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

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shiffting the camera and set a new scene when using box2d

this is my jsfiddle : http://jsfiddle.net/V8eKp/1/show var Scene = { _Collection: [], addElements: function (Coll) { for (i = 0; i < Coll.length; i++) { ...
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Box2D—set Position of multiple bodies

I have a character composed of five bodies which are tied together by a lot of joints. On of them is the overall chassis, to which all forces and impulses are applied to move the whole Character. All ...
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30 views

2D Range Searching

I have a 2D jump'n'run browser game based on SVG, whereby the entire game-world is included in one huge svg (28px * 16000px, ~3.5MB). Unfortunately is rendering kind of too complex and the browsers ...
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89 views

Scrolling with SDL2 & Box2d - My Camera isn't keeping up with my player

I'm trying to get a game on the google play store before I'm 40 (long held dream to publish a game since the days of the speccy), I have just over a month to go so it's not looking good! Foolishly I ...
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55 views

Preventing rapid inversions of boolean on Collision detection

I know this is both a strange question and a stupid question. But this is an issue I have dealt with in every single game I've made, and I have yet but to find a solution. I can't be the only one ...
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38 views

Box2D: Adjusting character position for side-scrolling

In my side-scroller I would like to give the illusion of the character walking forward while his sprite is actually being held in place. If he walks near the edge of the screen, I would like to adjust ...
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413 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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112 views

Rotating an object about a point (2D) using box2d

i just started developing using box2d on flixel and i realise the pivot point of the rotation of an object in box2d is set to the center of an object. i had read on forums and i found out that ...
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23 views

setChaseEntity freezes or jitters the AnimatedSprite

I'm trying to implement setChaseEntity method in a physics based app. I wrote the below code which has an animated sprite ans as the player. The player is movable and it can jump. When i try to focus ...
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1answer
41 views

Player doesn't jumps in Box2D implementation [closed]

Well, i'm trying to learn andEngine. I was able to successfully implement the move functionality for the player. Now, i'm trying to make the player jump using Box2D. I referred few online tutorials to ...
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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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53 views

Is there any reasons to make sprites and bodies line up?

So in LibGDX the Sprite objects position is where it's 0,0 mark is in the word. In Box2D a a bodies position is in it's center. So to line these up when you update the sprites position with the ...
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17 views

GWT problem with Box2D WheelJoint

I am using the below libgdx java code for a wheel joint and rear axle using Box2D. This works fine for android, Desktop, but when I attempt to run through GWT I get the following error. at ...
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1answer
578 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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box2dweb issue in DestroyJoint function

my jsfiddle : http://jsfiddle.net/H8e9m/9/ as you can see when the ball reach the pendulum end and collide with it by a revolute joint, the problem occurred when trying to make the ball release the ...
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1answer
26 views

How do I dynamically set a WheelJoint's anchor points?

I've created a car in RUBE and imported it into my game. The game has a tuning menu, allowing the ride height of the car to be adjusted with a slider. I can't work out how to change the position of ...
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1answer
118 views

How do I prevent other dynamic bodies from affecting the player's velocity with Box2D?

I'm working on my player object for my game. PhysicsBodyDef def; def.fixedRotation = true; def.density = 1.0f; def.position = Vec2(200.0f, 200.0f); def.isDynamic = true; def.size = ...
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446 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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Box2D—Dropshadow

I am about to create a Jump'n'run game using Box2D for the physics. I am asked to add a Dropshadow to the main Character, but as I noticed this could become quite complicated. Basically the Light ...
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2answers
37 views

(LibGDX) Changing Origin of Box2D World relative to TiledMap (or Vice Versa)

I'm playing around with Box2D and TiledMaps and I've come across this minor annoyance. As you can see, both Box2D and TiledMap render at the center of the screen. This forces me to compensate by ...
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1answer
3k views

LibGDX Box2D Body and Sprite AND DebugRenderer out of sync

I am having a couple issues with Box2D bodies. I have a GameObject holding a Sprite and Body. I use a ShapeRenderer to draw an outline of the Body's and Sprite's bounding boxes. I also added a ...
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32 views

SVG—Adding fire to the roket

as you might expect, I have got a game in development, including a main character—fortunately… This character is on the one hand represented by a bunch of Box2D bodies and on the other hand, ...
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195 views

Communication between Box2D and libGDX Stage (Scene2D) running in separate threads

I'm making a physics based 2D game using libGDX and Box2D. I want to move the execution of the simulation out of render thread. I use immutable messages and the BlockingQueue to pass the information ...
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Trying to make a mouseJoint with Box2D on Cocos2D-X

I'm trying to obtain this result: http://appcodingeasy.com/Gideros-Mobile/Dragging-Box2d-object-in-Gideros-Mobile (there's a video - YouTube). But I'm missing something, because if I follow the code ...
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42 views

How to find correct offset to adjust sprite to the position of box2D body after rotation

I am trying to implement phsyics with the as3 box2d port. I currently have a b2body for each of some certain sprites in my game and I am able to update the sprite's positions correctly from the ...
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1answer
86 views

Movement and rotation of bodies in top down game

We are developing a 2D top down game with libgdx using the included box2d as physics engine. We don't want our bodies to accelerate but to instantly move with the wanted velocity. The bodies are ...
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36 views

Box2D—how make character tilt

I have got a floating character, which should be a robot like thing, floating over the ground, whereby I am using the »hovercar« effect described here. Zhe Image below outlines the basic setup of the ...
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1answer
220 views

Box2D Static-Dynamic body joint eliminates collisions

I have a static body A, and a dynamic body B, and a dynamic body C. A is filtered to not collide with anything, B and C collide with each other. I wish to create a joint between B and A. When I ...
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61 views

Body height width is different from sprite height width in box2d libgdx

I have a problem with box2d in libgdx. I was makin 5 kinematic moving platform on which a dynamic body player can jump. Height of plateform is varying from 20 to 110 pixel which I am passing to body ...
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1answer
56 views

How to get width and height from a body in box2d?

