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

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C++ SFML and Box2D: Move world or move player?

I'm currently making a top-down shooter game and it's my first time developing with SFML. I came across and issue and I want to know if there is a better way to solve it. I need to get the "camera" ...
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generate box2d bodies from isometric tiled map

I followed the tutorial here to generate box2d bodies from a tiled map and that worked fine.... for orthogonal tiled maps. Unfortunately isometric maps use their own coordinate system where (0, 0) is ...
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LOVE Physics - Joint Stretching

After asking a similar question yesterday I've come across another problem with using joints in box2D / LOVE and trying to create a weighted chain. Everything is set up as follows, I've tried to ...
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LOVE Physics - Breaking Joint Chains (LUA / Box2D)

Wasn't sure whether to post here or on SO so please move if needed. I've been having a look into the box2D physics API provided by LOVE to try and create a swinging flail or weighted rope but I'm ...
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How to make sure that when two bodies collide, there is only one collision detection on box2d?

I'm using LibGDX with box2d, and when to bodies collide collision is detected multiple times. here's the code `public void preSolve(Contact contact, Manifold oldManifold) { Body a = ...
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Move a box2d body towards mouse [closed]

I'm using LibGdx's Box2D in Java. I'm trying to apply a force to the body that would send it towards the mouse. The problem is, I'm having trouble figuring out a way to send it directly to the mouse ...
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25 views

Which Box2D-like physics engine parameters need pixel conversion?

The official guide does not have any useful details on the matter: http://www.box2d.org/manual.html Position is an obvious one. What about velocity? Density? Anything else? Update: the context is ...
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63 views

Box2d Body to follow mouse movement

I am trying a box2d body to rotate following the mouse. Here's an image to clarify what I mean. The red and blue circles are current point of the mouse and the body (of corresponding color) ...
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37 views

Libgdx Scene2d and Box2d light

Currently I am using scene2d and I want to implement shadows using Box2d light. I want shadows under characters but when I draw something after render() , it draws nothing. For example, in draw() ...
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48 views

Box2D No Gravity when moving against wall

I use Box2D in my current project and I have a problem with the gravity.. You can see my problem here: https://www.youtube.com/watch?v=2_kv9LkKwN4&feature=youtu.be when i jump normal everything ...
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78 views

Creating a Melee Weapon in Box2D (libGDX)

I am struggling with how to implement a melee weapon that can swing when a key is pressed. I am imagining two different attacks (stab and swing) I have tried creating two fixtures (character + ...
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40 views

Use libgdx box2d for dynamically generated top down map

So, I've already found some information on how to use box2d and tiledmap together. Since I want to generate my top down map (100 by 100 tiles), I thought about only using box2d. The tiles would be ...
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LibGDX , Box2D body Mass Center

I am creating complex bodies using this editor. But the mass center of the body is not in the right place , when I apply force to it it begins rotating . So I am confused why is the masscenter in the ...
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18 views

Adapting qml-box2d to work with QGraphicsScene: transform origin is incorrect

I'm taking the convenient QObject wrappers from the Box2D QML Plugin and using them with a QGraphicsScene-based game. My motivation is to save time writing them myself, as I need to expose stuff to ...
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1answer
61 views

Libgdx using Box2d with TiledMap to create collision detection

I'm fairly new to Libgdx and have some good basic knowledge on Java. Right now I am stuck on how to add collision to my TiledMap, I am using the Mapeditor to create the tilemap. I read so many ...
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21 views

Sizing a Box2D ground object

I am developing a platformer game using SDL2 for graphics and Box2D for physics. I am currently designing my levels and would like to know if it is better to make the static part of each level (ie: ...
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23 views

LibGDX, Box2D , Destroy body into parts

I am developing a game using libGDX game engine and box2d physics engine. There are asteroids in my game, I want to destroy their bodies randomly and fill with texture. How can I do it?
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70 views

Why does physics interpolation give me periodic jumps/flickers?

I have seen this question but it didn't solve the problem. I have followed the same steps as in this article. What I notice in my Android game is that my interpolation alpha (or fraction or ...
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Box2d joints still attached after Explosion simulation

I ported simple Box2d Explosion simulation the function is called once when there is some event with the "Truck Car" the problem is that the Explosion working fine but it looks like when the explosion ...
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68 views

What are the steps for creating level in Libgdx with Box2d?

I have been trying to learn game programming for a week, although I have a good knowledge of programming. I don't understand some steps of game design. I'm recently working to clone the iSlash ...
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116 views

Good collision resolving mechanism

In my game i have plenty of objects that can collide. Literally, most of them can collide with each other.The problem I'm facing is that i can't come up with some good collision resolving way. How can ...
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1answer
54 views

Calculating density of an object

I'm using Box2D for physics in my game, and one of the things it needs to know when creating a shape for a physics body is the shape's density. I had no idea what value I should specify, so I went to ...
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69 views

How to convert pixels to meters in Box2d with Cocos2d-x 3.5?

I am using Cocos2d-x 3.5. I created a simple game with edge bodies and one circular body to test box2d. Physics wasn't working well, so i thought i should convert pixels to meters and use that meters ...
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Body lost a velocity component when hitting a wall

I am creating a Breakout game using Box2D (of LibGdx if anyone interest). Everything works well until when the ball hits the wall when moving with a very small angle. Please look at the image for ...
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1answer
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box2d not centered in sprite [duplicate]

I am trying to create a bounding box for my sprite using box2d, but the box is being created at the wrong spot. I followed a tutorial on the wiki using this code BodyDef bodyDef1 = new BodyDef(); ...
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35 views

b2DistanceJoint with frequency equal to 0 vs b2WeldJoint

What is the difference of b2WeldJoint and b2DistanceJoint? They both have frequency and also when you put frequency of Distance Joint to 0 it acts like Weld Joint. It seams that you can create ...
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Setting Up the PTM_Ratio for Different Devices

I want to set the the physics for my Game and I have used Box2d for the Physics Simulation. And to do that I have set the PTM_Ratio to 32.0f.But When I run my Game on Different Android or iOS Devices ...
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1answer
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In Box2D, how do I create an infinitely oscillating spring?

