Bullet is a professional, free 3D Game Multiphysics Library that provides state of the art collision detection, soft body and rigid body dynamics.

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Bullet btGImpactCollisionAlgorithm

I have a question about Bullet and in particular GImpact. When, the collisiontestpair(a, b) is called where GImpact pair check algo will be called on the btGImpactMeshShape, does it do a AABB tree ...
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7 views

doll lift by applying force and gravity force [duplicate]

Iwant to lift the doll by applying force to box rigidbody. Doll has a few rigidbody and constraint. Then set gravity ZERO, don't work well. please tell me!
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30 views

doll lift by applying force and gravity force, and these are balanced

Iwant to lift the doll by applying force to box rigidbody and these are balanced. Doll has a few rigidbody and constraint. Then set gravity ZERO, don't work well. please tell me!
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27 views

Is it possible to write a simple hitscan weapon code and mod it into a racing game such as Assetto Corsa [closed]

I'm not a programmer and my knowledge of computer games are quite limited. I want to know if it is possible to mod a simple hitscan weapon on to the cars of a racing game would be like. Of course the ...
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1answer
51 views

Bullet Physics - Collision not working when moving btBvhTriangleMeshShape

I have a robot (btTriangleMeshShape for each component) and a chain of boxes used as a cable, which is anchored on two components of the robot. I want to rotate a robot component and when this ...
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1answer
56 views

How to Load a Level for use with the Bullet Physics Library

I am trying to use a level in .obj format loaded with Assimp to generate a btBvhTriangleMeshShape to use with the Bullet physics library. I can successfully load btConvexHullShapes as well ...
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1answer
62 views

unity3d - Fire bullet using AddForce is very slow

This is a top-down view but in 3D coordinates, I would like to instantiate and fire a bullet from the player's gun. This script is on a spawner object at the end of the barrel. void Fire () { ...
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1answer
79 views

Improving performance for flocking behavior?

I have a game that I am trying to make. It is a twin-stick shooter that I want to design to have a LOT (Up to 500) of enemies on the screen. The game's base design comes from that of Geometry Wars, ...
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19 views

JBullet Capsule falls through Plane when Capsule is translated

I am using JBullet (Bullet physics, Java port) and for a player I have a Capsule shaped rigidbody and am translating it for movement (rigidbody.translate()). I even have the dynamicsWorld call ...
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66 views

server/client architecture, how to combine physics data, scene graph and database over the network?

I'm writting a C++ server and a C++ client for a rpg game. The client is using OpenSceneGraph for rendering the 3D. RakNet is used for communication between the client and server. At this time, the ...
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28 views

JBullet Only Updates Position when I update it in Code

The title is a bit weird...but here it goes: I have JBullet configured so that I can move things in my code, as the game tick structure is something like this (the update code located in ...
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1answer
52 views

JBullet move object rigidbody in code?

I am trying to move an object's Transform (of a coded class, these are for the rendering engine), then convert it into a JBullet Transform. After that, I try to apply any movement to the JBullet ...
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78 views

Using Blender to define physics objects for libGDX

I'm in the early stages of building a game using libGDX. The game is 3D and will use Bullet physics (gdx-bullet wrapper). I have a 3D scene loaded and have manually created some physics objects which ...
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21 views

Launching projectile from a “canon” [duplicate]

I'm working on "Scorched earth"-like game just for learning purpose. I can't figure out how to launch the projectile from my tank's position, with a power of X ([0,100]),at an angle of Y ([-180,180]). ...
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37 views

How can motion/simulation be suspended for a given orientation of the body in bullet physics?

