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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Should I write my own physics engine, because of networking integration?

I'm currently developing a top down, realtime, zombie shooter. I'm coding this in Java, using JBox2D as my physics engine. I have been coding the networking this week, and am now up to the physics ...
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0answers
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Creating Rope Physics for Unity [closed]

I want to create a bungee jumping-like game in Unity and therefore I need a rope physics. I especially need elastic ropes with capability to pull objects with velocity after a little extension. Do you ...
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4answers
2k views

How do fluid dynamics work?

How would I go about implementing fluid dynamics in a game, such as can be seen in this video?
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3answers
762 views

Random map generation - strategies for scattering/clustering random nodes

I am doing a simple 4X strategy game in space where each node is a point-of-interest (a planet, an asteroid and etc.). To randomly generate a map, I would follow the steps below Decide how many ...
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3answers
493 views

How to implement collision detection of portals?

For example, take this scenario (excuse my horrible drawing skills): This is based on "Portal", where the stickman is going through the blue portal (which is linked to the red portal), but there is ...
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4answers
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When should I use a physics engine?

Since I found out Box2D, I'm using it for kind of any game-like application I try to write, from very small prototypes or small programs to test something, to actual projects. Thanks to it it's so ...
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4answers
709 views

Run a physics simulation on both client and server?

I'm implementing a multiplayer asteroids clone to learn about client/server network architecture in games. I have spent time reading GafferOnGames and Valve's publications on their client/server ...
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1answer
748 views

How does pixeljunk shooter simulate its liquids?

I am really impressed by the liquids in pixeljunk shooter. I would love to know how they do it.
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6k 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 ...
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1answer
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Angle of Reflection

I have this "Breakeout style" game. I have a cannon at the center, blocks around the cannon and pads around the blocks. This is how the game looks like: I've managed to get the collision per ...
10
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3answers
430 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 ...
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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 ...
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3answers
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How to calculate falling and accelerating velocity?

I'm thinking of making a lander game, where you control a spaceship and need to land it without crashing. What is a simple formula to calculate speed of falling or acceleration with relation to ...
9
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1answer
388 views

Getting a 2D “pixel” cloud to follow a mouse

I'm working on a 2D game trying to get a "cloud" of a few hundred tiny cubes or discs to follow my mouse cursor without overlapping each other. However, using the physics engine introduces ...
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4answers
4k views

2D Spatial partitioning alternatives to spatial hashes and quadtrees

I've been trying to implement a spatial partitioning algorithm in my game, but both spatial hashes and quadtrees aren't what I'm looking for. My level size is not supposed to have a limit (only Int32 ...
9
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3answers
573 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 ...
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2answers
1k 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 ...
9
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1answer
329 views

Multiplayer platformer - Are server corrections normally required with a single client on the server?

I am currently working on a rather simple multiplayer platformer. I read quite a bit of articles on the techniques used to hide latency, but I still fail to get my head around certain of the concepts. ...
9
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1answer
1k 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 ...
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2answers
1k 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 ...
9
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1answer
368 views

Deforming surfaces

I try to accomplish an deforming physic behaviour for levelsurfaces, but don't get an idea how to start with the implemenation so far. Regardless of the shape from the surface (planes, cubes, ...
9
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1answer
2k 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 ...
9
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1answer
164 views

What would be a good filter to create 'magnetic deformers' from a depth map?

In my project, I am creating a system for deforming a highly detailed mesh (clothing) so that it 'fits' a convex mesh. To do this I use depth maps of the item and the 'hull' to determine at what point ...
8
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6answers
639 views

Ragdoll on alive creatures: has somebody already implemented it?

I find that a dead creature falling realistically is boring. I wonder, has any game implemented an animation system where the model moves depending of the muscle forces and the velocity of the limbs, ...
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5answers
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How do I detect the direction of 2D rectangular object collisions?

After this question, I need some more help. How can I find out which side of a rectangle a collision came from and react accordingly? The blue arrows are the paths that some circular objects ...
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4answers
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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 ...
8
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3answers
895 views

Are collision detection always O(n^2)?

