Box2D is an open-source rigid-body 2D physics simulation library for games, written in C++.

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Chain Shape Collision

I am facing a new problem by using chain shape. The collision between two chain shape bodies doesn't happen as the collision between normal bodies. So is this normal behaviour or am i doing anything ...
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3answers
258 views

Box2D body jitters when colliding with static body

I am developing a game where a body is moved within the scene using touch. The scene has a boundary wall made up of static rectangular bodies. When I move the object along the boundaries, on ...
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1answer
456 views

Error using Physics Body Editor for LibGDX

In my game, I've been trying to use the physics body editor for libgdx, but I kept on getting an error. So I thought there was probably something wrong with my code so I took the example off of the ...
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216 views

Camera scrolling and game boundaries

I am making a platformer game in JBox2D and LWJGL that has a scrolling camera, but I have hit a wall with the boundaries of the camera. Essentially what I have right now is a Box2D world that is ...
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1answer
206 views

Transforms in Box2D

I'm attempting to implement a camera in my game. I had it working for regular objects, but I began using Box2D and obviously things changed a bit. I have a Body object that I want to draw at the ...
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174 views

Image Texture Tracing Algorithm - Cocos2D Box2D

Context: I am working on a 2D Destructible Terrain engine for Cocos2D with Box2D. All images, when a level loads, have their border's traced and cached for the purposes of forming Box2D b2EdgeShape ...
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1answer
75 views

Starter love2d physics program not working

I am starting out with my first love2d (using LöVE 0.8) physics program. I am just creating some ground/floor, a car body and attaching two wheels with revolute joints and setting the motors a-go. ...
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188 views

Is it a good idea to use box2d to control sprite movement in a 2D game?

I'm trying to use Box2D to control sprite movement.Some burning issues are these: 1.When I trying to move the sprite on a slope or a lean barrier. The sprite will move off the slope which is not what ...
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109 views

Is it possible to apply a texture inside a GL_LINE_LOOP?

I am creating a game using Box2D and OpenGL ES 1.1. I am taking the b2PolygonShape vertices and converting them into an OpenGL ES 1.1 GL_LINE_LOOP. The debugging view looks great, but now I want to ...
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392 views

C++ SFML Box2D - Somewhat confused when it comes to syncing phyisical body with a render body

While testing Box2D with SFML I encountered something which confuses me: The relation between physical body centroids and SFML's sprite origin. As an example I have a test class GameObject which is ...
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611 views

2D Destructible Terrain with Box2D / Cocos2D -> Image Tracing

Bear with me as this will be a rather lengthy post. For the last month I have been working on an open source Cocos2D, Box2D Destructible Terrain Engine. I have some questions regarding its ...
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125 views

beginContact triggered more than once on some objects

Short version: It looks like beginContact is detecting continuous collisions. I'd like to avoid that. Long version : I use Box2Dweb to write a 2D platformer. It's my first game using this lib, and, ...
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1answer
97 views

Cocos2D: Box2D body that is movable by one type of object but not another

I'm in the process of creating a simple platform game using Cocos2D 2.0 and Box2D. I'm trying to create a kind of crate object that cannot be moved by the player, but that can be moved by an elephant ...
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1answer
266 views

Box2D: Asteroids-Like Spaceship Physics

I'm new to Box2D (JavaScript) (and the world of physics/mathematics) so I'm having a hard time working out the methods I need to use to make a spaceship act like it does in the classic arcade game ...
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1answer
296 views

Box2d contant speed before and after collision

I want to make my body fly at constant speed, how to make it fly at constant speed before and after collision? I set restitution of my body to 1.0 but after some direct and powerful collisions my ...
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1answer
263 views

Box2D Joints in entity components system

I search a way to have Box2D joints in an entity component system, here is what i found : 1) Having the joints in Box2D/Body component as parameters, we have a joint array with an ID by joint and ...
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133 views

How to make the Angry Birds “shot arch” dotted line? [duplicate]

I am making a game that includes 2D projectile flight paths like that of Angry Birds. Angry Birds employs the notion that a previous shot is shown with a dotted line "arch" showing the player where ...
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1answer
278 views

How to implement server side physics?

