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.

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A Star pathfinding algorithm, multiple node set optimization

I'm trying to determine if this is an optimization I should pursue or if this is way to complicated to be worth my time. I've successfully implemented the A Star Algorithm for my video game. I used ...
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1answer
36 views

Numerical integration of multiple off-center forces on a solid body

I am trying to develop a little simulation (for the sake of learning a little bit about physics) involving a circle (mass m, radius r, regular density) and two forces f1, f2 that can be applied on any ...
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2answers
53 views

Speeding up sprite the second time it passes the screen [on hold]

I'm a student studying Games Development. I want a sprite to speed up on it's second passing of the screen. How do I do this? Code I wrote so far: public class Game1 : Microsoft.Xna.Framework.Game { ...
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1answer
111 views

How can I simulate a magnet that attracts a ball in a 2D enviroment?

I am making a top-down game where you have to move a ball from point A to point B. You are attracting the ball using magnets that are standing still. The ball needs to get pulled by multiple magnets. ...
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21 views

How to determine positions to draw lines on a screen with AndEngine

I have a screen (480x800), M(mx, my) is a static point, and N(nx,ny) is a dynamic point on screen. Position of N(nx, ny) depends position of touch. I want to determine position of P(?,?) and Q(?,?) to ...
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1answer
85 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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1answer
33 views

Incosistent jump, stuttering

I've written this C# code to handle movement in my testing project. The game is supposed to be 2D, some kind of a platformer, just to get me started with Unity. However, it seems there's something odd ...
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44 views

Implementing a motorized hinge joint

I have a 2d physics engine, with three boxes: "body", "left wing" and "right wing". The wing boxes are connected to the body using a hinge joint. The physics world has no gravity. I'm attempting to ...
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67 views

Ease Rotate RigidBody2D toward arbitrary angle

I'm trying to make a rigidbody2D circle return to an orientation after a collision. But there is a weird behavior I do not expect - it always orients to the same direction. This is what I call in ...
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1answer
102 views

Consistent Space Gravity Simulation

I have done some reading into this subject but haven't been able to come to a conclusion that I'm really satisfied with so far, so here is the situation. I have a game set in space, its top down and ...
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1answer
65 views

Bullet - objects falling through

I have problem with bullet collisions. You can see problem on this video (around 0:18): http://goo.gl/DiVP8l Objects are "embeded" inside vertical bars - that is not correct - they should be ...
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1answer
79 views

Determining a sensible gear-like hierarchy for a series of connected objects

I would like a series of objects to behave in similar manner to a series of connected gears. This means that each black object in the diagram below will rotate at a speed based on the ratio of their ...
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1answer
148 views

Unity WheelJoint2D will not rotate when increasing motor speed

I have a wheel joint 2D attached to a game object in Unity: In its associated wheel script I am increasing the motor speed as described in the tutorial. public class Wheel : MonoBehaviour { ...
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0answers
31 views

How to handle car game circuits in a top-down view?

I'm already using a physics engine (box2d) but i have no idea about how should I implement circuit's path with wall collision. I tought about checkpoints but this doesn't solve the wall collision.
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1answer
108 views

Spritekit - gradually apply force vector in different direction (space ship turning)

I have a space ship that I'm applying a force vector to using a joystick for control. I would like this to smoothly fly around when I'm switching directions.. Exactly like minisquadron if you've ...
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1answer
189 views

Swinging a sword in Xcode with Sprite Kit

I'm working on making an RPG in Xcode, and I'm having a major gameplay issue when it comes to having my character swing his sword in a way that is realistic and gameplay compatible. Right now, when ...
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2answers
155 views

How to detect collision on specific part of the sprite node

I have a spike and a ball is falling down, when the ball touches the top point of the spike, I want to make the ball invisible, and when it touches on the other part i.e on the sides I don't want to ...
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1answer
90 views

Best practice for organizing the physics of objects?

Apologies because this is a long post and I am inexperienced. I would really appreciate the input from some experienced developers. These are my two goals for this project: To learn the best ...
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1answer
118 views

Trajectory Projectile with Collision Detection

Right now I am trying to create projectile for cannon in which I want to detect collision also. At present I have simple working projectile after using two references Unity – How to display ...
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1answer
81 views

Frame-rate independent friction on movement in 2d game

I have been trying to implement a simple physics system for a 2D space game I am making. I have it pretty much working, but I have encountered an issue with the way I apply friction. I have tried ...
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0answers
43 views

Box2D collision damage calculation from postSolve or not?

I'm using postSolve to get impulse then calculate damage base on that impulse. But there's some issue: Stability The damage isn't stable. When the same ball is hitting with same speed, the damage ...
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2answers
105 views

How to Calculate Velocity in a 2D space game

I am currently using screenpos.X = (float)(screenpos.X + velocity * Math.Sin(r)); screenpos.Y = (float)(screenpos.Y - velocity * Math.Cos(r)); For my Movement with r being the Rotation in Radians. ...
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50 views

Particle friction with variable timestep in XNA

Alright, so I'm working on an engine of sorts in XNA (yes, it's deprecated, I know) and I'm implementing my own particle system. I've defined a "ParticleEffect" such that when it's supplied a GameTime ...
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1answer
139 views

Inverse Explosion with Unity2d

I am currently trying to make all other objects push away from the player when the player explodes. It currently works, but it pushes close objects a little and far objects very far. What I want is ...
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1answer
101 views

Resolution independent physics

I'm making a game like Doodlejump but don't know how to make the physics scale on multiple resolutions. I also can't find anything related to this on Google. Right now I'm scaling the game using ...
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1answer
67 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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2answers
179 views

How can I make an object's hitbox rotate with its texture?