I am working on a game in Libgdx framework. I have to get width and height from a body in box2d. is their any way to get width an d height from a body in box2d??
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26 views

Box2dLights rendering in bigger scale

So basically my box2dLights are rendering in wreid places. The circle in center is my player and as you can see lamp which should be aligned to player is in the right-top corner. my code: package ...
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74 views

How can I load an SVG file and create a shape and collision data from it?

I'm looking to write a game in C++ with vector-styled graphics. For this, I will need to turn an SVG shape into a Box2D body and a polygon for rendering in SFML. I don't need the full capabilities of ...
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26 views

Apply impulse to ball to a fixed height Jbox2D android

I have to hit a ball to a fixed height repeatedly as shown in the following image. This game is similar to 1983 Hitit The difference is the hitting y axis will be variable. I wanted to hit the ...
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200 views

How can I simulate a floating character in Box2D?

I am creating a jump'n'run game using the Box2D physics engine. The main character should be a robot like creature without legs, floating over the ground powered by a jet engine. The motion should ...
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1answer
79 views

Dynamic Hills like Contre Jour in Cocos2d

I'm interested in maps/environments which are flexible and change at runtime, such as those in Contre Jour. I have looked for a long time to find out how to make this effect, but I couldn't find an ...
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1answer
35 views

Why can't I swap fixtures on collision in Box2D?

I'm trying to swap the fixtures associated with a body after colliding with a specific obstacle. I can listen to the collision event by extending b2ContactListener. I tested it with a trace and it's ...
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65 views

How can I smoothly rotate a joint to an angle? [duplicate]

I would like to set the speed of my Box2D revolute joint on every update such that it rotates to a desired angle and stops. It should ramp down as its angle approaches the desired angle. My first ...
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31 views

Map in Scene2d/LigGdx

I'm a little lost for my game. For the moment I've a car, who work, but now I want to create a map (like hill Climb Racing for example, not necesserly randomly generated). I don't know how to do ...
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1answer
252 views

Maintaining velocity of free fall body using Box2D in libGDX

I want to maintain the speed of a free-falling Box2D body using LibGDX. I'd like the vertical velocity increase with the level. I've applied a linear impulse and velocity actually increases like this: ...
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829 views

Why do restitution values less than one still cause infinite bouncing in Box2D?

I'm currently trying to implement basketball bouncing into my game using Box2d (jBox2d technically), but I'm a bit confused about restitution. While trying to create the ball in the testbed first, ...
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69 views

How do physics engines like Box2D detect and respond to collisions between arbitrary polygons?

I've always wondered how collision detection like this was achieved, and I've always wondered what the response would be. Do they perform line-line intersection tests for each line making up the two ...
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66 views

LibGDX - Box2D: Realistic Light and Layers

I'm having some problems with my current game. Short description: It's a 2D game where you have to avoid the lights or you lose HP. My problem is the following one: Here is the rendering process: ...
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1answer
65 views

Box2d stopping the movement of an object

I am in the process of making a game and I need an object to move only when the buttons are pressed. I have a method that begins the movement, and so far I am ending the movement of an object by ...
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59 views

Simulating a single water droplet in Box2d

This is for a class project. The main character in the game is an oil droplet and we're trying to simulate it using Box2D. One of the levels in the game is where the oil droplet is in contact with ...
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Prismatic Joint causes a crash-Box2D(cocos2d)

tried to set up a prismatic joint, but I get this error upon run time: Assertion failed: (IsLocked() == false), function CreateBody, file ...
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1k views

What causes Box2D revolute joints to separate?

I have created a rag doll using dynamic bodies (rectangles) and simple revolute joints (with lower and upper angles). When my rag doll hits the ground (which is a static body) the bodies seem to ...
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1answer
452 views

How do I make a curved surface out of rectangular blocks?

For a Peggle-like game, I want to make blocks that follow a curve, like this: The blocks would then disappear as the ball hits them. I managed to draw some horizontally, but I'm having trouble ...
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3answers
73 views

Box2dWeb: setting velocity of bodies using events

I would like to move a kinematic box by pressing the down arrow. As is noted by the console logs, the keydown actually does change the box's velocity... but for reasons beyond my grasp it still ...
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26 views

Andengine Box2D Physics “disappearing”?

I have problems with my PhysicsWorld in Andengine GLES20. Sometimes when i first load my app and level there is no velocity added to my bodies. they also rotate slower as it seems. This also happens ...
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92 views

Collision function calls before colliding

My Box2D contact listener class is calling post solve and beginning the contact function before colliding? This is causing my object to bounce back before hitting the ground. What could be causing ...