I am working on 2-player 2d sidescroller. How should I implement the physics on the server? Use one world for every game or use a big world in which I add every 2 player that start a game? I have ...
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1answer
132 views

Using Box2D for range detection?

I have two entities. One has a sword, one has a bow and arrow. When the bow entity is 100 units away, he needs to begin attacking. Likewise, when the sword entity is 10 units away, he needs to begin ...
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90 views

Language & framework for fast prototyping Box2d problems [closed]

I am often in need of a fast prototype box2d scene where I can play with parameters. I work with AndEngine on Android which doesn't suit me for prototyping. It's good for the final game, but ...
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1answer
191 views

How do I change gravity of box2d world after world is created?

I want to modify the world of box2d after creating it, namely to change the gravity vector. Is there a way to do this?
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2answers
96 views

AndEngine: edit elasticity on action

I'm making a game for Android with AndEngine. It's going quite well, but now I'm stuck on something. My main character has a elasticity set in its fixturedef so it bounces around throughout the ...
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1answer
566 views

Problem Implementing Texture on Libgdx Mesh of Randomized Terrain

I'm having problems understanding how to apply a texture to a non-rectangular object. The following code creates textures such as this: from the debug renderer I think I've got the physical shape ...
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670 views

Generating a physics body for 2D Worms-like Terrain

I wrote a processing sketch that generates hills for a scorched earth clone, like this: I'm trying to figure out how to make this a physics object in libgdx, but I'm having problems figuring out ...
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179 views

Moving a Box2D object in the direction it is facing using applyForce [duplicate]

I'm trying to apply force to a polygon physics object to move it. Whilst I can get it to move upwards easily enough, I'm trying to get it to move in the direction in which it is pointing. Here's my ...
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63 views

Ring and Pole - Box2d

How I can make a b2Body in box2d so that it could form a ring which does not collide from the center just like a ring. like when we flick the object and there's another body (like pole), the pole can ...
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643 views

How to simulate feather fall in box2d?

I am working with AndEngine with Box2d extension, but general answer or a concept idea will be appreciated too. I have feather-like objects in a 2D side view world that I want to be part of the ...
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2answers
304 views

2.5d with box2d - approaches from the top and bottom

So, I'm using box2d for my 2.5d game (think double dragon, tmnt arcade, castle crashers) where you can move around on the z-axis (faked as y-axis movement). Basically, I have box2d only doing ...
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84 views

360 degree gravity game mechanic like “They Need To Be Fed” game

I am a fan of "They Need To Be Fed" game and I want to understand the game mechanic at a deeper level. What are some good resources for the basic Box2d (or similar) physics behind the 360 degree ...
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309 views

Hill-jumping game mechanic like Tiny Wings

I'm a huge Tiny Wings fan and I'd like to understand the game mechanic at a deeper level. What are some good resources for the basic Box2d (or similar) physics behind the hill-jumping game mechanic? ...
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2answers
168 views

Client-side physics simulation

I am trying to create a very simple client-server based physics game, using box2d library. A simple football game. Obviously, the server runs only the box2d world. My question is: is it correct to ...
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1answer
248 views

Separation algorithm in flock simulation?

I'm using box2d (the c++ one). I found a method for an arriving behavior (on http://www.red3d.com/cwr/steer/gdc99/ ), which works well, problem is, the bodies are bumping into each other and it ...
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Weld Joint Box2d not run

i have two object like this : b2WeldJointDef weldJoint; //frist body bodyDefXich.type = b2_dynamicBody; bodyDefXich.position.Set(3, 2); b2FixtureDef fixtureDef; b2PolygonShape ...
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100 views

Catching an object from sky in Cocos2d and Box2d world

My world has a gravity of -9.8 and there are KDynamicBodyType bodies falling from the sky. At the bottom there is a PhysicsSprite with KinematicBodyType. I want the PhysicsSprite to be able to catch ...
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1answer
212 views

Is there a “box2d without physics” lib (only for collision detection)?

