3
votes
2answers
96 views

Why are my Box2D wheels slipping on ground?

I have a car, set up in Box2D as a rectangle connected with two wheels using WheelJoints: The wheels are defined as follows: FixtureDef wheelFixtureDef = new FixtureDef(); ...
0
votes
0answers
19 views

Box2D collision damage calculation from postSolve or not?

I'm using postSolve to get impulse then calculate damage base on that impulse. But there's some issue: Stability The damage isn't stable. When the same ball is hitting with same speed, the damage ...
6
votes
1answer
113 views

How can I predict player-to-projectile collisions in Box2D?

I'm making a real time shooting game with Box2D as the physics engine. The gameplay is mostly about trajectory, like Angry Birds. I want to make a slow motion effect and move camera to the player when ...
2
votes
2answers
43 views

How can I add an impulse to specific rigid bodies at rest?

Scenario Rocks falling down a rocky slope, with a flat surface at the bottom. When they land on the surface, the rocks move slightly before coming to a rest. GLESDebugDraw shows the bright orange ...
0
votes
1answer
29 views

Inertia in flight simulation using box2d

I'm trying to simulate flight using box2d and libgdx. The main problem I am currently experiencing is with inertia: since there is no air, the plane looks like it were drifting. I wasn't able how to ...
0
votes
0answers
42 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 ...
0
votes
1answer
61 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 ...
0
votes
0answers
91 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 ...
0
votes
1answer
79 views

Trying to make sprite float up and down [closed]

Using LibGDX + Box2D and my understanding of the answer posted from this question: Here I apply the following impulse: // modify sprite's Box2d Body object int a = 8; // amplitude int f = 1; // ...
0
votes
1answer
93 views

Box2D + Citrus Engine - Proper Pong Paddles

I am creating a pong clone for my first Citrus Engine project using Box2D. I've tried two types of paddles, both do not fully work. 1) Paddle is a dynamic body with a restitution of 1.0 and friction ...
0
votes
3answers
188 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 = ...
2
votes
1answer
154 views

Using Box2D / Physics with Tiles?

Here is my issue. I currently have Box2D setup and working. But, it works with my Entity system. So I can create static objects and dynamic moving ones, and they simulate fine. However, my world is ...
1
vote
2answers
109 views

How can I get the force of a collision in Love2D?

Is it possible to get the force of a collision between two objects in Love2D/Box2D? If so, how?
1
vote
1answer
76 views

Farseer - Difference between Position, GetLocalVector, and GetWorldVector

I have used Box2D extensively, and am used to just calling body.GetPosition(). But Farseer does not have this. Instead it has a property Position, as well as methods GetLocalVector and GetWorldVector. ...
8
votes
3answers
344 views

Make fast thing look slow (Box2D)

I'm working on a game that you control a trebuchet to throw balls to the opponent. It's like a game called 'Medieval Siege'. When the trebuchet is swinging its arm, player need to seize the best ...
1
vote
1answer
92 views

Box2D relations

As far as I know, the unit in Box2D is meters. When I use Box2D in Processing with JBox2D, I set the "world size" as the window size specified in the setup(). Now I'm wondering if there is any ...
0
votes
1answer
381 views

Box2d making a body follow the mouse accurately

I am trying to make a box2d b2Body follow my mouse position. This is the code I am using at the moment but it is not performing very well: deltaPos = mousePos - body->GetPosition(); deltaPos *= k; ...
1
vote
1answer
100 views

How to reduce the time it takes to speed up an object?

I have a body that I am applying a force to every step. However, I it takes a significant amount of time for it to speed up, which I do not want. Is there some value I can adjust to help with this?
0
votes
1answer
290 views

Showing trajectory indicator

From the image you can see that the ball fired on the left that fire behind it, does not match the calculated trajectory. Im drawing the ball trajectory using an equation from a SO question, this is ...
2
votes
1answer
258 views

How do I make my camera follow a Box2D object?

I'm implementing a camera in my game. It worked 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 center of the screen. ...
2
votes
1answer
315 views

Box2D: Asteroids-Like Spaceship Physics

I'm new to Box2D (JavaScript) (and the world of physics/mathematics) so I'm having a hard time working out the methods I need to use to make a spaceship act like it does in the classic arcade game ...
0
votes
1answer
462 views

Box2d contant speed before and after collision

I want to make my body fly at constant speed, how to make it fly at constant speed before and after collision? I set restitution of my body to 1.0 but after some direct and powerful collisions my ...
3
votes
0answers
133 views

How to make the Angry Birds “shot arch” dotted line? [duplicate]

I am making a game that includes 2D projectile flight paths like that of Angry Birds. Angry Birds employs the notion that a previous shot is shown with a dotted line "arch" showing the player where ...
2
votes
1answer
178 views

Using Box2D for range detection?

I have two entities. One has a sword, one has a bow and arrow. When the bow entity is 100 units away, he needs to begin attacking. Likewise, when the sword entity is 10 units away, he needs to begin ...
2
votes
1answer
326 views

Separation algorithm in flock simulation?

