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

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Stopping on a slope in Box2d

I am creating a simple platformer using Box2d. I've implemented a variant of the technique described here. To make the player character move more 'platformer-like' I want him to stop on (shallow) ...
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1answer
186 views

How to handle sprite speed when objects move using Box2d?

I have a basic platformer using Box2d that works great. However, I now want to stop using my default square, and implement some running and jumping animations. How can I ensure that: When running, ...
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4answers
3k views

Box 2d Level Editor for AndEngine [closed]

I am getting started with Box2d in AndEngine. I need to know if there is any level editor to be used with box2d and gives output capatable with AndEngine. Is there any tool which can help me building ...
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1answer
629 views

How to make a character in a Box2D world jump faster?

I have a question about using Box2D to simulate a physics-platformer. I manage to make the character move to the right and left, and jumping as well. However, jumping seems extremely slow when ...
2
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1answer
302 views

Best way to allow a user to Control Body in Box2D

I am working on a simple game and I am deciding how I should let users interact with the world. I really have 2 options, 1.) When the user moves an object I apply a force to the body 2.) With each ...
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2answers
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How do I get the touch event on a body in Box2d(Java)

I have various bodies rotated at some angle with the help of Box2d in libGDX. What I want is to destroy the body when I click on it, but the problem is that I am not able to get the area definition of ...
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2answers
2k views

Applying Forces to Box2D Bodies

In full disclosure, I am VERY new to box2D let alone the Java version of it. I have a box (here of type Hero) that I am trying to move. I did this by trying to apply a force as follows... private ...
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3answers
299 views

What could cause a sudden stop in Box2D?

I'm using Box2d for a game, and I have a bug that's driving me nuts. I've simplified the situation down to a square player sliding back and forth frictionlessly on top of a floor composed of a series ...
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1answer
287 views

Letting the user draw a Polygon Body and Image

In my game, I want to provide the user with a drawing feature. By free hand drawing, the user creates a polygon shape. Then, in my game implementation, I have to create a body for the found vertices ...
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2answers
1k views

Error in destroying object in Box2D/LibGDX

I'm trying to delete an object when a collision happens. I have put the following code in the render method of the object so it would be outside of the physics calculations. public void ...
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1answer
118 views

Questions for QueryAABB

I'm currently having trouble getting my head around QueryAABB, and hope to find some answers here. The LowerBound of an AABB the upper-left corner (and vice versa). Why is that and what idea is ...
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1answer
116 views

How to detect whether an Object came to sleep at a specific position?

I'm currently writing a small game with box2dweb and I need some direction for this: I'm throwing a Box and have to hit a specific place and trigger an event when the object that's been thrown isn't ...
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191 views

How to get the Exact Collision Point and ignore the collision (from 2 “ghost bodies”)

I have a very basic problem with Box2D. For a arenatype game where you can throw scriptable "missiles" at other players I decided to use Box2D for the collision detection between the players and the ...
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2answers
353 views

Single and Double Jump with single button.

I want to make Single Jump on Single Tap and Double Jump on Double Tap. My problem is that if I make double Tap on ground then it’s fine but if I make first Tap on ground and second Tap in Air then ...
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0answers
182 views

Flick Kick like game with box2d and flash as3 [closed]

What would be the best approach for creating a game like flick kick with box2d and AS3?. To make my self more clear, what i would like to do is to use the physics of box2d in the z-axis, i know that ...
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1answer
157 views

Basic Use of ApplyImpulse

I am trying to apply a force to a bunch of b2_dynamicBodys, but it seems to only work for a random number of items and then stops with an error. //create some items to move bodyDef.type = ...
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1answer
386 views

AndEngine Box2d game

I'm developing a 2d survival shooter using Box2d extension and I've got some questions: I have two AnalogOnScreenControls. Their listeners modify both sprites and bodies. I receive TouchEventPool ...
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1answer
556 views

Attach my sprite with Box2d [closed]

I'm coding Javascript(HTML5) with Box2D. And I want to ask how to attach Sprite with Box2D. This is function My sprite: function My_Sprite() { this.m_Image = new Image(); this.m_Position = ...
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1answer
2k views

Specifying force and angle in ApplyImpulse in box2d

I need to apply an impulse on a object with a particular force and at a particular angle in Box2d. If I am right the syntax would be the following: body.GetBody().ApplyImpulse(new ...
2
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1answer
743 views

What's the best way to handle slopes for a platfomer game using Box2D

I would like to know if there is any known solution for handling the player's movement on slopes using Box2D engine. I tried to do it using a circle as the player. Everything was fine until I tried ...
2
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1answer
726 views

Directional Lights

I'm working on a game idea (2D) that needs directional lights. Basically I want to add light sources that can be moved and the light rays interact with the other bodies on the scene. What I'm doing ...
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2answers
2k views

How to create an extensible rope in Box2D?

Let's say I'm trying to create a ninja lowering himself down a rope, or pulling himself back up, all whilst he might be swinging from side to side or hit by objects. Basically like ...
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1answer
269 views

Box2dWeb positioning relative to HTML5 Canvas

I'm new with HTML5 canvas and Box2DWeb and I'm trying to make an Asteroids game. So far I think I'm doing okay, but one thing I'm struggling to comprehend is how positioning works in relation to the ...
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1answer
98 views

Counting no.of bodies present in certain area in box2d?

I am stuck on it:how can i count or find the no.of bodies present in any area in as3?would be thankful if any guys help me out.....
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1answer
383 views

Wheel Joint Implementation in AndEngine

I am currently developing car game in AndEngine. In which I was using revolute joint for car wheel and chassis attachment. But my friend suggest me that use wheel joint for that purpose for better ...
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1answer
446 views

How do I make a rope from point A to B in Box2D?