Box2d Collision detection algorithms are probably the best ones out there. Unfortunately, they are bundled together with a realistic physics engine that I don't need. Is there an open source project ...
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152 views

Bodies do not stay sticked together by joint in retina display

I'm rehearsing on Box2D revolute joints. Everything's going pretty well except for one thing. For some reason bodies joined together with revolute joints do not stay sticked, they start getting apart ...
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1answer
248 views

How do I copy box2d data from one body to another?

I want to copy all Box2D-related data (position, velocity, rotation, impulse, ...) from one body to another. This is what I've got working (with box2djsweb): var t = body.GetTransform(); ...
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380 views

Why might a body suddenly stop while moving on continue platform?

I have a 32x32 sprite and I make some to be platform like this for (int i = 0; i < 15; i++) { attachChild(new Ground(32 * i, 200, regPlatform, vertexBufferObjectManager, physicsWorld)); } ...
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539 views

Is using Box2D for simulating gravity “in space” a good idea? [duplicate]

I'm attempting to write a simulation of a solar system of planets in 2D space that are attracted to each other through Newton's law of universal gravitation. I know that it is possible to simulate ...
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242 views

Slow Rope Joint Simulation

I am right now developing game similar to Cut The Rope. But I have some problem in developing this game. I have successfully created rope and attached multiple rope with candy. Below I represent ...
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Box2D, OpenGL, resolution and matrix setup [closed]

Okay, my internal units are going to be meters, ranging between 0.1 and 10 meters for size. First of all, my mind is all wrapped up in a knot trying to understand how to handle my game with multiple ...
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1answer
165 views

Box2D OpenGL debug renderer convert box2d coordinates to world space

I made an OpenGL 3.x renderer for Box2D's debug draw (b2Draw base class). Unfortunately I've tried for a while now to convert the box2D units, which are meters to my internal units which are pixels. I ...
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2answers
351 views

Making the player walk on walls in box2d

I'm making a game in stencil where players walk form left to right along randomly generated walls. I cant use waypoints, since the walls' shapes and positions are unpredictable. Here's a descriptive ...
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1answer
140 views

Is it bad practice to set the velocity of an object every loop?

Say I have a simple game with a gameLoop function that gets called every 50 milliseconds or something similar, and I have a box2d object. Is it bad practice/too CPU intensive to use SetLinearVelocity ...
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1answer
410 views

AndEngine; Box2D - high speed body overlapping, prismatic joints

I'm trying to make good suspension for my car game, but I'm getting nervous of some problems with it. At the beginning, I've tried to make it out of one prismatic joint/revolute joint per one wheel ...
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1answer
437 views

Libgdx import bin/xml/json from physics editor

I'm using Libgdx. I did a simple json file in Physics Body Editor and I don't have any idea how could I import it into my physic world in libgdx. Any idea will be appreciated. P.S: Sorry if there ...
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3answers
317 views

Libgdx body passing through block then fall on it

I'm using libgdx and its physic engine Box2d. My question is : how could I make my box2d body go through a block , ignore the first collison than make the block active so the ball can fall onto it. A ...
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1answer
570 views

Mario like jumping and landing in box2d, help

I've been trying to get Mario type jumping/landing in a Box2d game and it's been giving me some trouble. Results: Player loses velocity on landing Desired Results: When player lands it will continue ...
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1answer
350 views

Rotate Box Sprite With Circle Body

I want to rotate my rectangular sprite with circle body. The problem is the body doest not attached to the centre of the sprite. This was the default behaviour of the body and sprite. But I want that ...
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270 views

Why won't my Box2d bodies collide? [closed]

I'm doing something wrong when trying to get bodies to collide using jBox2d & Slick2d. Here is have just my basic init, update, and render methods. Render and update seem to work fine for drawing ...