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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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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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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290 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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429 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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218 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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365 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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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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340 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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1k views

Invalid AABB aabb

Invalid AABB aabb UnityEditorInternal.InternalEditorUtility:CalculateSelectionBounds(Boolean, Boolean) I've got this error ...
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143 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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142 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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359 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
128 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
297 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
92 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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586 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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75 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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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, ...
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619 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
705 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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2answers
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
179 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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435 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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1answer
293 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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1answer
617 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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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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1answer
244 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
649 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
960 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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2answers
1k views

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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548 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 ...
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560 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 ...
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689 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), ...
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1answer
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Can you help with collision detection and response in a 3D car racing game?

I am trying to implement the collision detection and response in 3D car racing game. I have a car model, for collision I am assuming my car as a cuboid. my collision detection with walls is quite ...
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1answer
113 views

Synchronizing players and game objects in a server/client multiplyer game

OK guys, I have some experience with 2D game development (single player only), so that's fine no questions here. The problem is with multiplayer games. I already read lots of other questions and ...
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1answer
96 views

Bullet Physics / OpenGL Meshes Not Colliding

This is for a school project, and I'm having a bit of trouble with Bullet acting strangely. I have an OpenGL project with Bullet Physics library working with Assimp model loaders and Magick++ ...
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1answer
60 views

In Physijs, how do I detect that an object is still?

I have a cylinder that simulates a flipping coin. I am using Physijs. The coin might bounce off the surface multiple times before stopping. How can I know when the coin has completely stopped moving?
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1answer
77 views

Box2d jetski on water

At the moment I am trying to code a 2d game in java, where a jetski is riding on water. If you press on the screen the jetski should dive down and jump back up on release. How do I have to do this in ...
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1answer
240 views

How do I make circles bounce off each other realistically?

I'm trying to create bouncing balls with realistic physics. At the moment, when the balls hit each other, they bounce back in the same direction they came from. How do I make them more realistic? I ...
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2answers
189 views

Circle-Circle collision resolution

This seems easy but I can't figure it out, when I have one circle(c1) collide with another(c2) I give the c2 circle the heading of c1 and send the c1 circle on the normal vector to the heading (the ...
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83 views

Gravity Simulation failing at short distances

I have a 2D space simulation with gravity acting on three bodies (e.g. sun and 2x planets). The simulation seems pretty stable with RK4 (was unstable with Euler). The problem arises if the orbit of ...
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3answers
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Unity rigidbody2d.velocity jumping causes weird bouncing

Im working on a game 2d game that has some platforming. I followed this video as guidance and produced the following code: public class PlayerControler : MonoBehaviour public float ...
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317 views

Framerate dependent movement

I'm moving my character controller using Euler integration like this: Vector3 originalPos = transform.position; Vector3 acceleration = Physics.gravity; velocity += acceleration * Time.deltaTime; ...
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1answer
127 views

Downsides of using this integration formula for movement?

So I read that Gaffron integration basics tutorial and noticed how the Euler integration method gives a small error over time. I implemented the RK4 and noticed that with constant acceleration, I ...
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1answer
3k views

Unity 2D, C# - Make object move diagonally by a certain angle?

I have a sprite object which I want to move in 8 directions. Left, Right, Up, Down, Left top, Right top, Left down, Right down. The view is 2D with a isometric projection. The difficulties I am ...
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187 views

Is Physics a prerequisite to learn Unity3D

I have got a basic knowledge about the Unity 3D platform but I coding in Unity has not been that easy for me. For the simple reason I can see is, I cannot understand which function to use for what ...
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41 views

Forces on entities: remove all each update step, or remove on demand?

Following the answer to my question here, the way I apply forces on an entity, is each entity has a Map of forces (Vectors) and their IDs. Every update step, the acceleration vector is set to the sum ...