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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How to make the interaction of sensors is in box2d? [on hold]

can not figure out how to make the interaction of the sensor platform has become active. something like this: BeginContact { if (sensorA && sensorB){ platform.getBody () ...
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84 views

Box2dMapObjectParser isometric map - bodies have wrong rotation and size

I'm using Box2dMapObjectParser to load Tiled objects layer onto my IsometricTiledMapRenderer'ed TiledMap. It works OK with a UnitScale of 1 but the position is wrong and some shapes have weird ...
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28 views

How to split a screen in half using LibGDX without scaling?

I am currently working on a racing game with libGDX and I need to split the screen in half for a two-players mode. (Player 1 in first half and Player 2 in second half). I already have Camera1 that ...
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33 views

Best way to create defence(withdraw) algorthim libgdx?

I have created user body and enemy body. Enemy body uses the steering behavior created by gdx AI. User body have it own control inputprocessor. World doesnt have gravity. Enemy body arrives the user ...
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35 views

Libgdx Sprite rotation around specific point

I made complex dynamic body that rotates around other body that is static. It works perfectly, however I got messed up with sprite position on that body. Here's what I have now and here's what I ...
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Why is my tiled map moving when I move the camera in libGDX?

I use LibGDX. I have created a map with Tiled Map Editor and loaded it to the game. Everything else is working well, but when I move the camera, the map moves: it jumps or floats. My code: public ...
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1answer
12 views

Box2dWeb: rotating object about a point

I am having problem rotating box2d object back and forth around a point. To better understand my problem i have prepared an example clicking on key rotate the paddle when u click again the paddle ...
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29 views

Java Libgdx Attaching Sprite to Box2D Body

So I am working on programming a java 2D platformer for fun on the side and I have a rendered TMX level and a box2d body (just a circle shape) that I am currently using as my player. All the controls ...
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25 views

How can I simulate a basketball throw in LibGdx box2d?

So I want to simulate a similar throw like in the game Bouncy Basketball. Do i need to create a body and attach another body on it that would be the arm and then how would I apply force/impulse to the ...
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15 views

Box2d capsule stumbles on ground

I am working on a game with box2d and sdl. I Created a character and some boxes as ground, but faced the problem where the character would run a few meters, and stumble on one of the boxes' edge. I ...
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48 views

Box2D Physics Crazy

I have a simple Box2D Game with a dynamic player, a static floor, and a matrix of gems. The problem is that the physics engine goes crazy. You can see in this video: https://youtu.be/iaH_ex8eVVk ...
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Sprite not drawn on the same position as its Body LibGDX after implementing Pixels Per Meter Division on Box2D

I had a problem where the sprite was not positioned on Body correctly which I solved and you can see it here: Box2D is not positioned on the sprite correctly LibGDX After I solved that, I needed to ...
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55 views

How to handle two players playing on one keyboard with Box2D (LibGDX)?

I'm making a racing game with LibGDX and Box2D. I've been using this tutorial to implement the basic physics, and it works properly. My main problem is to implement two different sets of keys ...
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2answers
45 views

Box2D is not positioned on the sprite correctly LibGDX

I have a strange issue where my Box2D is not being positioned on the player correctly. Down is the picture: What I find more strange is that the Box2D is positioned correctly on the cloud that is ...
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2answers
82 views

Why is my character passing through in Box2D?

I have a collision problem in Box2D. I am trying to do a simple platform game with Libgdx, Box2D and TiledMap. I have a map made with TiledMap: I load the map in my Android game. I read all the ...
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1answer
35 views

LibGDX--constant high score in top corner

I'm currently programming a game using LibGDX and box2D. I have a sprite (player) that moves up the screen, kind of like doodle jump. I'd like to have my camera to be centered around the player at ...
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1answer
38 views

Box2D fixed timestep updating is twitchy on constant FPS

I'm messing around with libgdx and box2d and I'm trying to implement sidescroller movement with fixed timestep logic according to the famous Fix Your Timestep! tutorial/guide. However, logic updating ...
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2answers
113 views

Box2DLights in libGDX - Bad quality of the light gradient on Android

I am facing a problem while porting one of my libGDX project from desktop to Android : My game uses Box2DLights. While the light effect look very fancy on the desktop version of the game, it looks ...
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35 views

How to Implement a 2d camera object for a side scroller game

Ok so Heres the problem. I'm Using c++ with sfml for graphics and box2d for physics. I've tried an ultra simple cam movement in the past where i lock the player to the center of the screen and offset ...
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1answer
28 views

Libgdx + Box2d working with 2 cameras

Recently I have read that you can work with 2 cameras whenever you involve Box2d, which only works in meters. In my Renderer class, I receive all the entities in the game and then draw them. I work ...
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37 views

Box2D top down car weird spasm

im currently programming a 2d top down racing game with box2d and libgdx. i have a car body to which there are 4 wheels attached. these 4 wheels are attached with RevoluteJoints ( for the front ...
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62 views

Problem merging vertices of two polygonial bodies

SUMMARY I need help to create a weld joint that fixes the two bodies together in a way as illustrated in the first image. ISSUE I am having an issue where I cannot find out how to weld vertices of ...
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3answers
192 views

Box2d set sprite to body that rotates around specific point

I want to rotate kinematic body around a specific point (I already done this part using shape.setAsBox(1.8f / PPM, 0.2f / PPM, new Vector2(5.2f, 0), 0); What I try is this: PolygonShape shape ...
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64 views

Box2d - Texture lagging and flickering

I'm having issues with texture rendering in my game. I've done a lot of research and repeated the same steps of tutorials over the internet to render and update Sprite positions properly. Somehow, ...
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52 views

Libgdx and Box2D TiledMap render is not smooth

I'm building simple side scroller game. My player (square) move fast and it interacts with other world objects. Problem is when my player is moving it seems that all world is rendering somehow strange ...
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42 views

Libgdx box2d bodies go through other bodies

I'm developing a game using libGDX and box2d. I am facing a problem that bodies go through each other... I'm moving the body using a TouchPad by setTransform. I think the problem is that I use ...
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LibGDX: Is there any way to check if space between 2 bodies is free?