How do I create an ideal spring that can oscillate indefinitely using Box2D? A b2DistanceJoint works almost perfectly, but it eventually slows to a stop, even with damping set to 0. I think it is ...
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1answer
43 views

Checking if Body is surrounded by other Bodies

I'm trying to make a game like Rampart as practice. I have gotten to the point where I want to check if the castle is surrounded by walls and decide whether to fill in the area and continue the game, ...
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Box2d c++ can't see b2PolygonShape

i try to follow this tutorial and convert it to c++ http://www.emanueleferonato.com/2009/04/06/two-ways-to-make-box2d-cars/ the second part of the tutorial Now im facing very strange Behaviorno ...
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57 views

Calculate the rest length of a box2d distance joint

Given the length of a distance joint along with its frequency and the mass of the bodies involved, is it possible to determine the final rest length? I'm only interested in the vertical axis if that ...
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Using Box2D in LibGDX, is there a reason a fixture set to be a sensor would only -sometimes- detect a collision?

I am working on a 2D game in LibGDX. Currently, I am testing interactions between a player's weapon and enemies - in particular, a sword and an enemy monster. The player has a hurtbox and the sword ...
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Can't perform normal jump after applying revolute joint

I have encountered the following problem: I have two PolygonShapes which I had connected with a RevoluteJoint. The first body is called square the second is called weapon, before connecting the two ...
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1answer
123 views

My Raycast will not detect collisions in my Unity 2D project. What am I doing wrong?

I appreciate any help you can offer me. I created a script for a character controller that casts two rays below the player's gameobject. The rays extend infinitely and should collide with another ...
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1answer
102 views

LibGDX Box2D Lights - Illuminate background

I have a box2D world made of tiles. I use a custom DirectionalLight for light up the scene from above (It shines through transparent blocks [eg.: the water] more deeply). The problem is (as expected), ...
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Box2D replace Fixture not working as expected

I am using box2D to develop a simple game, and I am using the Physics body editor by Aurelien Ribon to load the fixtures into bodies. I have written the following method which should scale my ...
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Box2d :What is the best approach to build static Box2d smooth curve line [duplicate]

i want to know what is the best approach to simulate smooth curved line as static body it will be like path for car to drive . something like this : http://www.freeriderhd.com/ how does its box2d ...
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97 views

Preferred way to integrate box2d with SFML

I'm trying to integrate Box2D with sfml. My current solution is to have overloaded functions creating sfml shapes from box2d fixtureDef shapes. I store created sfml shapes under the name 'visual' in a ...
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1answer
182 views

Box2D Lights - Simulate water

I have a libGDX project, in which I have a Box2D world, which is currently filled with some boxes as a terrain. I also added a DirectionalLight to the scene for simulating the Sun. I almost have the ...
2
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1answer
63 views

How to restrict jumping to a single jump?

I'm making a VolleyBall game in HTML5 with PandaJs GameEngine and plugin is used physics and Box2D. The problem is that players can jump, but they can jump over the net with multiple jumps. I have ...
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1answer
64 views

Using Box2D for soccer physics

I've learned quite a bit of Box2D and I've succeeded basic stuff concluding ball physics. I want to implement 'opposing forces', as the character kicks the ball with a certain strength, with the leg ...
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1answer
662 views

Libgdx Box2D and Screen Viewport Scaling

I am currently having problems getting an easy to manage system of scaling my units for use with box2D. Normally I would create virtual units to go along with me viewport and camera but since I am ...
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22 views

How will i know if the Body is facing a the target angle [duplicate]

I want to know if the body of the car is facing the line on the picture
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How to handle transparent pixels in a spritesheet

I am trying to correctly handle transparent pixels. I have a spritesheet that gave me the following: The green body is the ground physics body and the gray body around the sprite is the sprite's ...
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1answer
117 views

Implimenting BADLAND like Body Movement in Box2d

I am trying to make a body (character in my game) move and behave in the same way as the character in the BADLAND Game with regards to rotation. The character does not have fixed rotation and behaves ...
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39 views

Box2D: Making it Determinsitic?

From articles on the web, I found that floating point math generally has accuracy of at least 6 digits. With this in mind, is it possible to make Box2D which uses floats fully deterministic through ...
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How to trim a sprite?

I have a spritesheet: var spriteSheet = new createjs.SpriteSheet({ // ... frames: { width:520, height:600, regX: 260, regY:300 } // ... }); I am computing it's physics body as follows: ...
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Dynamic body in Box2D with fixed position

I need to fix the dynamic body position so that it would not rotate and would not move even if there are other forces, collisions and so on. Let me first explain why I need this. I have a dynamic ...
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133 views

libgdx - Box2d debug draw not correct

I have a problem where the bodies in my debug draw does not draw correctly, take a look: As you can see, there is some space between the dynamic body and the ground. I have checked the contact ...
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Tiled PolygonObjects rendering wrong in libgdx

this is how I render the polygons in Tiled this is how they get rendered in libgdx. Notice the top part of the triangles is straight instead of being hollow. here is the code I use to convert the ...