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 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
344 views

Best collision shape for rooms

I'm wondering what is the most efficient collision shape to use with APIs like Bullet or Havok for rooms/interiors. Rooms tend to be boxes but are concave since the normals point inward which means no ...
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2answers
778 views

Distance between two objects?

We are trying to determine the distance (a scalar, double) between two objects' surfaces in Bullet. We are new to the Bullet engine, and we've been looking into the demo projects, but couldn't find ...
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1answer
409 views

What is the best Broadphase Interface for moving spheres?

As of now I am working on optimizing the performance of the physics and collision, and as of now I am having some slowdowns on my other computers from my main. I have well over 3000 btSphereShape ...
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1answer
1k views

android game using bullet and libgdx

i'm developing a android project for school and i'm currently using libgdx for rendering. It performs quite well, but it lacks a 3d physics library. So i searched and found that Bullet physics engine ...
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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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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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2answers
1k 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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1answer
292 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
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
212 views

jBullet Collision/Physics not working as expected

Below is the code for one of my objects in the game I am creating (yes although this is a cube, I am not making anything remotely like MineCraft), and my issue is I while the cube will display and is ...
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3answers
401 views

How would I successfully split a vector to increase game performance?

Okay so I have a vector for all of the monsters that are spawned in my game. All of these monsters are in a single vector and are "active" according to what zone they are in relative to the player's ...
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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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0answers
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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0answers
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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0answers
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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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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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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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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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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0answers
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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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
871 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
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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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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0answers
310 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
603 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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1answer
397 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
60 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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1answer
230 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
138 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
150 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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0answers
48 views

Bullet simulation stops after windows inactivate

I am having trouble when inactivating window (event resizing); all the contents get rendered and input works. Even the physics work but the btDiscreteDynamicsWorld stepSimulation function does not get ...
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1answer
1k views

Detect when a bullet rigidbody is on ground

I have a rigidbody that is on top of a plane or another rigidbody. How do I check if said rigidbody is on top of it? I tried to check the Y-part of the velocity but it is never 0, it is always a ...
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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
718 views

how to predict enemy postion to shoot bullet same kingdom rush

i'm doing a tower defense game same kingdom rush, enemy can run curve not only linearly. i found this link : 2D tower defense - A bullet to an enemy but this link use only for enemy run linearly. ...
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1answer
1k views

Bullet physics with OpenGL

I have got some problem implementing bullet physics into my opengl game. The thing is that it doesn't want to update my translatef value continously but only at the end. The code for bullet looks like ...
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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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votes
1answer
679 views

How do I perform collision tests between two 3D oriented bounding boxes?

I want to test two 3D oriented bounding box objects against each other and stop them if there is a hit detected. How can I accomplish this using only the collision detection functions in the Bullet ...
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votes
1answer
56 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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votes
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 ...