Tagged Questions

-1
votes
1answer
99 views

“Car” movement in 2D dimension [closed]

I am searching for a simple tutorial how to add arcade car physics for my game. Exactly same user units behaviour i found in next games: Tank Hero: Laser Wars Death Worm: Video: ...
0
votes
3answers
134 views

Gravity independent of game updates per second

Edit Just for clarification, my sprite's 'movement' isn't the problem. If I set my Time variable to 4 seconds, then it will cross the screen in exactly 4 seconds regardless of logic updates rate per ...
4
votes
3answers
154 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 ...
1
vote
1answer
147 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 ...
2
votes
1answer
181 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 ...
3
votes
1answer
187 views

Fluid Particle Grid

So recently I have been looking at some fluid simulation techniques, specifically Smoothed Particle Hydrodynamics. One of the key components is a grid to avoid O(n^2) searches. I have been having some ...
0
votes
2answers
74 views

Problem with sensor in box2d [closed]

I have two bodies: one green static sensor (spikes) and one orange dynamic body (brick). I have bullet and it's a dynamic body too, but with bullet flag set. My problem is that when the bullet is ...
0
votes
2answers
65 views

Checking bounds of a quad

I want to know how would I tell if a quad touches another quad in my game built in Slick2D. I have a class that I named "Bounds" which has 4 "Point" objects which just store an X and a Y value and a ...
1
vote
2answers
128 views

Distribute circles evenly on Screen - circle packing

I want to evenly distribute a random amount of circles with random diameter on the screen for. This level doesn't scroll so the users screen resolution sets the limits. Further I would like the ...
2
votes
1answer
99 views

Physics movement prediction is way off [closed]

I'm making a simple, non-networked game. There are two players and a ball. In implementing the AI for the second player, I've run into a huge problem predicting where the ball will hit the ground. ...
12
votes
3answers
611 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 ...
4
votes
2answers
238 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: ...
-2
votes
1answer
105 views

Help finding a good XNA physics library? [closed]

I'm looking for a good physics library for XNA. Can anyone help me find something good, simple and easy to learn for XNA?
2
votes
1answer
166 views

RK4 integration and Continuous Collision Detection

I'm using this method to detect collision between two AABBs. The algorithm is simple, fast and works great. It uses the relative velocity between the two objects to calculate TOI. This works fine with ...
8
votes
1answer
203 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 () ...
5
votes
1answer
132 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 ...
6
votes
1answer
236 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 ...
7
votes
3answers
277 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 ...
2
votes
4answers
532 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
2answers
210 views

Procedural generation of physics-enabled structures (in a 2D world)

Is it possible to procedurally generate stable structures out of rigidbody objects at a reasonable runtime speed? Imagine Angry Birds's levels kind of structures but generated procedurally.
1
vote
1answer
104 views

What is going on in this SAT/vector projection code?

I'm looking at the example XNA SAT collision code presented here: http://www.xnadevelopment.com/tutorials/rotatedrectanglecollisions/rotatedrectanglecollisions.shtml See the following code: private ...
1
vote
3answers
162 views

Implementing distance joint

I would like to implement something that behaves much like a distance joint / revolute joint in Box2D, however I do not want to throw a whole physics engine at this problem. I'm curious where I might ...
4
votes
4answers
475 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 ...
0
votes
1answer
155 views

Game Physics: Implementing Normal Reaction from ground correctly

I am implementing a simple side scrolling platform game. I am using the following strategy while coding the physics: Gravity constantly acts on the character. When the character is touching the ...
5
votes
3answers
309 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 ...
2
votes
0answers
228 views

Nape physics - Moving a body

Hey I'm currently getting started with physics engines and I set up a body (box shaped) which represents my character. Question: Which methods can I use to move a Nape.Body aka my char? I tried so ...
0
votes
2answers
345 views

Circle physics and collision using vectors

This is a problem I've been having, When making a set number of filled circles at random locations on a JPanel and applying a gravity (a negative change in the y), each of the circles collide. I want ...
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 ...
6
votes
3answers
358 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 ...
2
votes
1answer
408 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
votes
1answer
261 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 ...
1
vote
1answer
143 views

2D Physics Engine to Handle Shapes Composed of Multiple Densities XNA

The game I'm working on involves shapes that might be composed of multiple materials in a variety of ways. Let's just take for example a wooden rod with and sizable tip of iron or say a block composed ...
2
votes
1answer
281 views

android game-logic for shooter

Im creating a 2d game for android. I'll just get right to it. I have a sprite controlled by a joystick that needs to shoot, sofar Ive managed to get direction and movement on my bullet, but then I ...
1
vote
1answer
166 views

Stopping an object after applying an impulse or force?

I'm having a small issue where after applying an impulse or force it is impossible to actually get an object to stop, i.e. a velocity of zero. This code is run every 1 / 60 of a second: void ...
8
votes
1answer
574 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?
3
votes
1answer
269 views

How to bounce a 2d point particle off of a circular edge

In a prototype I'm building, a particle can spawn anywhere within a larger, confining circle. Important to note is that the particle will not spawn in the origin of the larger circle, but anywhere ...
9
votes
3answers
340 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 ...
7
votes
2answers
652 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 ...
0
votes
1answer
356 views

Specific Physics Lessons and Reference for Game Development

What "Physics stuffs" should I learn in game developments? I'm reading about Verlet Integration, and I'm wondering what other lesson should I learn and if there are available resources can you please ...
1
vote
1answer
446 views

Box2D platformer movement. Should i mess with velocity?

I have a platformer game in which I implemented the movement using a wheel attached to the hero. For jumping I use this: player.body.applyLinearImpulse(new Vec2(0, 30000000), ...
0
votes
1answer
534 views

JBox2D applyLinearImpulse doesn't work

So i have this line of code: if(input.isKeyDown(Input.KEY_W)&&canJump()) { body.applyLinearImpulse(new Vec2(0, 30), cam.screenToWorld(body.getPosition())); ...
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 ...
0
votes
1answer
687 views

Ball Physics for Android Game

I am starting work on a new Android game and I haven't had any experience implementing physics before. I am trying to steer clear of external libraries such as box2d, not just because I think it is ...
5
votes
3answers
5k views

2D character controller in unity (trying to get old-school platformers back)

This days I'm trying to create a 2D character controller with unity (using phisics). I'm fairly new to physic engines and it is really hard to get the control feel I'm looking for. I would be really ...
0
votes
2answers
484 views

Ways to define a curve

I'm trying to give shapes in my physics engine roundness/ curvature. I am aware of various methods for mathematically defining curves; such as bezier-cruves, ellipses, etc. However I am not sure ...
2
votes
2answers
437 views

Physics in carrom like game using cocos2d + Box2D

I am working on carrom like game using cocos2d + Box2D. I set world gravity(0,0), want gravity in z-axis. I set following values for coin and striker body: Coin body (circle with radius - ...
3
votes
4answers
328 views

Collision filtering techniques

I was wondering what efficient techniques are out there for mapping collision filtering between various bodies, sub-bodies, and so forth. I'm working on a physics engine and I need ways for a user to ...
1
vote
3answers
388 views

Axis-Aligned Bounding Boxes vs Bounding Ellipse

Why is it that most, if not all collision detection algorithms today require each body to have an AABB for the use in the broad phase only? It seems to me like simply placing a circle at the body's ...
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 ...
1
vote
1answer
540 views

Game Physics With RK4 Implementation For A 2D Platformer

I been reading about RK4 for physics implementation in a game, so I read in some pages and all people recommend me this page: http://gafferongames.com/game-physics/fix-your-timestep/ This page shows ...

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