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.
50
votes
5answers
15k 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 ...
29
votes
6answers
3k 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 ...
27
votes
11answers
4k 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 ...
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. ...
18
votes
7answers
2k views
Optimizing gravity calculations
I've got a bunch of objects of varying size and velocity which gravitate towards each other. On every update, I have to go over every object and add up the forces due to gravity of every other object. ...
16
votes
1answer
545 views
Recreating retro/NES style physics with intentional imprecision
Background:
I'm having a problem getting the jump curve correct for a retro platformer remake project of mine. The original game is for the NES, and the player's velocity is stored in two separate ...
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 ...
15
votes
3answers
833 views
How does one avoid the “staircase effect” in pixel art motion?
I am rendering sprites at exact pixel coordinates to avoid the blurring effect caused by antialiasing (the sprites are pixel-art and would look awful if filtered). However, since the movement of the ...
15
votes
1answer
2k views
Ideas for 2D Water Simulation
I am looking for any input on simulating water in 2D, against a rather large (call it) blocked/not blocked array (viewed from the side). I have come up with the following ideas:
Cell Automata
Do a ...
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 ...
13
votes
1answer
5k views
Quad tree vs Grid based collision detection
I'm making a 4 player co-op r-type game, and I'm about to implement the collision detection code. I've read a lot of articles and stuff about how to handle collision detection, but I'm having a hard ...
13
votes
3answers
1k 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 ...
12
votes
3answers
646 views
Resolving a collision with forces
In my 2D physics engine, I can detect AABB vs AABB collisions, and resolve them by finding the shortest penetration vector and adding it to the AABB's position.
Doing this "pushes" the first AABB ...
12
votes
3answers
2k 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 ...
11
votes
4answers
615 views
How to get object to lose less velocity as its speed increases
I'm developing a game in Flash and I need a little help. It can be considered a math problem.
My object is flying with speed X and my object can collide with stones. When it collides with a stone, I ...
11
votes
2answers
2k views
2D Planet Gravity
I'm trying to make a simple game where a spaceship is launched and then its path is effected by the gravity of planets.
Similar to this game: http://sciencenetlinks.com/interactives/gravity.html
I ...
10
votes
4answers
701 views
Player moving up, is he jumping or climbing?
In a 2D physics-based platformer game that has ladders in it, how do you determine whether the player moving up is caused by a jump or him climbing a ladder, such that you know what animation to play? ...
10
votes
4answers
2k 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 ...
9
votes
5answers
1k views
2D platformers: why make the physics dependent on the framerate?
"Super Meat Boy" is a difficult platformer that recently came out for PC, requiring exceptional control and pixel-perfect jumping. The physics code in the game is dependent on the framerate, which is ...
9
votes
1answer
2k views
Box2D Get Bounding Box of a Body
In Box2D, I was curious if it's possible to get a bounding box of a body already created in the world.
So basically, the Body is created, it's interacting with the world and such. And I needed that ...
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
1answer
1k views
Who know how to implement the 2D bone animation showed in the game?
I wonder how do they implement the bone animation in the flash game http://www.foddy.net/athletics.swf Do you know any study materials which I can start to learn 2D bone system from? I just ...
9
votes
3answers
2k 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 ...
9
votes
3answers
344 views
How to simulate pressure with particles?
I'm trying to simulate pressure with a collection of spherical particles in a Unity game I'm building. A couple notes about the problem:
The goal is to fill a constantly changing 2d space/void with ...
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 ...
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 ...
8
votes
3answers
712 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 ...
8
votes
5answers
3k views
How can I easily implement swinging in a platformer game?
I'm developing a game in which player can use ropes to swing (just like what Spiderman or Bionic Commando did) and I'm having problem implementing this behavior. Can anyone help me how to do this, I ...
8
votes
1answer
599 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
3answers
778 views
Tiling Physics using Farseer
I'm having a problem with the Farseer Physics Engine, where in a tiled environment, my object will at times interact with corners of others objects, even if they align perfectly.
You can try it ...
8
votes
1answer
208 views
Calculate bike heading from front wheel heading and velocity
I have a simple top down bike game that I'm trying to add steering to. I would like to know how I use the heading of the front wheel to determine the heading and velocity of the bike.
void Update () ...
7
votes
4answers
667 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 ...
7
votes
6answers
361 views
Determining player.isFalling() through change of y?
I'm currently using Box2D and my character is a bunch of fixtures in Box2D. I was wondering if, to determine if a player is falling, detecting a change in Y position would be appropriate?
Are there ...
7
votes
3answers
283 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 ...
7
votes
2answers
678 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 ...
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 ...
7
votes
1answer
464 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 ...
7
votes
3answers
943 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 ...
7
votes
2answers
1k views
Box 2D Set Origin
I'm trying to set the origin of a box2d shape. By default, a shape rotates around the center. But I'm trying to get it to rotate around the left of the shape. Like a clock for example.
I've heard of ...
7
votes
1answer
384 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, ...
6
votes
3answers
363 views
Smooth waypoint traversing
There are a dozen ways I could word this question, but to keep my thoughts in line, I'm phrasing it in line with my problem at hand.
So I'm creating a floating platform that I would like to be able ...
6
votes
2answers
1k views
How to calculate the exit speed of ball bouncing off a solid surface
Hey all, I am working on a simple game to include some rigid body dynamics, involving placing (moving & rotating) some springs to bounce a falling ball into a target area.
My problem is correctly ...
6
votes
2answers
640 views
How could you create climbing movement in a 2D platformer?
Basically what I want to do is have a playable character that is able to "walk" on an organic surface at any angle, including sideways and upside-down. By "organic" I mean I want my levels to have ...
6
votes
1answer
224 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
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?
...
6
votes
3answers
1k 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 ...
6
votes
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
votes
1answer
240 views
How do engines avoid “Phase Lock” (multiple objects in same location) in a Physics Engine?
Let me explain Phase Lock first: When two objects of non zero mass occupy the same space but have zero energy (no velocity).
Do they bump forever with zero velocity resolution vectors or do they ...
5
votes
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
votes
4answers
341 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 ...
