Relating to the motion of objects through space (in 2 dimensions (x,y)) and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.

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27
votes
11answers
5k views

Do 2D games have a future? [closed]

I'm currently working on a 2D soft-body physics engine (since none exist right now -_-), but I'm worried that there's no point to spending what will most likely be years on it. Although I love ...
12
votes
3answers
3k views

2D game collision response: SAT & minimum displacement along a given axis?

I'm trying to implement a collision system in a 2D game I'm making. The separating axis theorem (as described by metanet's collision tutorial) seems like an efficient and robust way of handling ...
58
votes
5answers
21k views

Good 2D Platformer Physics [closed]

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 ...
1
vote
1answer
201 views

Game Physics: Implementing Normal Reaction from ground correctly

I am implementing a simple side scrolling platform game. I am using the following strategy while coding the physics: Gravity constantly acts on the character. When the character is touching the ...
0
votes
1answer
213 views

How to implement physical effect, perspective effect on Android

I'm researching about 2D game for Android to implement an Android Game Project. My project looks nearly like PaperToss. Instance of throwing a page, my game will throw a coin. Suppose that I have a ...
2
votes
1answer
478 views

What's the best way to handle slopes for a platfomer game using Box2D

I would like to know if there is any known solution for handling the player's movement on slopes using Box2D engine. I tried to do it using a circle as the player. Everything was fine until I tried ...
0
votes
2answers
508 views

Circle physics and collision using vectors

This is a problem I've been having, When making a set number of filled circles at random locations on a JPanel and applying a gravity (a negative change in the y), each of the circles collide. I want ...
5
votes
3answers
503 views

'Spring' physics

I'm trying to put together a struct or a method of some sort that will allow me to check the relative position between two objects, and if they're too far apart, apply a force that will draw them ...
3
votes
3answers
680 views

Moving a body in a specific direction using XNA with Farseer Physics

I have a custom polygon attached to a body, which looks like this: What I am trying to accomplish is getting the body to move according to wherever the tip of the body is. So far this is what I've ...
2
votes
3answers
1k views

Game physics / 2D Collision detection AS3

I know there are some methods you can use like hittestPoint and so on, but I want to see where my movieclip colliedes with another another movieclip. Any other methods I can use? by any chance does ...
3
votes
2answers
410 views

Collisions between moving ball and polygons

I know this is a very typical problem and that there area a lot of similar questions, but I have been looking for a while and I have not found anything that fits what I want. I am developing a 2D ...
0
votes
2answers
235 views

How to apply numerical integration on a graph layout

I've done some basic 1 D integration, but i can't wrap my head around things and apply it to my graph layout. So, consider the picture below: if i drag the red node to the right, i'm forcing his ...
4
votes
2answers
319 views

Detecting a ledge in Box2D [duplicate]

Possible Duplicate: Detect Open Space in Farseer How do I detect ledges? I'm making a 2D platformer with Box2D. The player needs to be able to grab onto a ledge and pull him/herself up. ...
2
votes
2answers
387 views

One-way platform collision

I hate asking questions that are specific to my own code like this, but I've run into a pesky roadblock and could use some help getting around it. I'm coding floating platforms into my game that will ...
4
votes
1answer
846 views

Friction in 2D game

I'm developing a 2D platformer, although this question could probably apply to just about any 2D type physics; What is the equation for friction? I have sort of a hacky type of friction set up in my ...
4
votes
1answer
358 views

2D Magnet-like repelling behavior

If somebody wanted to develop a system between two intersecting rectangles so that the rectangles would, in a gradual process, push eachother away from one another until no longer intersecting, with ...
1
vote
1answer
520 views

How make a laser path prediction line like a “slingshot cowboy” game?

How so I make a laser path prediction line like a “slingshot cowboy” game in cocos2d or box2d and select the target like "slingshot cowboy" game.
1
vote
1answer
294 views

Ideas for 2d fire simulation [closed]

I want to simulate a fire in a flat and non flat* surface (fire spread modelling). I've seen that cellular automata is one of the algorithms that can be used. Are there other algorithms that would be ...
1
vote
1answer
170 views

2D Physics Engine to Handle Shapes Composed of Multiple Densities XNA

The game I'm working on involves shapes that might be composed of multiple materials in a variety of ways. Let's just take for example a wooden rod with and sizable tip of iron or say a block composed ...
2
votes
1answer
762 views

Collision Detection for a 2D RPG

First of all, I have done some research on this topic before asking, and I'm asking this question as a mean to get some opinions on this topic, so I don't make a decision only on my own, but taking ...
1
vote
2answers
128 views

How to fetch only the sprites in the player's range of motion for collision testing? (2D, axis aligned sprites)

I am working on a 2D sprite game for educational purposes. (In case you want to know, it uses WebGl and Javascript) I've implemented movement using the Euler method (and delta time) to keep things ...
3
votes
3answers
244 views

Physics System ignores collision in some rare cases

I've been developing a simple physics engine for my game. since the game physics is very simple I've decided to increase accuracy a little bit. Instead of formal integration methods like fourier or ...
5
votes
2answers
409 views

Multiple collisions within a single frame cycle?

So say you want to simulate several objects in two dimensions, just bouncing around in a finite space. Using AABB and sweep tests, it shouldn't be that complicated to calculate single collisions ...
2
votes
1answer
359 views

android game-logic for shooter

Im creating a 2d game for android. I'll just get right to it. I have a sprite controlled by a joystick that needs to shoot, sofar Ive managed to get direction and movement on my bullet, but then I ...
1
vote
1answer
243 views

Stopping an object after applying an impulse or force?

