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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Soft body plasticity using Bullet Physics

I made this post on the Bullet forum(link), but the forum is slow so I'm just copying the text from there. Hello, I'm currently working on a game and I want to make certain surfaces of the game ...
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1answer
547 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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21 views

Bullet Physics: 2dArray into Collisionshape

I'm fairly new to bullet physics and I am wondering how to make a collisionshape out of an 2dArray(x,y) with height informations. I figured out I have to use either btBvhTriangleMeshShape or ...
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14 views

btCompoundShape representation of a table not functioning normally

I've been working on a small "game" on the side to develop my game programming knowledge. I put game in quotations because there's really no objective, it's basically just a room filled with tables ...
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1answer
46 views

BulletPhysics ship rotation

First of all, I'm a beginner in game physics, and I think this is a relatively easy problem that I'm not grasping. Short Version: I have a box(representing a ship on water) going forward with a ...
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1answer
16 views

Bullet Physics Applying Torques Effects not noticeable

I am applying torques to a rag doll in order to make it move/walk. For some reason, I am unable to view any effects when I use a call to rigidbody to apply torques even though these torques are ...
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1answer
399 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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1answer
94 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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25 views

What are the best bullet collision detection methods for FPS games? [duplicate]

Bullets are too fast and can be represented as points. Common collision detection methods, like the ones using bounding volumes, may not be suitable. What would be the best for this work. Edit: this ...
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1answer
106 views

Bullet Physics: Difference between Motion State and World Transform

In Bullet Physics, when I create a new btRigidBody, one of the parameters passed to the constructor is the btMotionState, which defines the initial pose of the body. However, if I then later want to ...
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1answer
96 views

Bullet: No Bouncing off the walls

I'm using Bullet Physics for Collision Detection in a first person game. The collision basically work fine, I cannot walk through objects. But if I walk against the wall and release the key I get ...
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20 views

Problem with automatic ragdoll shape generation using Bullet

I'm trying to automatically generate ragdoll colliders (for now, box colliders) from my mesh. First of all, I specify the body parts like so: ragdoll.setRagdollBone(Ragdoll.RagdollBodyPart....
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12 views

Update constraint pivot position in world space in Bullet Physics

The task is: we have N rigid bodies connected with each other by point-to-point constraint. In every frame we have new position of point where first rigid should be attached in world space. How to ...
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2answers
4k views

how get collision callback of two specific objects using bullet physics?

I have got problem implementing collision callback into my project. I would like to have detection between two specific objects. I have got normall collision but I want one object to stop or change ...
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1answer
31 views

Bullet: Apply any Transformation to RigidBody?

I'm using Bullet for CollisionDetection. I load a scene from a Collada-File using Assimp. Let's say I want to give every object in the scene a RigidBody with a box as CollisionShape. Right now I first ...
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2answers
128 views

Gravity too weak

I am using Bullet Physics and the gravity in my world seems to be too weak. This means that items fall too slowly and general values don't make as much sense as they should. While I know that "...
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0answers
51 views

JBullet is acting weird, what is causing these 'floating' rigidbodies?

I've been working on a 3D game engine in Java for a school project. The game engine had scenes containing game objects, these game objects contain components defining the behavior of each object. I'm ...
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0answers
20 views

JBullet & LWJGL Rendering objects with jbullet transform

I tried to render objects with jbullet matrix transform. Its something like that: get float array where is stored matrix then put it to floatbuffer and load to Matrix4f using load() function. Use ...
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4answers
439 views

Should the bullet trajectory calculated by server or by client? [duplicate]

In a FPS game like Battlefield or Arma, when playing online, should the bullet trajectory be calculated by the server or by the client?
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32 views

How to make btSoftBody and btMultiBody coexist in one bullet physics world?

I followed Featherstone demo in Bullet Physics SDK, and SoftBody demo, I succeded to make them work in Irrlicht but, the Featherstone demo needs btMultiBodyWorld and the Softbody needs ...
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1answer
111 views

Bullet Physics / OpenGL Meshes Not Colliding

This is for a school project, and I'm having a bit of trouble with Bullet acting strangely. I have an OpenGL project with Bullet Physics library working with Assimp model loaders and Magick++ ...
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0answers
77 views

Bullet Physics: Applying a force at the point of collision

Suppose I want to simulate some kind of gripper with two "fingers" (such as pair of pliers, or two-fingered robot hand), picking up an object from the ground. Both the gripper and the object are ...
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1answer
85 views

Bullet Physics Collision is Not Detected

I have created two btConvexTriangleMeshShape objects. One is a cube of size (0.1 x 0.1 x 0.1), and the other is is a plane of size (1.0, 0.1, 1.0). The plane is static, and the cube is dynamic, and ...
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1answer
204 views

Why do Physics Engines use collision margins?

When using a physics engine in a game (such as Bullet), you usually need to define a collision margin for each object. I'm a beginner to game development, and I don't understand the purpose of a ...
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1answer
57 views

how to set in vector float x y coordinates [closed]

i am use eclipse java android i am try to projectile trajectory in my game like angry birds example here http://blog.gemserk.com/2012/07/03/drawing-a-projectile-trajectory-like-angry-birds-using-...
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1answer
343 views

What are “frame A” and “frame B” in btGeneric6DofConstraint's constructor for?

I have a very simple (and maybe too primitive to post here but I’ll try anyway :P) question about Bullet constraints. What are arguments const btTransform &frameInA, const btTransform &...
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1answer
466 views

Bullet physics weird behavior. Jittering and drifting with btBoxShape

I'm dropping a simple box onto a plane from 100 units and my solution using Bullet Physics is giving me some weird behavior. The dimensions of the box are {2, 4, 1}. When the box hits the ground it ...
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1answer
272 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 ...
2
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1answer
156 views

Is restitution the wrong value, to make bouncing objects?

I have been experimenting with Bullet. Specifically I was modifying the Hello World tutorial, to make the ball bouncing. The first thing I noticed is, that I need to set both the restitution of the ...
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0answers
255 views

Java 3D collision detection with JBullet

So I have spent a long time trying to work on a collision detection system from scratch for own game engine and came up fruitless due to lack of time. Finally I decided to try to use Jbullet to try to ...
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55 views

Simulate a velocity sensor attached to a softbody node with bullet physics

I try to implement a virtual three-axis velocity sensor attached to a softbody node. The node already provides it's global position, normal and velocity, but how to calculate it's local velocity to ...
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1answer
100 views

issue with ray/physics collision detection

All, I am trying to pick object using ray collision and bullet physics I am initializing my projection and view matrix only once, here is the code projectionMatrix = glm::perspective(90.0f, 4.0f ...
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1answer
45 views

Bullet Physic: Stack transformations on body after adding

How can I stack multiple transformations on a body? I mean... Rotate, translate and then rotate again? If I understood, a transformation on a rigid body can be made like this: btTransform ...
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34 views

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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2answers
3k views

How to set the object's world position in bullet?

In my Ogre3d application I am first changing the parent of a node like this: // save object "Cube" into node*; then ... Vector3 absPos(node->_getDerivedPosition()); Quaternion absOrient(node->...
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1answer
374 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 happens,...
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1answer
120 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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1answer
882 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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0answers
119 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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0answers
23 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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3answers
1k views

Can I change shape of a rigid body after it created in Bullet3D?

I'm beginning Bullet3D. Can I change collision shape of a rigid body after it created? A rigid body accepts a collision shape when it's creating, but it's hard to find options changes the collision ...
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1answer
178 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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0answers
169 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
807 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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2answers
164 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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0answers
312 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
95 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 if(...
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1answer
307 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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1answer
208 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
456 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 ...