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

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2
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3answers
2k views

2d Collision detecton axis aligned boxes

I have recently run into some trouble with my collision detection. My game is composed of a map made out of axis aligned squares. The player has an x and y velocity, and I want to know how I can find ...
1
vote
1answer
249 views

Mouse joint isn't restricting the ball from going to the other part of the screen

I'm developing a application in cocos2d using the Box2D framework, but unfortunately I am having issues. I'm not able to restrict the orange ball in the half screen area, taking the image below as ...
0
votes
2answers
253 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 ...
9
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1answer
4k views

Basic Box2D collision detection

I don't understand how to listen for collisions in Cocos2D/Box2D. Say I have two dynamic circle bodies. One is very small and the other is relatively large. When the small circle collides w/ the ...
8
votes
1answer
640 views

Finding the point of collision

I'm writing a 2D rigid body simulator. The objects being simulated are convex polygons. My question involves how to decide on the "point" of collision, so that when I apply a response force, I can ...
3
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2answers
1k views

When and how should I apply forces in a Cocos2D + Box2D game?

I have some small circles just rolling across the bottom of the screen in my Cocos2D/Box2D iOS app. The bodies are dynamic... so I make them roll by applying a horizontal force to the center of mass ...
12
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4answers
1k views

Animated examples of different interpolations formulas: any link? [closed]

I remember having spotted a link to a huge page with different equations to non linear interpolation curves, for example if you want to stop a car smoothly, etc. Those can sometime be useful to ...
9
votes
2answers
1k views

Physics for a 2.5D platformer with a plane that curves

I'm creating a 2.5D platformer in XNA which uses 3D models that are constrained to travelling along a 2D plane (just like Trine). To make things tricker, however, I want the 2D plane itself to be ...
9
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1answer
2k views

Adding air drag to a golf ball trajectory equation

I'm developing a 2D golf game in VB.NET 2005, but I am stuck on how to implement air or wind drag that should affect the ball. Already I have these equations for projectile: Vo ...
8
votes
3answers
2k views

Kepler orbit : get position on the orbit over time

I'm developing a space-simulation related game, and I am having some trouble implementing the movement of binary stars, like this: The two stars orbit their centroid, and their trajectories are ...
3
votes
2answers
1k views

Why are my objects becoming permanently stuck to walls using Box2D?

I setup a simple simulation environment something like billiards. There are four circle balls (dynamic) and four box walls (static). Simulation works... except one thing. Sometimes when a ball rest ...
4
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1answer
261 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 ...
1
vote
1answer
3k views

Best 3D Physics Engine to use with Ogre [closed]

I am looking for a good physics engine to use with an Ogre game I'm writing. I would prefer for it to be free, open source, mature, simple to use, easy to learn, and flexible. I'm currently thinking ...
3
votes
2answers
431 views

Silverlight scrolling with camera

I'm trying to get my head around scrolling a 2D map that uses a physics engine. If I was to launch a projectile, would I actually be applying the physics to the background images rather than the ...
3
votes
1answer
512 views

Maximum range of projectile fired at given force and elevation

I've gone over this again and again, and my result is obviously wrong when viewed in-action. Here's the initial formula I converted (first one): http://en.wikipedia.org/wiki/Range_of_a_projectile ...
6
votes
1answer
830 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 ...
6
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 ...
2
votes
2answers
358 views

I'm looking for a paper from Teknikus.dk

I'm looking for this great paper about Verlet integration: http://www.teknikus.dk/tj/gdc2001.htm I've found this link on many websites, forums, blogs, everyone is recommending it ! The website is ...
4
votes
2answers
506 views

Particle and Physics problem

This was originally a forum post so I hope you guys don't mind it being 2 questions in one. I am making a game and I got some basic physics implemented. I have 2 problems, 1 with particles being ...
4
votes
1answer
380 views

Good book or tutorial for learning how to apply integration methods [closed]

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 ...
1
vote
0answers
564 views

Cocos2d and Body with few collision shapes using chipmunk [closed]

I'm using Cocos2d (0.99.5) with chipmunk physics engine. Currently I'm trying to place a body into space which is combined from few circle shapes. Let's say I have a corresponding sprite image with ...
4
votes
1answer
841 views

Angular Velocity

Hey, I have a particle that is hit with a force F at a particular position on the ball P. How can I calculate the angular velocity of the X,Y and Z axis? The actual rotating of the object should be ...
5
votes
4answers
1k views

Physics timestep questions

I've got a projectile working perfectly using the code below: //initialised in loading screen 60 is the FPS - projectilEposition and velocity are Vector3 types gravity = new Vector3(0, ...
2
votes
2answers
2k views

Find meeting point of 2 objects in 2D, knowing (constant) speed and slope

I have a gun which fires a projectile that has to hit an enemy. The problem is that the gun has to be automatic, i.e. - choose the angle in which it has to shoot, so that the projectile hits the enemy ...
2
votes
1answer
617 views

Calculate the initial velocity of a 3D trajectory

I've got a 2D projectile code sample working, but would like to extend it to 3D. How would I calculate the initial velocity of the Z-axis? At the moment, I've got: initVel.X = (float)Math.Cos(45.0); ...
9
votes
2answers
2k views

Simulating an object floating on water

I'm working on a top down fishing game. I want to implement some physics and collision detection regarding the boat moving around the lake. I would like for be able to implement thrust from either the ...
3
votes
3answers
368 views

Adding 'swerve' to a direction

I'm not much of a maths expert, so this is probably quite straight forward. I was playing a soccer flash game where you take free kicks. You provide Power, Swerve and Direction. I'm reading up on ...
7
votes
5answers
940 views

Is it possible to have vehicles with physics like GTA in an MMO game?

