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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collision resolve sphere-aabb and aabb-aabb [closed]

I am currently working on a basic physics engine which does not consider rotations. At the moment I work on collision resolving between aabbs and spheres. Unfortunately I have no idea what a collision ...
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1answer
153 views

Anybody remember this webpage? [closed]

I remember visiting a webpage some time ago (1 year ago maybe) It contained many java applets, describing how certain mathematical functions like sin, cos, arcsin, exp would make an object move, with ...
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707 views

Variable physics step, bad idea?

Currently, when I update the entities I calculate the time passed since the last update, and then pass that to their update function. They will in turn pass that duration to all their components. ...
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2k views

Collision Detection for 2D

I am working on a simple game, where I need to do a collision detection of two Texture2D. The code I have written is: bool perPixelCollission = false; Texture2D texture1 = sprite1.Texture;...
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43 views

2D circle against a corner change in direction

I have a 2D Ball that might go against a wall. If the Ball goes against the wall perpendicularly, it will just invert its direction (assuming no air resistance and no bounces that should make its ...
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1answer
82 views

2D sunrise in Unity

I see a lot of guides on how to create sunrise in 3D space, but I can't find much information on how to do it in 2D. In 3D, you rotate a lightsource around itself, but in 2D, I need to move the object ...
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97 views

Acceleration problems

Im trying to make a car game, but i cannot get the acceleration code right. With this code: if(gas){ speed += 3; }else if(break_ && !(speed < 6)){ speed -= 3; ...
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504 views

Testing Unity 2D Physics

I am looking to push the 2D physics in Unity to the extent where when so much is going on that there becomes noticeable lag in a game. This is for testing purposes, so that when so much is going on ...
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305 views

Simulation of ball movement in a 3d landscape. The easiest way?

I have a landscape(generated via Perlin noise) and a ball. I want the ball to move along the geodesic(implementation of basic physics: gravitation, friction). I thought to do raycast around the ball ...
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351 views

Estimate the time it takes for an object to travel from point A to point B

I have an object with vec2 position, velocity, and destination with 2 variables maxspeed and acceleration. In each step, its position is calculated as follows: vec2 desiredVel = destination - ...
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32k views

Simple collision detection in Unity 2D

I realise other posts exist with this topic yet none have gone into enough detail for me. I am attempting to create a 2D game in Unity using C# as my scripting language. Basically I have two objects, ...
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256 views

AABB vs Rectangle

I'm trying to wrap my head around 2D physics and stumbled upon Axis Aligned Bounding Boxes, and I have a couple of questions regarding them. In all AABB structs I could find out there, people prefer ...
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106 views

Box2D relations

As far as I know, the unit in Box2D is meters. When I use Box2D in Processing with JBox2D, I set the "world size" as the window size specified in the setup(). Now I'm wondering if there is any ...
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104 views

How to reduce the time it takes to speed up an object?

I have a body that I am applying a force to every step. However, I it takes a significant amount of time for it to speed up, which I do not want. Is there some value I can adjust to help with this?
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How to move around a player in a curved tunnel?

In a scenario where the player moves freely along the walls of a tunnel (like this), what is the best way to move the player along the walls of the tunnel? I'm using Unity3d game engine. I've tried ...
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1answer
1k views

Box2d contant speed before and after collision

I want to make my body fly at constant speed, how to make it fly at constant speed before and after collision? I set restitution of my body to 1.0 but after some direct and powerful collisions my ...
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291 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 ...
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437 views

How can I manage large numbers of objects in a physics engine? [duplicate]

MY friend and I are programming a game and I decided to give the physics engine a try. I was able to get a class working where it would calculate out the total force on a model and apply the correct ...
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219 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 ...
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2answers
199 views

Collision detection for Monotouch [closed]

What I want to have for my Monotouch 2D projects: simple collision detection and collision polygons working with UIViews Sounds simple, isn't it? I've evaluated a lot of engines available on the ...
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378 views

What different ways are there to model restitution in a physics engine?

In my physics engine I give a body a value for restitution between 0 and 1. When two bodies collide there seems to be different views on how the restitution of the collision should be calculated. To ...
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1k views

Calculating angle between two vectors to steer towards a target

I have been trying to implement a path following steering behaviour for AI in a 2D racing game. I have two vectors: futurePosition represents the predicted future position given the car's current ...
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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 ...
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341 views

Calculating the force of an impact?

I'm trying to figure out a way to determine the force two objects collide in. I have two vectors defining their linear velocity at the time of impact, their mass and their angular velocity. Keep in ...
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What is a good practice for deciding when to use transforms instead of applying force?

