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.
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 ...
15
votes
6answers
7k views
How do I build a 2D physics engine? [closed]
The most advanced games I've made are a 8-ball pool game made with the physics engine Box2dFlashAS3 and a platform game with levels.
When I did platform games, I've always wished to know how to make ...
7
votes
1answer
376 views
How can I copy or back-calculate definitions for an entire b2World?
I'm working on a platformer where I'd like to be able to move or copy bodies between multiple Box2D b2Worlds. The desire has cropped up three times now - moving objects between documents in my editor, ...
2
votes
2answers
446 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 ...
7
votes
3answers
274 views
Impulsioned jumping
There's one thing that has been puzzling me, and that is how to implement a 'faux-impulsed' jump in a platformer. If you don't know what I'm talking about, then think of the jumps of Mario, Kirby, and ...
21
votes
6answers
2k views
Implementing a wrapping wire (like the Worms Ninja Rope) in a 2D physics engine
I've been trying out some rope-physics recently, and I've found that the "standard" solution - making a rope from a series of objects strung together with springs or joints - is unsatisfying. ...
13
votes
3answers
2k views
How do I handle moving platforms in a platform game?
I don't want to use box2d or anything, I just want simple moving platforms (up-down, left-right, diagonal and circular paths). My question is to handle the update order / control hierarchy so that the ...
29
votes
6answers
2k views
Analysis of Mario game Physics [closed]
I know there's a breakdown of Sonic the Hedgehog physics found here, and I was wondering, does there exist a breakdown of any of the Mario games? Something similar to this but for Mario is what I'm ...
9
votes
4answers
3k views
Vehicle physics with skid
How would I go about creating vehicle physics for a car that can loose traction? I want it to seem like the driver has a flat foot, so when you press the gas, they cars driving (rear) wheels loose ...
9
votes
2answers
1k views
Continuous Physics Engine's Collision Detection Techniques
I'm working on a purely continuous physics engine, and I need to choose algorithms for broad and narrow phase collision detection. "Purely continuous" means I never do intersection tests, but instead ...
7
votes
4answers
646 views
Not sure how to handle “deceleration”
I say "deceleration" because I'm not using acceleration at the moment (it is being calculated, it's just set to 0 0); what I mean is moving the velocity back towards zero, eventually stopping.
I'm ...
5
votes
4answers
4k 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 ...
8
votes
3answers
692 views
Forces on a wire in a 2D environment? (Physics)
Assume I have a physics primitive I am going to call a "wire" wrapped around a 2D environment (as described in this question).
Here's an illustration of what that might look like:
In the example ...
5
votes
4answers
492 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 ...
8
votes
1answer
566 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?
8
votes
2answers
2k views
Why use Runge Kutta Integration over Improved Euler Integration?
I was reading these slides (very good by the way!), and if you skip all the way to the end the author compares all the different integrators presented.
In one way or another, they all fall short ...
7
votes
1answer
2k 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 ...
5
votes
2answers
1k 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 ...
3
votes
5answers
1k views
Determining the angle to fire a shot when target and shooter moves, and bullet moves with shooter velocity added in
I saw this question: Predicting enemy position in order to have an object lead its target and followed the link in the answer to stack overflow. In the stack overflow page I used the 2nd answer, the ...
9
votes
3answers
1k views
How to calculate the rotation resulting from ball bounce
Hey all, still working to incorporate more physics simulation into my game (mentioned HERE). Now having the ball successfully and quite realistically bouncing a surface it hits, I wanted to make the ...
5
votes
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
...
4
votes
1answer
259 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 ...
3
votes
3answers
216 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 ...
2
votes
4answers
523 views
How to Make Objects Fall Faster in a Physics Simulation
I used the collision physics (i.e. Box2d, Physics Body Editor) and implemented onto the java code. I'm trying to make the fall speed higher according to the examples:
It falls slower if light object ...
2
votes
1answer
399 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 ...
2
votes
2answers
839 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 ...
1
vote
1answer
937 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
420 views
How can I implement fixed joints in a 2D physics system?
I'm developing a simple, 2D physics system to complement an entity/component game object framework. So far, I have implemented some basic, tutorial-level physics. An entity that is affected by physics ...
0
votes
2answers
2k views
What fluid simulation system is used in iPhone games?
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
2answers
236 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:
...
4
votes
2answers
206 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
2answers
688 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 ...
2
votes
1answer
177 views
Realistic 2D Planetary Physics Engine?
I'm doing a spaceflight simulator in C++ (using Allegro 5), and I realised that I could just use a physics engine instead of writing my own physics.
So that's what I'm doing.
Since this is going to ...
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 ...
2
votes
1answer
540 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
1answer
145 views
Swarm/crowd movement with box2d?
Apart from using b2Body::setTransform(), are there other ways to move a body around while keeping its dynamics ?
I want to move several bodies at the same time into one direction, pretty much like ...
1
vote
1answer
289 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 ...
1
vote
1answer
997 views
Making an object swing from one rope to another
I am trying to make a Tarzan like game with Cocos2D and Box2D. I am having issues with the physics - making an object swing from one rope to another. I am not really sure how to do this. Could anyone ...
1
vote
2answers
1k views
Box2D Platform body not moving player body along with it
I am creating a game using Box2D (Javascript implementation) - and I added the ability to have a static platform, that is moved along an axis as a function of a sine.
My problem is when the player ...
-4
votes
1answer
586 views
Homemaking a 2d soft body physics engine
hey so I've decided to Code my own 2D soft-body physics engine in C++ since apparently none exist and I'm starting only with a general idea/understanding on how physics work and could be simulated:
...
