to satisfy contact constraints, it is not what you need. Anyway, you could also try to switch m_dynamicsWorld->getSolverInfo().m_splitImpulse = 1 / 0 in your experiments. Also you are calculating force=impulse/timeStep. It doesn't...
by mi076
Sat Jan 28, 2012 10:35 am
Forum: General Bullet Physics Support and Feedback
Topic: Per shape collision group
Replies: 4
Views: 2520

Re: Per shape collision group

I have body with btCompoundShape, which contains many shapes. ... Our bodies can contain btBvhTriangleMeshShape. afaik btBvhTriangleMeshShape is not supported as child shape for compound, gimpact too.... (use convex hull). You can also use several submeshes in mesh shapes instead. Collision tests r...
by mi076
Sat Jan 28, 2012 10:28 am
Forum: General Bullet Physics Support and Feedback
Topic: Can RayTest be ignored for particular collision object?
Replies: 3
Views: 2163

Re: Can RayTest be ignored for particular collision object?

for example like here, look for #ifdef USE_GHOST_OBJ_WITH_VEHICLE.. (BTW, word "ghost" doesn't mean Bullet ghost object, it can be any collision object). struct MyVehicleRayResultCallback : public btCollisionWorld::ClosestRayResultCallback { const btCollisionShape * m_hitTriangleShape; int m_hitTria...
by mi076
Wed Jan 18, 2012 12:56 pm
Forum: General Bullet Physics Support and Feedback
Topic: Contact point changes depending on height
Replies: 18
Views: 6301

Re: Contact point changes depending on height

i mean m_dynamicsWorld->stepSimulation(ms / 1000000.f,1,1./120.);
(not necessary 1 max substep)
by mi076
Wed Jan 18, 2012 12:55 pm
Forum: General Bullet Physics Support and Feedback
Topic: Car riding around a cylinder
Replies: 1
Views: 1949

Re: Car riding around a cylinder

but btRaycastVehicle does not support adding forces, nor disabling gravity. vehicle's chassis is a rigid body and you can apply forces or disable gravity. Where and how apply force depends on kind of force... To use some custom gravity model you may try to apply gravity per object. I have experimen...
by mi076
Wed Jan 18, 2012 12:01 pm
Forum: General Bullet Physics Support and Feedback
Topic: Contact point changes depending on height
Replies: 18
Views: 6301

Re: Contact point changes depending on height

body->setCcdMotionThreshold(0.00001); body->setCcdSweptSphereRadius(0.00001f); Not sure ccd motion clamp will help here, more likely it will harm, specially with the above values (microscopic squared velocity threshold and embedded sphere radius of 1/100000 m for 18 m sphere). Try increase internal...
by mi076
Sun Dec 25, 2011 5:34 am
Forum: General Bullet Physics Support and Feedback
Topic: stepSim twice per frame, gravity wrong but model size ok
Replies: 3
Views: 2017

Re: stepSim twice per frame, gravity wrong but model size ok

I'm setting gravity to -9.81, as gravity should be and to just test whether the simulation is running at a realistic speed, dropping a car from 490.5 units up. With 1 unit = 1 meter the car should take bang on 10 seconds to hit the ground. This isn't happening. Can not confirm. Droping something fr...
by mi076
Fri Dec 02, 2011 5:05 am
Forum: Physics authoring tools, serialization, standards and related topics
Topic: blender exporter
Replies: 3
Views: 4087

Re: blender exporter

afaik, only via controller
by mi076
Thu Dec 01, 2011 1:10 pm
Forum: Physics authoring tools, serialization, standards and related topics
Topic: blender exporter
Replies: 3
Views: 4087

Re: blender exporter

this

Code: Select all

PhysicsConstraints.exportBulletFile("test.bullet")
works with 2.60a... may be there are better ways, don't know

http://bulletphysics.org/Bullet/phpBB3/ ... f=9&t=6683