Are physics engine able to decrease that complexity, for example by grouping objects who are near each other and check for collisions inside this group instead of against all objects ? (for example, ...
8
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1answer
752 views

OpenGL vs physics?

I am very new to game programming and I am in my first project. I have come to a point that I need expert advice: Now for the game physics to be able to work on objects, it needs to know each ...
8
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1answer
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How to handle physics of moving platforms in a platformer?

So after a few hours of searching on the internet, I have yet to find a pleasing answer on how to handle moving platforms in a 2d platform game. So I decided to make a simple prototype where you ...
8
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1answer
604 views

Projected trajectory of a vehicle?

In the game I am developing, I have to calculate if my vehicle (1) which in the example is travelling north with a speed V, can reach its target (2). The example depict the problem from atop: There ...
8
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3answers
946 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
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1answer
1k 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?
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2answers
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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 ...
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3answers
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Calculation of Inertia Tensors

Bit of a complex and lengthy question that, I'll admit, I don't quite understand very well yet so I will try and explain as best as I can. Short Version: Is there a general c++/physx formula out ...
8
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1answer
705 views

Are there well-known algorithms for fitting a polygon to an arbitrary shape?

I'm using the Chipmunk physics engine to make the levels for a 2D C game. I'd like to be able to fit a polygon to an arbitrary shape to serve as the collision mask. Given a black and white collision ...
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3answers
582 views

Can I jump from A to B?

I'm making some rudimentary AI for my side-scroller and I need to know whether an AI unit can reach point B from point A simply by taking a jump. Flight trajectory of my characters is a bit unusal as ...
8
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2answers
387 views

Drone targeting

Imagine a "drone" and a target point on a 2d plane. There are eight parameters: P = my position Q = target position V = my velocity I = my moment of inertia w = my angular velocity s = my angular ...
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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 ...
8
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1answer
272 views

How do I fix objects “popping” or jittering in physics engine?

I've got a simple physics engine that solves collisions by simply correcting the position of overlapping bodies (just circles for now) directly, as opposed to just changing the velocity or applying an ...
8
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1answer
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Realistic slow-falling snow algorithm?

Is there a good algorithm that simulates falling snow? I'm particularly interested in snow that falls slowly, so it doesn't quite fall in a straight line but deviates a bit. Maybe even including ...
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3answers
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How do you do AI path following within a 2d physics engine like farseer/box2d?

I'm in the process of moving a 2d top down game I've been working on into a proper rigid body physics engine like Farseer. Up until now, I had just hacked together my own physics code where needed. ...
8
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1answer
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What are the common character animation techniques used in tile based hack&slash games?

I wonder what kind of animation techniques are used for creature and character animation in modern hack&slash type tile based games? Keyframing for different actions may be one option. Skeletal ...
8
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1answer
290 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 () ...
8
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3answers
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Web workers for HTML5 game physics simulation?

A bit related to this question. The idea is to guarantee the same physics behavior as much as possible. Would it be possible to run fixed time step physics on a web worker? The UI would update ...
8
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3answers
346 views

Make fast thing look slow (Box2D)

I'm working on a game that you control a trebuchet to throw balls to the opponent. It's like a game called 'Medieval Siege'. When the trebuchet is swinging its arm, player need to seize the best ...
8
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2answers
1k views

Physics engine that can handle multiple attractors?

I'm putting together a game that will be played mostly with three dimensional gravity. By that I mean multiple planets/stars/moons behaving realistically, and path plotting and path prediction in the ...
8
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3answers
314 views

Connecting physics simulations with different coordinate-systems

I want objects to move between two physics simulations through a "window" and collide with those from both simulations in case they intersect the window plane. The coordinate systems of the ...
7
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5answers
739 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 ...
7
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2answers
3k views

Is it worth it to use Bullet for 2D physics instead of Box2D for the sake of learning Bullet?

There isn't much more to the question. I'm not concerned about overhead, as I'm sure they are both fine for my purposes. Basically, I am familiar with Box2D concepts because of the Farseer Physics ...
7
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6answers
619 views

Physics library internals

I've seen box2d and bullet ports into javascript, but neither of them attracted me particularly, except by source code. It all seemed, after all, quite simple once I looked inside them. But what are ...