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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239 views

How do I change the speed of an object without changing path travelled?

I have a ball which is being thrown from one side of a 2D space to the other. The formula I am using for calculating the ball's position at any one point in time is: x = x0 + vx0*t y = y0 + vy0*t - ...
6
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1answer
1k views

How does 2D Game Physics work? [duplicate]

Possible Duplicate: How do I build a 2D physics engine? If we take the game Angry Birds that had big success lately I were thinking how do they implement the physics in a game like that? ...
6
votes
3answers
4k views

Box2D Check If Point Intersects a Body

Is there a way to check if a point is intersecting a body? For example, lets say there's a body in the world at a position of (100,100). Is there a way to check if a point at (100,100) intersects ...
6
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1answer
1k views

What causes Box2D revolute joints to separate?

I have created a rag doll using dynamic bodies (rectangles) and simple revolute joints (with lower and upper angles). When my rag doll hits the ground (which is a static body) the bodies seem to ...
6
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3answers
2k views

Is there a good existing starting point for realistic 2d racing car physics?

I'm trying to get a realistic behaving racing car into my 2d top-down game. Making a very simple car that drives around is straight forward but I want a reasonably sophisticated model that models ...
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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...) ...
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2answers
2k views

How can I implement rectangle collision response?

I am working on a game in JavaScript and my current implementation of collision uses the shortest distance to push the intersecting object away, which isn't always correct. I've made this diagram of ...
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3answers
2k views

Implementing a 2D Platformer Game Engine

Any ideas where I can find info about making 2D jump & run games? I need some general ideas, so I wouldn't reinvent wheel (at least where game design is concerned). Another point is that I am ...
5
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4answers
348 views

How do I model a gooey sprite?

I happened to see this structure of a gooey player character made in flash. Can anybody suggest onto what computer science concept I should use to make a goo make it behave like a goo Thanking ...
5
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1answer
399 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 ...
5
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4answers
573 views

Channelling an explosion along a narrow passage

I am simulating explosions in a 2D maze game. If an explosion occurs in an open area, it covers a circular region (this is the easy bit.) However if an explosion occurs in a narrow passage (i.e ...
5
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3answers
584 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 ...
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2answers
573 views

Whats the physics behind the doodle jump game?

I'd like to know how we can achieve the doodle jump type physics using andengine. I mean the character is not colliding with the ground blocks when he moves upwards but will collide when he came ...
5
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2answers
481 views

Ball bouncing infinitely and constantly

Alright, so I've got hold of some simple physics mechanics, and am currently trying to implement bouncing. Based on the first answer of this question, I've developed the following algorithm: ...
5
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5answers
2k views

How to lead a moving target from a moving shooter

I saw this question: Predicting enemy position in order to have an object lead its target. My situation is a little different though. My target moves, and the shooter moves. Also, the shooter's ...
5
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1answer
193 views

Physics/Logic behind self-bounce

I have a game that I am currently working on and I have a problem. What would a ball look like when it makes itself bounce. Say, for example that the ball had its own "inner power", was made out of ...
5
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1answer
1k views

Creating similar effects of Geometry Wars in 2D only

I want to create a game with similar effects to that of "Geometry Wars"... for those who have never played the game, basically, massive amounts of 'bending' and 'warping' effects are done on the ...
5
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1answer
150 views

Tracing a 2d path through multiple gravity fields

For a projectile starting at origin O, an initial velocity V, and several stationary planets P[n], how would I pre-calculate and store the path it would take without actually stepping through each ...
5
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2answers
2k views

2D soft-body physics engines?

Hi so i've recently learned the SFML graphics library and would like to use or make a non-rigid body 2D physics system to use with it. I have three questions: The definition of rigid body in Box2d is ...
5
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4answers
6k views

2D AABB collision response

I'm making a simple platformer, and I wanted simple collision handling. So I gave all my objects an AABB hitbox and tried to resolve collisions. However, I can't get it to work. My main character has ...
5
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3answers
613 views

Physics for Android Game

I'm making a 2D game for the Android phone, one that involves falling balls. I want to use a physics engine to properly simulate the balls falling and hitting other objects. I'm currently using ...
5
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3answers
320 views

How do you calculate the rotational velocity of a flying object?

When a arrow shaped object is fired it slowly adjusts it's rotation to match the direction it is moving. But what is the actual physics behind it? The question is: How many degrees does the ship ...
5
votes
1answer
534 views

Pseudo-magnet implementation with chipmunk

How should I go about implementing "natural" magnet on a certain body in chipmunk space? Context is of simple bodies lying in the space (think chessboard). When one of the figures is activated as a ...
5
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2answers
457 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 ...
5
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2answers
799 views

Collision response for 2D racing game

The title is fairly self-explanatory. I have a 2D racing game that utilizes per-pixel collision detection (the track is essentially two bitmaps, one for the graphics, one for collision data). The ...
5
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1answer
458 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. ...
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3answers
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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 ...
4
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1answer
1k 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
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2answers
904 views

A good place to learn about Game Programming with Mathematical Vectors?