In XNA, when you have a rectangular sprite that doesnt rotate, it's easy to get its four corners to make a hitbox. However, when you do a rotation, the points get moved and I assume there is some kind ...
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1answer
108 views

Bouncing ball slowing down over time

I use the unreal engine 4 to bounce a ball off of walls in a 2D space, but over time the ball gets slower and slower. Movement happens in the tick function of the ball FVector location = ...
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2answers
128 views

Sprite Kit - containsPoint for SKPhysicsBody?

I have a ball bouncing around the screen. I can pick it up and drag it onto a "bucket". When my touches finish, I use the containsPoint function to check and see if I have dropped the ball onto the ...
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1answer
95 views

simple collision detection with box2dweb

im beginner in box2dweb that version of box2d for javascript i wrote simple gravity system and i want to detect the collision between the box and the ground , when the falling box hit the ground ...
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1answer
85 views

Can I have a fixed-angle sprite with a non-fixed-angle CircleCollider2D?

In Unity2D, can I have a fixed-angle sprite with a non-fixed-angle CircleCollider2D? I would like to move my character using the circle physics (without fixed-angle), but display him always as if he ...
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0answers
34 views

Box2d not showing consistent behaviour with sprites

Box2D newbb here. My question is in regards to this create js project:http://mboyeman.com/dashingdog/ (runs best in IE...:3) I wrote a function(assignBlockBodies) to give 2D Edges to sprites based on ...
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2answers
444 views

How to circle a target at a constant distance

I have an AI ship that stops approaching when it gets within firing range, and starts strafing around its target. The problem is that it doesn't circle its target very well. The following code ...
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2answers
264 views

Platformer Collision Detection Order

I'm attempting to create a 2D Platformer Game and I'm having difficulty with the physics I have implemented. Each loop my code does the following: Apply the physics to a temporary X and Y ...
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1answer
113 views

Mixing interpolation with extrapolation in multiplayer game

I am creating a multiplayer drag racing game and have difficulties mixing extrapolation and interpolation. To save network bandwidth i am getting information from the opponent only on his button ...
2
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1answer
127 views

2D physics rotation w/ XNA

I'm creating a simple game with space ships made of blocks that are all the same size. After having looked at this: Calculating the rotational force of a 2D sprite I have created the following code ...
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2answers
120 views

How do I implement friction in a billiards game?

I'm having trouble implementing friction in a billiards game. Currently, the ball only slows on collision with the edges, but I also want some friction with the background. How can I implement ...
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2answers
50 views

Custom Physics: Preventing objects from losing velocity in certain situation

Illustration: http://s22.postimg.org/7agd30vap/Untitled.png So the little box is my character. The red arrow shows the current velocity(Some force to right + gravity). Below it are 2 blocks which has ...
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0answers
63 views

Storing rigid body collision shapes in local or world coordinates

I'm writing the beginnings of a lightweight 2d rigid body engine (in javascript, as a hobby project), and i'm debating whether to store collision shapes in local or in (updated as needed) world ...
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1answer
96 views

Mobile: Physics and movement actions

I've been using spritekit for a while for a few small games. One thing I've noticed is that spritekit is the first game framework I've used that allows me to apply move actions to physics bodies. ...
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2answers
106 views

How to know when all 2d rigid bodies have stopped in unity3d?

Is there anyway to know if all 2d rigid bodies in untiy 3d phisics world have stopped?
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102 views

Moving objects smoothly, bad perfomance

I just finished developing my mini-game on Android and I got some questions about perfomance and generally "how to": If I have 25+ objects on the creeen (just a polygon with 7-8 angles) its starts to ...
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1answer
127 views

How do I convert a partially transparent image into polygons?

I'm using GLEE2D, a level editor allowing me to import images, scale them, rotate them, and position them onto layers and export the data into XML format. However, it does not tell me objects' ...
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1answer
42 views

How to predict physics movement [duplicate]

How to predict the movement of the body when a force is applied on it like in the https://play.google.com/store/apps/details?id=com.game.basketballshoot I have attached screen shot as reference.
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107 views

How to find correct offset to adjust sprite to the position of box2D body after rotation

I am trying to implement phsyics with the as3 box2d port. I currently have a b2body for each of some certain sprites in my game and I am able to update the sprite's positions correctly from the ...
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0answers
44 views

Apply impulse to ball to a fixed height Jbox2D android

I have to hit a ball to a fixed height repeatedly as shown in the following image. This game is similar to 1983 Hitit The difference is the hitting y axis will be variable. I wanted to hit the ...
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0answers
19 views

Artificial physics : ball angle bouncing (Vector2) [duplicate]

My question is : how can I manage to move my object (ball) on a trajectory , and onContact with another object, it bounces, respecting the angle
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1answer
499 views

Movement and rotation of bodies in top down game

We are developing a 2D top down game with libgdx using the included box2d as physics engine. We don't want our bodies to accelerate but to instantly move with the wanted velocity. The bodies are ...
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1answer
81 views

Calculating the point(s) at which two moving objects are a certain distance from each other

Problem This is similar to a Closest Point of Approach calculation, but instead of the closest point(s), I want the points at which the objects are a given distance away from each other. (Imagine two ...
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1answer
126 views

Calculate point of circle–circle collision between frames

I need to find the exact XY coordinate where a circle collides with another circle calculated between frames. This means that I take the coordinate of the moving circle on the previous frame and take ...