I'm using box2d (the c++ one). I found a method for an arriving behavior (on http://www.red3d.com/cwr/steer/gdc99/ ), which works well, problem is, the bodies are bumping into each other and it ...
0
votes
1answer
280 views

Is there a “box2d without physics” lib (only for collision detection)?

Box2d Collision detection algorithms are probably the best ones out there. Unfortunately, they are bundled together with a realistic physics engine that I don't need. Is there an open source project ...
1
vote
1answer
657 views

Is using Box2D for simulating gravity “in space” a good idea? [duplicate]

I'm attempting to write a simulation of a solar system of planets in 2D space that are attracted to each other through Newton's law of universal gravitation. I know that it is possible to simulate ...
7
votes
4answers
1k views

Making a Box2D ball bounce to constant height

I want to create a game like Doodle Jump. I'm using libgdx and Box2d. I needadvice on how to make my ball bounce constantly and with the same height. I've tried setting the ball's body restitution ...
0
votes
2answers
145 views

Problem with sensor in box2d [closed]

I have two bodies: one green static sensor (spikes) and one orange dynamic body (brick). I have bullet and it's a dynamic body too, but with bullet flag set. My problem is that when the bullet is ...
1
vote
0answers
959 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, ...
2
votes
1answer
443 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
votes
1answer
328 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 ...
4
votes
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 ...
1
vote
2answers
220 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) ...
0
votes
1answer
401 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 ...
0
votes
0answers
138 views

Farseer non-colliding bodies affect eachother

I'm trying to use Farseer to make a tile engine, but bodies that are not colliding with a sprite are still having an effect on it. In this image there is a single sprite(the green box) and a single ...
6
votes
2answers
621 views

Show path of a body of where it should go after linear impulse is applied

I am making a game with Andengine and Box2D. I have a dynamic body and I apply linear impulse on the body to move it around when the user have touched the screen. Now I want to show the path where ...
-1
votes
1answer
149 views

Interacting with box2D objects

How can I interact with an object in box2d, I'm completely new to this so I have no clue what to do. The box is created like this: bodyDef.type = b2Body.b2_dynamicBody; fixDef.shape = new ...
1
vote
1answer
115 views

Why is the MaskBit maxed out

Hi there for some reason the maskbit of my b2FixtureDef is being maxxed out and im not sure why Here is the declaration of the items that are used in the game enum PhysicBits { PB_NONE = 0x0000, ...
2
votes
2answers
940 views

Simple 2D Flight Physics with Box2D

I'm trying to build a simple side scroller with an airplane being the player. As such, I want to build simple flight controls with simple but realistic-feeling physics. I'm making use of cocos2D and ...
2
votes
4answers
1k views

Should I used Box2D for a Flash platformer or use something for gaming like Fixel or Flashpunk?

I'm trying to make a platformer with Flash/AS3 and have been looking for something to help with some of the collision etc. I've look at a few engines and Box2D/WCK seems the most sophisticated. Do I ...
3
votes
1answer
136 views

Smoothly move between bodies

I'm not sure if the title is correct (please comment if it is not). I have a sprite (rectangle body), and I'm applying force on it to make it move from left to right and then go backward. The platform ...
1
vote
1answer
585 views

Box2D platformer movement. Should i mess with velocity?

I have a platformer game in which I implemented the movement using a wheel attached to the hero. For jumping I use this: player.body.applyLinearImpulse(new Vec2(0, 30000000), ...
1
vote
1answer
983 views

JBox2D applyLinearImpulse doesn't work

So i have this line of code: if(input.isKeyDown(Input.KEY_W)&&canJump()) { body.applyLinearImpulse(new Vec2(0, 30), cam.screenToWorld(body.getPosition())); ...
1
vote
1answer
4k 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 ...
5
votes
1answer
3k views

Box2D Difference Between WorldCenter and Position

So this problem has been brothering for a couple of days now. First off, what is the difference between say Body.getWorldCenter() and Body.getPosition(). I heard that WorldCenter might have to do ...
4
votes
1answer
685 views

How to make an object fly out of a slingshot?

At the moment I'm improvising a slingshot, the user can click and drag the projectile and let go. The force on the object is calculated by getting the distance between the vector of the slingshots two ...
0
votes
2answers
629 views

Calculate impulse need on object to throw i Y meters into the air, with varying mass

Say I have an object that has a variable mass. Now I want to apply a vertical impulse (straight up into the air) onto the object, so it always flies up to the same height. How do I calculate this? So ...
2
votes
1answer
704 views

Box2D + Love2D (Lua) - Assertion fail with polygon meshes

When I try to create a triangle collider for my game it sometimes leads to an assertion fail. I use the physics engine that comes with love2d (Box2D). That's the error message that appears when the ...
4
votes
1answer
573 views

Multiplayer box2d networking for turn based game

I am currently in the planning stages for a 2D game for mobile devices which I will be making in C++ using cocos2d-x. The game will be turn based and each turn will have a phase in which the physics ...