I'm having a small issue where after applying an impulse or force it is impossible to actually get an object to stop, i.e. a velocity of zero. This code is run every 1 / 60 of a second: void ...
8
votes
1answer
985 views

What is the difference between an impulse and a force related to a physics engine?

What is the difference between an application of an impulse and an application of a force in relation to a physics engine?
1
vote
1answer
1k views

Vector movement in space type game (Mouse rotation)

I'm having an issue with my movement in my 'game' prototype. It's basically not working and admittedly my knowledge with vectors is lacking. The issue I'm running into is that the ship won't move in ...
3
votes
1answer
466 views

How to bounce a 2d point particle off of a circular edge

In a prototype I'm building, a particle can spawn anywhere within a larger, confining circle. Important to note is that the particle will not spawn in the origin of the larger circle, but anywhere ...
1
vote
1answer
674 views

What is wrong with my Dot Product?

I am trying to make a pong game but I wanted to use dot products to do the collisions with the paddles, however whenever I make a dot product objects it never changes much from .9 this is my code to ...
8
votes
2answers
937 views

What is the best way to handle simultaneous collisions in a physics engine?

I'm writing a 2d physics engine in javascript so that I can learn more about physics in video games. I have it working correctly for rigid body collisions, except for if any body collides with two or ...
4
votes
1answer
1k views

How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision ...
1
vote
2answers
303 views

How do I interpolate air drag with a variable time step?

So I have a little game which works with small steps, however those steps vary in time, so for example I sometimes have 10 Steps/second and then I have 20 Steps/second. This changes automatically ...
0
votes
2answers
3k views

What fluid simulation system is used in iPhone games? [closed]

Does anybody know what kind of system developers are using for fluid simulation in iPhone games? It doesn't seem like they're using a Navier-Strokes simulation to me.
4
votes
3answers
2k views

How can I make my main character move in a parabolic arc when jumping?

I'm entering Android game development, and I already have a computer version of a game I want to publish. The thing is, I want to make this as good as it can be. With that said, I need a physics ...
1
vote
2answers
874 views

How do I determine which side of the player has collided with an object?

I have some static bodies (platforms) and a dynamic body (the player) in my world. The collision between them works great, but I would like to know which side of the player (rectangle) collides with ...
1
vote
2answers
282 views

Building a shape out of two rectangles

I would like to build a body with Farseer out of two rectangles so it looks like this: I am a real beginner, so please describe it carefully. Thanks in advance!
0
votes
1answer
417 views

Specific Physics Lessons and Reference for Game Development

What "Physics stuffs" should I learn in game developments? I'm reading about Verlet Integration, and I'm wondering what other lesson should I learn and if there are available resources can you please ...
2
votes
1answer
853 views

How to implement Ragdoll physics to 2D characters in XNA?

I'm starting a new project with XNA. I want to create a game where the main character is subject to ragdoll physics when killed. I was wondering if anyone can give me any tips on how should I ...
1
vote
1answer
355 views

Ball Physics : Bounce height altered by elasticity of ball and bounce surface

I have created a bouncing ball simulator using XNA and I am happy with my use of gravity, acceleration, change of direction and friction/spin. However, I am now at a stage where I would like to ...
2
votes
0answers
308 views

how to attach a body to a rope and making it swing to another rope

I've set some ropes (using cocos2d and box2d) and would like to attach a body to one rope in such a way that it can swing to another rope. I am not sure how to go about this. I read making and object ...
4
votes
3answers
3k views

Implementing Separating Axis Theorem (SAT) and Minimum Translation Vector (MTV)

I was following codezealot's tutorial on SAT and MTV and trying to implement it myself but I've come a cropper when it comes to getting the correct MTV. Here is my example: (Cue pretty pictures...) ...
0
votes
1answer
396 views

BOX2D Kinematic Platform with parallax layer

I am using a kinematic body for my moving platform on x-axis, so I set the linear velocity to b2vec2(5,0). When the player jump on the platform, it works like it is suppose to. But the thing is ...
1
vote
1answer
563 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), ...
3
votes
1answer
1k views

Box2D platformer movement. Are joints a good idea?

So i smashed my brains trying to make my character move. As i wanted later in the game to add explosions and bullets it wasn't a good idea to mess with the velocity and the forces/impulses didn't work ...
1
vote
1answer
885 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
0answers
212 views

Debugging Minimum Translation Vector

I implemented the minimum translation vector from codezealot's tutorial on SAT (Separating Axis Theorem) but I'm having an issue I can't quite figure out. Here's the example I have: As you can see ...
2
votes
2answers
583 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 - ...
2
votes
3answers
2k views

Car movement in arcade racing game

I am finishing a very basic 2D racing game with top-down perspective. I can't get the appropriate formulas to make the movement of the cars fun and addictive... Do you have tips on how to achieve that ...
1
vote
1answer
170 views

How to pin a body in case of collision in Box2D or Farseer?

I'm trying to get an understanding for the Box2D/Farseer physics engine by implementing a small air hockey simulation. There, I have the problem that the CPU player attacks the puck, kicks it, but ...
4
votes
1answer
431 views

Making a multi-pieced rectangular breakable body with Farseer

Using Farseer 3.3.1 I want to create a rectangular BreakableBody with many pieces. Right now here is my code: Vertices polygon = PolygonTools.CreateRectangle( 2.5f , 1.25f ); List<Vertices> ...