Tagged Questions
2
votes
1answer
97 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
120 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
138 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 ...
5
votes
4answers
375 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
74 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
1answer
148 views
Understanding Box2d Restitution & Bouncing
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
206 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
270 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
766 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
177 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
252 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
55 views
limiting a sprites movement after a mouseJoint is released
I have created a weldJoint between two sprites and I also created a method (spritePositionRelease) that returns the exact position of a sprite when a mouseJoint is released. I want to track the ...
0
votes
0answers
132 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 ...
2
votes
1answer
219 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
127 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
101 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,
...
0
votes
0answers
61 views
Creating a contact listener with sprites from different classes
I've been trying to set a contact listener that creates a joint on contact between two sprites which have their own classes. Both sprites are inheriting from NSObject and they are initialized in their ...
2
votes
2answers
536 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
785 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
114 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
445 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), ...
0
votes
1answer
532 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()));
...
0
votes
0answers
2k 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
1k 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
558 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
361 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
484 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
465 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 ...
2
votes
4answers
3k views
box2d and constant movement
i'm developing a game with a top down view, the players body is a circle. To move the character you need to tap on the screen and it moves to the spot.
To achieve this i'm saving the coordinate of ...
4
votes
3answers
535 views
IndexOutOfRangeException on World.Step after enabling/disabling a Farseer physics body?
Earlier, I posted a question asking how to swap fixtures on the fly in a 2D side-scroller using Farseer Physics Engine. The ultimate goal being that the player's physical body changes when the player ...
2
votes
1answer
1k views
how to ignore physics collision of some objects in box2d
I know this sounds silly but I would like some objects to follow physics while others not to collide each other.
I tried to achieve them by setting their position exclusively. But then it will ...
3
votes
1answer
246 views
Why does my ball always bounce perpendicular to walls?
I'm using Box2D.
I think it's something to do with wall's fixture definition, but when a ball goes toward a wall at a 45 degree angle, I would expect it to bounce off at 135 degrees, but it always ...
2
votes
5answers
3k views
Box2D physics editor for complex bodies [closed]
Is there any editor out there that would allow me to define complex entities, with joins connecting their multiple bodies, instead of regular single body entities? For example, an editor that would ...
10
votes
1answer
1k views
Should I write my own physics engine, because of networking integration?
I'm currently developing a top down, realtime, zombie shooter. I'm coding this in Java, using JBox2D as my physics engine. I have been coding the networking this week, and am now up to the physics ...
8
votes
3answers
2k views
How do you do AI path following within a 2d physics engine like farseer/box2d?
I'm in the process of moving a 2d top down game I've been working on into a proper rigid body physics engine like Farseer. Up until now, I had just hacked together my own physics code where needed.
...
2
votes
2answers
437 views
Physics in carrom like game using cocos2d + Box2D
I am working on carrom like game using cocos2d + Box2D. I set world gravity(0,0), want gravity in z-axis. I set following values for coin and striker body:
Coin body (circle with radius - ...
5
votes
2answers
2k views
Physics or Time-Based Animation In Corona SDK (iOS) Using Box2D
I am part way through creating a Doodle Jump clone for iOS using Corona SDK. I'm currently using the physics engine (box 2D). It's not a straight clone, but I need the basic principles in place to ...
2
votes
1answer
1k views
2D physics performance on iPhone/Android using Unity 3D?
I've been looking into making 2D games with Unity. One thing which concerns me is the performance of the physics engine. Since Unity is a 3D game engine I'm going to have to assume it uses a 3D ...
0
votes
0answers
837 views
Multiple spawned objects on collision - Corona SDK
Please help! I'm trying to spawn 5 balls one by one from the sky and have them disappear as soon as they hit the ground or when they hit another user-controlled object that's on the ground. The good ...
1
vote
1answer
669 views
Bodies are colliding but refusing to rotate in Box2D
I'm running box2d in C++ and hooking it up to C# via p/invoke. All physics stuff occurs in C++.
My problem is that bodes know when they are colliding and do so with great precision. However if I have ...
1
vote
1answer
507 views
Dynamic bodies with Parallax Scrolling
I have an object that has a dynamic body. Currently, I'm setting it's position to follow the sprite when the parallax layer move. After a certain event, the object suppose to fall to the ground. ...
4
votes
1answer
195 views
Box2D stable range and position
Box2D marks stable range of object size is 0.1M ~ 10M. This specifies object size range. How about space size? If I make an 1M object at (1000.0f,1000.0f) position? Is it can be stable? Or should I ...
5
votes
2answers
2k views
How to make bird to fly using box2d
I am new to Box2D, I have set gravity to 10. How to make an object fly in space even though the gravity is 10. What are the properties I need to set to make object fly? Is there any different ...
5
votes
2answers
2k views
Is it worth it to use Bullet for 2D physics instead of Box2D for the sake of learning Bullet?
There isn't much more to the question. I'm not concerned about overhead, as I'm sure they are both fine for my purposes. Basically, I am familiar with Box2D concepts because of the Farseer Physics ...
7
votes
3answers
930 views
How to implement 2d explosions that will cause damage taking into account covers and distance?
How can I implement a 2D explosion in a way that it will cause less damage to characters that hide behind crates or other cover? Ideally damage will depend on the strength of the cover (e.g. metal ...
4
votes
3answers
541 views
What do I need to change in Box2D to work in pixels?
Box2D seems to be set up in such a way that you cannot work in pixels (i.e. physics scale = 1). It produces very strange results as it hits maximum speed limits at low speeds and looks very strange. ...
5
votes
1answer
428 views
Strangeness when simulating a chain
I'm using box2d and I simply hook up 10 points each with a similar length constraint to the adjacent point.
When I move 1 point, the others follow just like a rope/chain. Just like one would expect.
...
2
votes
1answer
829 views
cocos2d: syncing CCAnimation frames with Box2d Shape manipulations
my cocos2d game currently has a ccsprite attached to a box2d body.
during the game i apply different CCAnimations on my sprite, i would like to perform certain manipulations to the box2d body ...
4
votes
1answer
696 views
Problem with box2d at beggining
I have problem with simple box2d physics: I have two bodies : 1 - static box , 2 - dynamic box. I only want to this dynamic box fall on this static, and lay. But now it looks like that at end , ...
49
votes
5answers
14k views
Good 2D Platformer Physics
I have a basic character controller set up for a 2D platformer with Box2D, and I'm starting to tweak it to try to make it feel good. Physics engines have a lot of knobs to tweak, and it's not clear to ...