I know how to calculate the distance between 2 bodies in my game using Math.hypot(x,y); but I need to know if between those bodies the space is free, I mean, without any body.
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32 views

LibGDX & Box2D Actor Collision

I'm working on a LibGDX project, and I was wondering about the best way to define actors in a collision. I know this is probably a common question, but specifically I'm interested in beefing up one ...
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31 views

ChainShape in Box2D

I recently began to learn libgdx and I am stuck at a problem with the CainShape of Box2D. My first goal is to simply create a box with a ChainShape. In order to achieve that, I added four Vector2 ...
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23 views

Libgdx moving a body sequence

How can I move a body (box2d) to different points in an order. Like first it moves to 100,200 then to 200, 450 and so on? I've tried actions(and actor) but I can't get the point where the body is ...
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1answer
67 views

LibGDX Box2D texture on dynamic generated body

I'm creating a game that is similar to hill climb racing. I've generated the ground and now I want to add texture to the ground. Here is a screenshot of a game Here is my code (I create ground using ...
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libgdx box2d car wheel circle collision with ground

I'm creating game similar to hill climb racing. I have created car (which is basically polygon with two circles) and ground generated by sinus. Now here is the problem: when my car try to climb in ...
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Libgdx Box2D random positions and intervals falling bodies

I need to make that objects fall from the top of the screen random intervals and positions. Here's my code where I create lot of objects and add them to ArrayList private void createBalls() { ...
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1answer
50 views

Problems managing collision filtering

I have my character fixture and body(is a tank), so when I press the screen it throws a rocket(which also has a body and a fixture) that the player can controlll touching the screen. My game also has ...
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1answer
55 views

How to make a ball hit many tiled circular objects in LibGDX

Hey guys I've been learning to make games with LibGDX. I did a tiled map in Tiled and the rest of code in java using Android Studio. I could make a ball bounce on the flour using Box2D, but I can't ...
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24 views

Box2d How to connect distance joint to the ground?

I have a rectangular fixed size world. I want to connect a body inside it to any place(near that body) in the world with a b2DistanceJoint. Do I need to create a large static body with the size of the ...
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2answers
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Box2D LibGDX Body.getPosition() and Body.getWorldCenter() problems

I have a problem with my game in Java with Box2D and LibGDX I found out that when I use body.getPosition() it is only half of that of body.getWorldCenter(). The problem here is for me that I use ...
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Movement for Box2D Bodies

I'm having trouble wrapping my head around something that should be relatively simple. I'm making a breakout clone using LibGDX and Box2D. I'm also using the Ashley ECS. For movement with bodies, I ...
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59 views

Moving box2D body with texture?

I was following the solution from this http://stackoverflow.com/questions/20180063/box2d-body-with-texture. I ended up getting this working for static bodies. But when trying to get the PolygonSprite ...
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67 views

How to dynamically draw a filled polygon with a given array of vertices?

Say I have a simple array of vertices (or floats with every odd index being the X of a vertex and every even being the Y), how could I paint all the area between the vertices? As in, I have maybe ...
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3answers
134 views

Most optimal way to load 2D world

I am creating a 2D car racing game. (Yes, a Hill Climb Racing clone) What I am doing right now is load 10% of the map every time the user gets to 7%. For example: Imagine the map has 10km. (10000m) ...
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Dealing with collisions across adjacent static bodies

The Problem: I have the following setup: A, B and C are rectangular static bodies in box2d. p is a circular dynamic body in box2d. The movement of 'p' is solely controlled by the current gravity ...
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40 views

Static body bridging two other static bodies

I have two box2d bodies like below, What I need is to create another body that kind of bridges this two bodies. I am not looking for a box2d joint, but a body that will be like a bridge touching the ...
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2answers
105 views

How do I set angular velocity/torque so that it's pointing to velocity/direction?

Right now, when I spawn a shootable object, it goes like this: Because I just set it's angle to this: float aimAngle = (float) Math.atan2(velocity.y, velocity.x); bullet.setBodyAngle(aimAngle); ...
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Get entity at supplied world position LIBGDX

So I'm making a simple 2D rpg. What I need is to be able to interact with the entity that the player is looking at. I need to be able to look at E.g another player in the world and press 'E' and have ...
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How do I make a box don't slide up/walk normally on a slope?

I'm trying to implement slopes in my game. When I walk up the slope and suddenly stop, here is what happens: And when I move down, it goes like this: I have set density to 0.5, friction to 0 on ...
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Should I compute impact damage with energy or momentum?

My game uses physics (Box2D in particular). Just about every object in the game can be destroyed, and the primary method of combat is by slamming objects into one another at high speed. It makes ...
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71 views

LibGDX Box2DLights - Global Illumination

I'm using LibGDX + Box2D to create dynamic lights in my game, but I'm currently stuck. I'm trying to light up every game object in the game with its own shadow, kinda like global illumination. Do you ...
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35 views

Multiple bodies or multiple fixtures for a wall in Box2D?

I am making a game with a sort of "playfield" where the game takes place, acting as boundaries on a top-down shooter. I am using Box2D for physics, and I am questioning which of the following would be ...
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75 views

How to predict future position of an object(bullet sync)?

There is a multiplayer game and server sends to all clients a message when a shot happens, containing bullet position, bullet velocity and timestamp. By having timestamp, we can calculate the lag, ...