I am currently trying to make a Ragdoll and it falls to the ground obeying constraints as expected but it never actually comes to rest. The rigid bodies appear to vibrate and the Ragdoll starts moving ...
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23 views

Java JBullet rotating rendered rigidbodies

Hello I wan't to rotate object I wrote some piece of code but that don't won't to work. Here is this code: glPushMatrix(); float[] matrix = new float[16]; ...
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1answer
96 views

Java JBullet Mesh collsion problem

I have a problem with JBullet mesh collsion. Everything works fine when I create a mesh from my object without scaling, but the problem starts when I want to scale the object. I also tried scaling in ...
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116 views

Projectile Delta Movement

I'm running into an issue where I can't get the Projectiles to travel in the right direction, I'll admit my trig is a little rusty, anyone know how below might be improved? I am trying to get the ...
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1answer
190 views

Bullet Physics - scaling

I have added Bullet to my game engine. So far I am using translation and rotation, and it works fine. But now, I want to scale my geometry (eg. user can drink some potion an became small :-)). I am ...
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142 views

Bullet Physics for Collision Detection and Smooth Response

I'm creating a game using LibGDX, and to prevent the need to spend lots of time writing collision detection code I've decided to make use of Bullet Physics, simply for collision detection and not for ...
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144 views

Trying to bounce a box with a plane using bullet physics

I'm trying to simulate a box that bounces with a plane and I'm beginner with bullet physics. I created a plane (box) and and a box that is falling. The problem is the ball is stalled while colliding ...
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1answer
46 views

Understanding HingeConstraint in jBullet

I'm using the java port of BulletPhysics engine jBullet. I'd like to make a joints between 2 triangles so that one edge of the first and one edge of the seconds act like a hinge. But I don't ...
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1answer
55 views

Bullet pointer becoming zero [closed]

I am currently trying to implement the Bullet physics into my game project. However, when i add some rigid bodies to the scene, i occasionally get an error in btDbvtBroadphase.cpp at the line ...
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73 views

How to get yaw of bullet physics vehicle?

I am using the Bullet Physics port to java, JBullet, and am trying to render a vehicle body that i created in Blender on top of the vehicle chassis. Since i cannot effectively find a way to render ...
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1answer
117 views

How can I get a 4x4 matrix from a bullet quaternion?

I'm trying to make a game using JavaScript with Ammo.js ( an implementation of bullet ) and Sylvester to do my matrix maths. The problem is I don't know how to turn the WXYZ that bullet gives into the ...
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1answer
229 views

In a TPS, how to aim bullets to the direction the camera is pointing, but make the shooting from the player?

(In C#/XNA.) I mean, I can't find an answer nowhere. I'm trying to learn how to make a Third Person Shooter, especially like the one I found in a game called "M.A.R.S.", from Epic Games. I don't want ...
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1answer
116 views

Multiplayer and creeps (NPC enemies): how to compute bullet hits given the lag?

We are making a multiplayer co-op game, where players will shoot not each other but AI enemies (creeps), controlled by the game. The chosen implementation is client-server with an authoritative ...
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1answer
285 views

Friction not working for Vehicle in BulletPhysics

I am creating a vehicle using bullet-physics engine (v 2.82). I created a ground ( btBoxShape ), a box and a vehicle (following the demo). But friction between ground and vehicle wheels seems not ...
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2answers
111 views

Libgdx, find Vector3 direction

I am using Libgdx along with Bullet physics. I have a vehicle moving. I would like to use a ray from the vehicles origin and in the vehicles forward direction. How can I create the forward Vector3 ...
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1answer
186 views

Bullet - objects falling through

I have problem with bullet collisions. You can see problem on this video (around 0:18): http://goo.gl/DiVP8l Objects are "embeded" inside vertical bars - that is not correct - they should be ...
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2answers
431 views

What torque should I apply in Bullet to maintain a vertical orientation?

I have a RigidBody in Bullet. Each frame, I want to apply torque to correct its orientation toward an upright position (i.e. near-zero pitch and roll). I know its angular velocity and orientation. ...
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1answer
115 views

Irregular oval collision detection

I am using a physics library based on the Bullet physics engine. How do I create an egg shaped object or a cylinder where the width differs from the depth (i.e. with an oval shape)? I'm not looking ...
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150 views

JBullet quaternion to Euler angle conversion causes strange flipping behavior

I am making a game using JBullet (a Java port of C++'s Bullet library) for the physics and LWJGL for the graphics. However, JBullet measures angles in quaternions and LWJGL uses Euler or ...
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1answer
318 views

How can I use imprecise accelerometer data for controls?

