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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Box2D Issues determining the side of collision

I'm trying to determine which side of my object a collision is happening. In all of my searching, I have found 2 different proposed solutions, but each one has a major issue. I'm hoping that someone ...
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2answers
73 views

Pole vault with Box2D?

I would like to replicate the behavior of a flexible pole as used for pole vault. Can somebody give me some inspiration how to simulate that with Box2D? Would I cannot multiple objects with flexible ...
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2answers
250 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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2answers
69 views

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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2answers
279 views

Libgdx box2d crashing

im making a game in libgdx which i having a bunch of circle bodies floating around in space and when the player's body crashes into another body, that body deletes and creates two smaller bodies ...
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1answer
299 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 ...
3
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1answer
490 views

Change the shape of body dynamically

I have a problem where i have a ballon which i need to continuously inflate and defalte in update method, I have tried to used setScaleCenter but it is not giving desired result. Below is a code i am ...
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1answer
35 views

Should I initialize a Box2D World per Level?

I'm using a LevelManager to load Tiled maps in my libGDX game, which stores: Static: final Size of map in Tiles final Size of map in Pixels final Size of an individual tile TiledMap ACTIVE_MAP ...
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1answer
114 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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1answer
196 views

LibGDX Box2D TileGame Efficiency

I am trying to implement Box2D into my top down tile game in LibGDX. Each world consists of a set of chunks, and each chunk is 16 tiles wide/long. The maximum/minimum chunks loaded at one time is 9 (a ...
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1answer
31 views

Running and Jumping using Box2d and libgdx

.this is my first trial on making a 2d game and currently struglling how to run and jump smoothly. My problem is when the player keep pressing on left or right botton then jump. the player won't jump, ...
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1answer
48 views

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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1answer
108 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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1answer
121 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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1answer
89 views

Rotating towards a point in Box2D

I'm using Box2d as my physics engine and I'm trying to solve what would normally be a simple problem but what has become a nightmare for me and preventing me from finishing my app. (6 months work) ...
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1answer
335 views

Lighting shadow casting sprites with box2Dlights

I currently have something like this using box2Dlights Ideally, I would like objects casting shadows to be lit, so the object is lit but there is still a shadow cast around it. Right now the object ...
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1answer
407 views

Changing Box2D Body from Kinematic to Dynamic after contact

What is the correct way to change a Kinematic body into a dynamic body? context - I have a dynamic body as a projectile which has to be fired at a kinematic body (it is kinematic because i am ...
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1answer
474 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
395 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
1k views

Drawing Shape in DebugView (Farseer)

As the title says, I need to draw a shape/polygon in Farseer using debugview. I have this piece of code which converts a Texture to polygon: //load texture that will represent the tray ...
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1answer
84 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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1answer
139 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
78 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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1answer
156 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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1answer
305 views

Move Box2D body towards mouse click

In a top down game using Box2D, I would like the player's Box2D body to rotate towards the mouse click, and then move to a point on mouse click (move, not teleport). I have worked out the rotation ...
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1answer
110 views

box2d ChainShape into curved line

i need to draw a curved line , i searched the internet and found nothing , maybe someone with knowlegde on the subject can help me with a link , i used chain shape and did this , and i don't know ...
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1answer
555 views

How to render a vertex buffer in DirectX11 C++ (specifically with box2d's b2Draw)

I have all the DirectX11 devices etc setup and working with DirectXTK's SpriteBatch and currently attempting to implement a b2Draw class to draw my box2d physics worlds. I have little idea on how to ...
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1answer
75 views

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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1answer
79 views

Relative movement in Box2D (keep object from falling off planet)

I'm creating a game with planets orbiting around a sun, like this: The brown square is the earth, rotating around its center and around the sun. The yellow square is the sun, which doesn't move. Now ...
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1answer
58 views

What's the difference between Box2D and tweening?

It seems like Box2D can be used to move sprites across the screen, so how does this differ from tweening? Is it that Box2D is for physical collision detections and tweening is just animations?
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1answer
152 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 ...
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1answer
529 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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1answer
1k views

Create Box2D and engine polygon Box2D body without sprite

Hey I have created my body using following code: (please read full description) Body polyBody; final BodyDef mBodyDef = new BodyDef(); mBodyDef.type = BodyDef.BodyType.DynamicBody; ...
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Shifting the camera and setting a new scene when using Box2D

My jsFiddle: // START -- MOVE CAMERA var p = new b2Vec2(); p = (ball.body.GetWorldCenter().x) * physics.scale; pos.push(p); var length = pos.length; var s = (pos[length - 1] - pos[length - 2]); //in ...
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63 views

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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146 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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84 views

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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63 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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872 views

Box2D Soft Body Wheel in Unity3D

I was watching this video made with IForce2D, its about creating soft bodied wheels in box2D. http://www.youtube.com/watch?v=F-aDMZUVw0c I wanted help in being able to increase the Radius of the ...
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386 views

box2d's ApplyForce works wrong after cocos2d-x's replaceScene

i'm practicing making a breakout game, using cocos2d-x 3.x and box2d, referencing here. i create a ball in the scene's init function and apply force. when ball hits bottom wall, if i touch screen ...