I haven't seen any MMO games with vehicles with realistic physics and that could achieve high speed, why? Is it because of network bandwidth limitations? Second Life has vehicles, but physics are ...
10
votes
4answers
3k views

How to build a bones animation engine?

I want to develop a flash game. It would draw a stick man, and edit his pose. I think what I need to learn are bones animation and physics engine. Can anyone introduce some good resources to learn ...
3
votes
1answer
345 views

Approximating walking physics via simpler sliding physics

I am modeling walking insects. I implement them as cuboids and use forces (including friction and drag), to control motion. However, the movement characteristics of this 'sliding box' physics don't ...
2
votes
2answers
2k views

Using box2d DrawDebugData with multi layer scene?

In my Game, a Scene is composed by several layers. Each layer has different camera transformations. This way I can have a layer at z=3 (GUI), z=2 (Monsters), z=1 (scrolling background), and this 3 ...
1
vote
1answer
207 views

2D Game Physics: How to evaluate when an accelerating ray is close to a point?

Given a ray in a 2D world at position p with initial velocity u and acceleration a how can I tell when it's within a certain distance r from a certain point.
1
vote
1answer
600 views

How to use the chipmunk physics-engine?

I am developing a game demo where I want a physics simulation with balls and obstacles. I know that this is possible with the chipmunk physics-engine but I don't know how to use it. Can anybody give ...
14
votes
1answer
2k views

Any fixed-point portable open-source 3D physics engines?

I'm looking for a fixed-point 3D physics engine (basic kynematics and collision detection-resolution... nothing too fancy.) I need fixed-point math because I'd like to have deterministic results, for ...
1
vote
2answers
2k views

Voronoi regions of a (convex) polygon

I'm looking to add circle-polygon collisions to my Separating Axis Theorem collision detection. The metanet software tutorial (http://www.metanetsoftware.com/technique/tutorialA.html#section3) on ...
12
votes
1answer
3k views

Separating physics and game logic from UI code

I'm working on a simple block-based puzzle game. The game play consists pretty much of moving blocks around in the game area, so it's a trivial physics simulation. My implementation, however, is in ...
18
votes
6answers
2k views

AI control for a ship with physics model

I am looking for ideas how to implement following in 2D space. Unfortunately I don't know much about AI/path finding/autonomous control yet. Let's say this ship can move freely but it has mass and ...
0
votes
0answers
227 views

Simple project - make a 3D box tumble and fall to the ground [duplicate]

Possible Duplicate: Resources to learn programming rigid body simulation Hi guys, I want to try learning rigid-body dynamic simulation. I have done a fluid and cloth simulation before, but ...
3
votes
1answer
690 views

Breakout clone, how to handle/design for collision detection/physics between objects?

I'm working on a breakout clone, and I wish to create some realistic physics effects for collision - angles on the paddle should allow the ball to bounce, as well as doing curve balls etc. I could use ...
6
votes
1answer
262 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 - ...
11
votes
3answers
10k views

Is there an algorithm for a pool game?

I am looking for algorithm to calculate direction and speed of balls in a pool game. I am sure there has to be some type of open source code for this since pool games are some of the oldest computer ...
3
votes
1answer
561 views

How to restrict paddle movement using Farseer Physics engine 3.2

I am new to using Farseer Physics Engine 3.2(FPE), so please bear with my questions. Also, since FPE 3.2 is based on Box2D, I have been reading Box2D manual and pieces of code scattered in samples to ...
4
votes
2answers
434 views

How to detect and collide two elastic line segments?

There are 4 moving physical nodes in 3D space. They are paired with two elastic line segments / strings (1 <-> 2; 3 <-> 4). Part I: How to detect the collision of two segments? Part II: On the ...
4
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1answer
2k views

2D game - Missile shooting problem on Android

I have to make a tank that sits still but moves his turret and shoots missiles. As this is my first Android application ever and I haven't done any game development either, I've come across a few ...
6
votes
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? ...
3
votes
3answers
815 views

2D Ragdoll - should it collide with itself?

I'm working on a ragdoll fighting game as a hobby project, but I have one dilemma. I am not sure if my ragdoll should collide with itself or not, i.e. if ragdoll's body parts should collide. 2D ...
1
vote
1answer
291 views

Determining relative velocities on impact?

I'm trying to figure out a way to determine the relative velocity of a body colliding with another in a 2D environment. For example if one body is moving at (1,0) and another traveling behind it ...
1
vote
1answer
809 views

gpgpu vs. physX for physics simulation

First theoretical question. What is better (faster)? Develop your own gpgpu techniques for physics simulation (cloth, fluids, colisions...) or to use PhysX? (If i say develop i mean implement existing ...
13
votes
3answers
2k views

Powder games: how do they work?

I recently found these two gems: http://powdertoy.co.uk/ http://dan-ball.jp/en/javagame/dust/ My question is: How are the physics with so many elements efficiently handled? Am I just severely ...
6
votes
2answers
487 views

Physics in my game confused after restructuring the Game loop

I'm on my way with making a game in Java. Now I have some trouble with an interpolation based game loop in my calculations. Before I used that system the calculation of a falling object was like ...