I was making several games. I don't understand when I should use addTorque instead of rotate. AddForce instead of position The latest game was a pinball game. I wasn't sure the best way to active ...
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1answer
38 views

Gravity wells that go with finger [duplicate]

I have a simple particle game, where all the particles are arranged in a grid. This game is for touch devices so to take advantage of it I am trying to have a multitouch gravity field thing going on. ...
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3answers
2k views

Invalid AABB aabb

Invalid AABB aabb UnityEditorInternal.InternalEditorUtility:CalculateSelectionBounds(Boolean, Boolean) I've got this error ...
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160 views

LOVE Physics - Breaking Joint Chains (LUA / Box2D)

Wasn't sure whether to post here or on SO so please move if needed. I've been having a look into the box2D physics API provided by LOVE to try and create a swinging flail or weighted rope but I'm ...
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147 views

Calculate intersect point / aim point

I'm working on a simple game, and I need to calculate the position to aim. Since my math days are a bit behind me, I put together a simple example to illustrate: So given that I know the position ...
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432 views

Leapfrog integration vs Euler integrator

I am looking at various integration methods for my n-body simulation and I'm slightly confused about actual implementation of leapfrog integration. According to the wikipedia page leapfrog method is ...
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1answer
129 views

What is the purpose of integration in physics engines?

All online resources seem to assume that you know what this means and/or state that this is related to object movement in some way. How does this differ than just position.x++ and position.y++ and ...
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1answer
315 views

Wandering motion in Unity

I am trying to come up with a smooth wandering motion for my game-object using Unity. What I currently doing is rotate the object by some random angle calculated every 1.5 second delay. But I am ...
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1answer
95 views

Reflection velocity

I'm trying to get a moving circular object to bounce (elastically) off of an immovable circular object. Am I doing this right? (The results look right, but I hate to trust that alone, and I can't ...
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617 views

How can I get the force of a collision in Love2D?

Is it possible to get the force of a collision between two objects in Love2D/Box2D? If so, how?
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76 views

Controls: Rolling on a ceiling

Currently I'm writing an iOS game where the basic movement is rolling. Technically you make the player turn clockwise or counterclockwise. When you tilt the device to the right, you will rotate ...
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1answer
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Need to translate a Rotation Matrix to Rotation y, x, z OpenGL & Jitter for 3D Game

I am using the Jitter Physics engine which gives a rotation matrix: M11 M12 M13 M21 M22 M23 M21 M32 M33 And I need it so OpenGL can use it for rotation GL.Rotate(xr, 1, 0, 0) GL.Rotate(yr, 0, 1, 0)...
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650 views

How should I invoke a physics engine?

I'm new to writing games. I'm planning to write a 2D battle game which may require an physics engine. Suppose I've written one, but how can I combine it with the main routine of my game? Should I ...
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1answer
739 views

Making Ball Fling in a Curve Direction

I was wondering how to figuring out how to slice a ball (banana kick) by flinging it curve-ways. However, according to the LibGDX's gesture listener, the method for flinging only focuses on a straight ...
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163 views

Moving Sprite With Physics Frame

Normally, a physics frame in pink (see image below) gives the body for detecting hit signal. It usually either falls down or lifts up depending on the gravity orientation. The question is: Is it ...
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1answer
182 views

Increase restitution (bounciness) of an object in a JavaScript formula

I'm going slightly around the houses on this one. I originally started a thread over on Stack Overflow about it but then it seemed to diverge into mathematics, with no joy from the SO community over ...
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469 views

When and where should I calculate collision response with multiplayer physics?

I've troubles wrapping my head around multiplayer physics and collisions on the client side, so far I interpolate the state of my network entities ( position and velocity ) of the other clients based ...
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297 views

Numerical stability in continuous physics simulation [closed]

Pretty much all of the game development I have been involved with runs afoul of simulating a physical world in discrete time steps. This is of course very simple, but hardly elegant (not to mention ...
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632 views

How do 2D physics engines solve the problem of resolving collisions along tiled walls/floors in non-grid-based worlds?

I've been working on implementing my SAT algorithm which has been coming along well, but I've found that I'm at a wall when it comes to its actual use. There are plenty of questions regarding this ...
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1answer
223 views

Who should respond to collision: Unit or projectile?

In an RTS if a projectile hits a unit. Who should handle the collision? If projectile handles the collision, it must be aware of all possible types of units, to know what damage to inflict. For ...
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1answer
2k views

2D OBB collision detection, resolving collisions?

I currently use OBBs and I have a vehicle that is a rigid body and some buildings. Here is my update() private void update() { camera.setPosition((vehicle.getPosition().x * camera.getScale()) - ...
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248 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 ...
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1answer
664 views

Rotating a cube using jBullet collisions

How would one go about rotating/flipping a cube with the physics of jBullet? Here is my Draw method for my cube object: public void Draw() { // center point posX, posY, posZ float ...
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1answer
965 views

Farseer Physics for Xna missing ConvertUnits class

Im using Farseer Physics with Xna 4.0. Im following a starter guide. It said that to draw, I need to convert the meters to pixels with the ConvertUnits namespace. I looked through all of the engine, ...
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How do I determine which side of the player has collided with an object?

I have some static bodies (platforms) and a dynamic body (the player) in my world. The collision between them works great, but I would like to know which side of the player (rectangle) collides with ...
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566 views

2D Physics in a networked game (iOS)?

I am researching the possibilities for a new iOS game. It's going to be a run-n-gun type platformer, and I'm looking into the possibility of co-op multiplayer. The game itself wouldn't be very ...