I need to make a rope (preferably not elastic) from one point to the next in Box2D. If it helps, I'm trying to develop one of those 2D Spiderman games, like this: ...
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1answer
405 views

How to fly enemies like galaxian game enemies?

I am developing game like galaxian and using cocos2d with box2d .I don't have idea how to create enemies like galaxian game enemies and how do they fly over the screen. ...
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2answers
451 views

Detecting a ledge in Box2D [duplicate]

Possible Duplicate: Detect Open Space in Farseer How do I detect ledges? I'm making a 2D platformer with Box2D. The player needs to be able to grab onto a ledge and pull him/herself up. ...
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3answers
1k views

Rotate Body From Corner

I want to ask that how to rotate body from corner? movableBeam.getBeamBody().setTransform(movableBeam.getBeamBody().getPosition(), angle); The above line of code rotate the beam from center that I ...
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1answer
585 views

Box2D Bicycle Wheels Motor Problem - Flash 2.1a

I have made a bicycle with Box2D using several polygons for the frame at different angles connected using weld joints, and I have revolute joints on the wheels with a motor. I have made some basic ...
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1answer
664 views

RagDoll in AndEngine

I want to create a RagDoll body in andEngine which can run and jump over different jumpObjects. Can any one give a nice tutorial on how to create RagDoll body and how to move it, like jump and ...
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3answers
665 views

Semi Fixed-timestep ported to javascript

In Gaffer's "Fix Your Timestep!" article, the author explains how to free your physics' loop from the paint one. Here is the final code, written in C: double t = 0.0; const double dt = 0.01; double ...
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1answer
344 views

Implementing a wheeled character controller

I'm trying to implement Boxycraft's character controller in XNA (with Farseer), as Bryan Dysmas did (minus the jumping part, yet). My current implementation seems to sometimes glitch in between two ...
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1answer
332 views

box2d tween what am I missing

I have a Box2D project and I want to tween an kinematic body from position A, to position B. The tween function, got it from this blog: function easeInOut(t , b, c, d ){ if ( ( t /= d / 2 ) < ...
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1answer
390 views

GetContactList stops reporting collisions on welded bodies

I have some strange problem with my game which uses Box2D as physics engine and I'm out of ideas on what I can do to solve it. My game is a class assignment where I need to build a simple game where ...
2
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0answers
637 views

changing body type without change of center of mass

I have an box2d project with some bodies in it, which move around without any user interaction. But if the user selects one of the bodies, he should be able to move it around just like he wants to. ...
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2answers
633 views

How to move Objects smoothly like swimming arround

I have a Box2D project that is about to create a view where the user looks from the Sky onto Water. Or perhaps on a bathtub filled with water or something like this. The Object which holds the fluid ...
2
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1answer
731 views

Pathfinding and BSP with Box2D

I'm looking into implementing AI in my 2D side-scrolling platformer, and I'm looking into using algorithms such as A*. For many kinds of pathfinding, we need some sort of grid or systems of nodes or ...
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1answer
2k views

Andengine. Put bullet to pool, when it leaves screen

i'm creating a bullet with physics body. Bullet class (extends Sprite class) has die() method, which unregister physics connector, hide sprite and put it in pool public void die() { ...
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197 views

Box2d — get free space

I am developing a little Game with something like particles, where every particle is represented by a box2d Body. To insert new particles I need to find a place in the b2World where no bodies reside. ...
4
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1answer
2k views

making a box2d body move along a Bezier curve/ arc path

I have been trying to make a box2d body move along a Bezier curve/ arc path. Most of the posts I've seen recommend an approach of manipulating SetLinearVelocity and SetTransform to arrive at an ...
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2answers
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Can i add friction in air?

I have issue regarding speed in air. When i jump and move simultaneously that time speed of player increase.For jump i am using impuls and for movement i am using force.I want to slow speed when ...
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2answers
834 views

strange behavior in Box2D+LibGDX when applying impulse

I have been playing around with Box2D and LibGDX and have been using a sample code from DecisionTreeGames as the testing ground. Now I have a screen with four walls and a rectangle shape, lets call it ...
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1answer
762 views

Farseer Physics: Ways to create a Body?

I want to create something similar to this using farsser and Kinect: https://vimeo.com/33500649 This is my implementation until now: http://www.youtube.com/watch?v=GlIvJRhco4U I have the outline ...
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1answer
275 views

Creating multiple fixtures in one body

I want to create this type of fixture in one body. Here square and circle both are different fixtures but attach to one body. How do I do this?
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2answers
263 views

Confusing box2d forces

Hello Friends. This is my demo game screen-shoot. Here i am using three buttons. Right-bottom button is used for jump and left-bottom buttons used for move left and right. I have some questions 1) ...
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890 views

How to properly add texture to multi-fixture/shape b2Body

Hello to everyone this is my first poste here I hope that will be not fail start. At start I must say I make part 1 in Ray's Tutorial "How To Make A Game Like Fruit Ninja With Box2D and Cocos2D". But ...
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1answer
200 views

Sprite Body can not stop

Hey i have issue regarding jump sprite body. In my code i am using moveLeft and moveRight Button and when i am press moveRight Button using following code if (moveRight.active==YES) { ...
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1answer
487 views

moving box2d bodies in an arc or curved path

How can I make a b2Body move in a arc-like or curved path? I have heard about cocos2d Bezier curve function (ccBezier) but this is for moving cocos2d sprites. Or can it be modified to move box2d ...
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1answer
673 views

EXC_BAD_ACCESS error when box2d joint is destroyed

When I destroy the weldJoint in the update method (see below) I get an EXC_BAD_ACCESS error pointing to the line world->DestroyJoint(weldJoint); in the update method below: -(void) update: ...