I want to rotate an object with respect to the phone's position. I use the accelerometer output to detect orientation: float roll = Gdx.input.getRoll(); float pitch = Gdx.input.getPitch(); float ...
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1answer
289 views

Bullet 3D Physics Objects Not Rotating?

So I've got Bullet 3D controlling the motion of objects rendered with DirectX. In the clipping below I've got 2 identical rectangles & 5 balls. The lowest rectangle has a mass of 0 and doesn't ...
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2answers
550 views

How to implement a simple bullet trajectory

I searched and searched and although it's a fair simple question, I don't find the proper answer but general ideas (which I already have). I have a top-down game and I want to implement a gun which ...
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51 views

Bullet Physics ConvexDecomposition?

I've looked at Bullet Physics ConvexComposition Demo and would like to implement that in my game but the code is so undescriptive and it's hard to understand what is going on. Would any of you people ...
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1answer
215 views

Using Bullet physics engine to find the moment of object contact before penetration

I would like to use Bullet Physics engine to simulate the objects in 3D world. One of the objects in the world will move using the position from 3D mouse control. I will call it "Mouse Object" and ...
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2answers
607 views

LibGDX - draw bullet physics bounding box

I am very new to game development and I am trying to debug my 3d collision bounds. Could somebody give me an example on how to draw the collision bounds of an object in libGDX? I assume it has ...
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1answer
45 views

Bullet: Get steepness or slope between positions

In a CharacterController object, there is setMaxSlope(btScalar slopeRadians) The max slope determines the maximum angle that the controller can walk up. But how about knowing it in advance? Like ...
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0answers
202 views

Quaternion - rotating rigidBody to particular angle over time

Using Bullet Physics. There's a rigid body that is rotated. For some delta-time I need to rotate that body to have rotation of (0, y, 0) - keep the old y value rotation but reset x and z. The ...
2
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1answer
534 views

Conceptual - What is the optimal way to combine steering behaviors with rigid body physics?

I am working on a simple 3D space simulator that makes use of the Bullet physics engine. The spaceships are rigid bodies that have a mass and hitbox so that they can be considered for collisions. At ...
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1answer
131 views

Bullet softbody nodes messed up positions [closed]

I recently switched from Havok physics to Bullet because I wanted to have soft body collisions, but I don't have any budget to license the (superior?) Havok solution, I couldn't even try those ...
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1answer
191 views

What are the parameters for btHingeConstraint::setLimit

What does each parameter in btHingeConstraint::setLimit do to the hinge constraint? void btHingeConstraint::setLimit ( btScalar low, btScalar high, btScalar _softness = ...
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1answer
101 views

Bullet3: Issue with applying force once an object is at rest

I just started using bullet and I'm having an issue where once my rigid body is at reset at the floor it won't move when I apply a force to it. I have created a small demo to show this using the ...
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1answer
497 views

How to draw a plane equivalent to a given btStaticPlaneShape using OpenGL

With all other shapes in bullet, you can easily get the transform from the MotionState which holds the origin, the scale, and the rotation. There seems to be no way to get the same information about a ...
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1answer
104 views

x-inverted obj importer in BulletSharp - whats wrong?

See importer C# code at the repository. Screenshot: Left: bullet imported version, right: correct 3ds max version. It's somehow inverted. If you think that left part is just 180 degrees rotated you ...
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1answer
176 views

making rigid body stop using friction

how am I suppose to apply friction to an object so that when I apply force it decelerates eventually to zero? Here are my physics objects: Rigid Body "Sphere" Collision shape: btSphereShape(0.50) ...
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2answers
283 views

Spherical / Relative Gravity

I'm working on an Ogre3D + Bullet project that involves planets in a solar system. For all intents and purposes, I'm looking to give each planet it's own gravity sphere. So far, all I've found are ...
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1answer
493 views

How to use Bullet physics with Entity Component Systems?

I have an Entity Component system and I want to have a Physics Component that would add the given object to the physics simulation. My problem arises because the Bullet API requires me to add each ...