I am looking for a place in the web where I can turn my current game development process into a vector based approach. I am sorry If this question has been asked once. According to my google search ...
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3answers
117 views

Propel entities at some angle (depending on explosion's position)

I have a 2D platformer. There are multiple particles that are just 1x1 colored pixels. Let's assume there are 256 particles laid out as a 16x16 cube. Say I popped an explosion right in the middle. All ...
4
votes
1answer
383 views

How to balance a ball on a rotating plane?

I'm doing some research and I really don't want a physics engine when a simple mechanism will do. I have a ball that will be balanced on a plane. The ball will always be "stuck" to the plane and ...
4
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2answers
364 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. ...
4
votes
1answer
651 views

Implementing jumping and heightmaps in 2D RPG/Adventure style games?

I've been putting together, albeit slowly, a traditional style game engine in flash/AS3 along the lines of Alundra/Final Fantasy 3/etc etc.. Everything so far is working smoothly (maps from XML data, ...
4
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3answers
565 views

2D physics library that supports curved surfaces and inverse or boolean shapes?

I've been using box2D for a few months, but I now badly need a physics library which can use boolean shapes (ie; cutting a circle out of a square) and/or curved surfaces. Does anyone have any ...
4
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2answers
435 views

How to circle a target at a constant distance

I have an AI ship that stops approaching when it gets within firing range, and starts strafing around its target. The problem is that it doesn't circle its target very well. The following code ...
4
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1answer
438 views

Algorithm for randomly generating reachable platforms

I want to randomly generate reachable platforms on the fly for a 2D game. Right now, I am just creating platforms at random x,y positions. Only 4 platforms can exist at once, so once the 5th one is ...
4
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2answers
279 views

Creating stable tentacle structures

I am using verlet integration to simulate some tentacles. So far it works great and I am satisfied with how it looks in general. Here is how a tentacle is built: The very stiff sticks are colored ...
4
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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 ...
4
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2answers
669 views

Tracking Object Position - Firing on a Trajectory

How can I calculate the position of an object after "firing" it from a fixed point? I am to create a small game - most likely with canvas (pure HTML, JS based) or Adobe Flash - in which the player ...
4
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1answer
366 views

Good book or tutorial for learning how to apply integration methods

I'm looking to animate a graph layout using edges as springs and nodes as weights (a node with more links will have a bigger weight). I'm not capable of wrapping my head around the usage of ...
4
votes
2answers
1k views

How to create simple physics for a group of balloons colliding in the screen (2D)

The game is 2D, how can I make simple physics for a group of balloons colliding in the screen. What I need is the balloons not to overlap and to bounce when they reach the limits of the screen or ...
4
votes
4answers
634 views

Point of contact of 2 OBBs?

I'm working on the physics for my GTA2-like game so I can learn more about game physics. The collision detection and resolution are working great. I'm now just unsure how to compute the point of ...
4
votes
1answer
940 views

How to make a 2D Soft-body physics engine?

The definition of rigid body in Box2d is A chunk of matter that is so strong that the distance between any two bits of matter on the chunk is completely constant. And this is exactly what ...
4
votes
3answers
695 views

Calculating buoyancy force

I am trying to simulate a buoyancy force for objects submerged/suspended in a fluid in a 2D environment. According to Game Physics: Engine Development: How to Build a Robust Commercial-Grade Physics ...
4
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2answers
376 views

Which techniques to study? [closed]

Just to give you some background info, I'm studying a programming major at a tertiary level and am in my third year, so I'm not a newbie off the street. However, I am still quite new to game ...
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 ...
4
votes
1answer
344 views

How to take into consideration the effect of initial rotation of a ball hitting & reflecting off a surface

Hey all, I am trying to take into consideration the effect of inertia of the initial rotation of a ball, hitting a surface, into the exit velocity vector of the ball. My current theory is this: ...
4
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1answer
218 views

How do I simulate a trampoline?

I'm quite new to game development. I was pretty impressed with the elastic effect I saw in this flash game when the ball hits the trampolines and I'm wondering how to recreate it. I've done some ...
4
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1answer
112 views

How to manage sleep/awake state of physics body

I have a loop, which updates all the physics, inside the loop I'm updating the position of the objects, first thing is the gravity, which pulls all the objects to the bottom. Now my question is, how ...
4
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1answer
442 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> ...