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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2
votes
2answers
276 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 ...
5
votes
1answer
2k views

Unity falling body pendulum behaviour

I wonder if someone could provide some guidance. Im attempting to create a pendulum like behaviour in 2D space in Unity without using a hinge joint. Essentially I want to affect a falling body to ...
35
votes
3answers
8k views

Why do we use the Pythagorean theorem in game physics?

I've recently learned that we use Pythagorean theorem a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't ...
-1
votes
1answer
333 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 ...
4
votes
2answers
1k views

Why isn't this physics code scaling velocities separately?

I'm working my way through this book and I'm trying to work this code out: var squaredVelocity = this.velocity.x*this.velocity.x + this.velocity.z*this.velocity.z; if ...
0
votes
1answer
159 views

Making particles accelerate toward a mouse point

I'm currently working on a particle simulation program that makes pixels move towards a mouse point continually accelerating, but i'm running into some math issues. Currently my particle will ...
0
votes
1answer
391 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 ...
2
votes
1answer
262 views

Spaceship acceleration for following waypoints

I'm creating a turn based space ship strategy game with simultaneous turn resolution similar to Steam Birds. After all the orders are given, the ships run through a real time simulation where they ...
22
votes
6answers
2k views

How can I Intercept object with a circular motion

I am creating a 2d space game and need to make the spaceship intercept a planet. I have working code for straight line intercepts but cannot figure out how to calculate the planets location in a ...
1
vote
2answers
455 views

Unity - Across the wall

I have a problem here. I animated my main character and is working. It walks run and jump however it goes across walls and ground. As in every single video I watch in unity tutorials I put a ...
6
votes
1answer
504 views

How do I make a slot car game?

I new to game development with Unity and my first project is a slot car racer. For a realistic slot car-like-driving experience, I first build a track with a channel in the track and a pin on the car. ...
3
votes
3answers
389 views

Throwing a ball and estimating its path using a Physics engine

The problem: A player entity wishes to throw a ball from a known position with a known initial velocity. The surrounding environment contains physical objects that can alter the trajectory of the ...
1
vote
1answer
52 views

How to convert strict limit in position into gradual slow down?

The player moves a spell object, the spell must stay withing a certain range of the player. The spell is moved using a physics system and it has mass and velocity. Currently when the spell goes out ...
0
votes
2answers
1k views

Libgdx: movement of scrolling background is not smooth even at 60fps

I'm developing a game and I want to make a sliding background. The background is not scrolling smoothly. I logged the fps, but it was ok. This is my code, I don't know what I'm doing wrong, any ideas? ...
1
vote
0answers
206 views

How do I combine multiple squares into one Tetris block?

I am learning Phaser by making a simple game—Tetris. I'm having difficulties: Can I use simple rectangles as tetrominoes or they should be sprites? I don't know how make the figure's block ...
4
votes
2answers
476 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 ...
0
votes
2answers
169 views

Integration error in high velocity

I've implemented a simple simulation of two planets (simple 2D disks really) in which the only force is gravity and there is also collision detection/response (collisions are completely elastic). I ...
1
vote
2answers
2k 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 ...
1
vote
1answer
444 views

How can I unify the collision handling of melee/spell attacks in a networked environment?

I am trying to figure a good way to create the battle system of a game. The game is fast paced and the gameplay needs to be precise (think hack n slash) What I would like to achieve is a simple and ...
0
votes
1answer
145 views

Having issues with pong physics, is my approach wrong?

I've been working on a pong clone, i've made games in the past but they have all been very hacky. This time I was trying to go for a better approach in terms of using OOP or patterns. So far the games ...
1
vote
1answer
202 views

How to correctly handle multiple movement key presses resulting in double the speed?

I am trying to implement acceleration and drag into my top-down 2D game. The player can move using the WASD keys. Acceleration works fine, but the way I handle the directional velocity causes the ...
2
votes
1answer
299 views

How do I make a sprite appear to sway with the wind?

I'm trying to find a method to simulate the effects of wind on various sprites in a side-view 2D scene. What relatively simple technique could I use for this? What I have in mind is to give these ...
0
votes
1answer
94 views

How long does the collision take?

I want to simulate a simple force-acceleration (rather than impulse-velocity) physical world made up entirely of disks and I'm having an irritating problem with my physics. When two disks collide, I ...
-3
votes
2answers
136 views

what is the ducking ability? [closed]

In my game framework I have this property: canDuck : Boolean = true Determines whether or not the hero's ducking ability is enabled. What does it mean ? regards
1
vote
1answer
202 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
votes
1answer
225 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 ...
2
votes
2answers
311 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 ...
0
votes
1answer
280 views

Determine speed of sprite

I'm trying to calculate the speed of my sprites in Cocos2d but I'm having some difficulties. I'm not sure which units of time/speed cocos2d uses. My background sprite moves 2 positions to left each ...
0
votes
1answer
72 views

Is there any reasons to make sprites and bodies line up?

So in LibGDX the Sprite objects position is where it's 0,0 mark is in the word. In Box2D a a bodies position is in it's center. So to line these up when you update the sprites position with the ...
0
votes
2answers
410 views

3D collision physics. Response when hitting wall, floor or roof

I am having problem with the most basic physic response when the player collide with static wall, floor or roof. I have a simple 3D maze, true means solid while false means air: bool ...
1
vote
2answers
59 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 ...
1
vote
0answers
123 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 ...
2
votes
2answers
128 views

Can I make a character solid but not lose non-physics behaviour?

My character can walk around in the world, but walks through other objects, for example a cylinder (stand-in for a cannon). To fix this I added a capsule collider to each of the character and ...
0
votes
1answer
184 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. ...
4
votes
2answers
214 views

2D Enemy AI reacting to sound

I'm currently working on a 2D top-down survival game and I'm trying to figure out a good method for enemies to detect player sounds. For instance - if the player fires his gun it should play a sound ...
1
vote
2answers
269 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?
0
votes
0answers
157 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 ...
2
votes
1answer
279 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' ...
-1
votes
1answer
56 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.
1
vote
1answer
548 views

2D Collision in JavaFX - Bad accuracy with .intersects()

I have several Shape objects - Circle, Rectangle and Polygon. I use the built-in .intersects(Bounds1, Bounds2) method to detect collision but it's quite inaccurate. Circle c1 = new Circle(20); ...
0
votes
1answer
104 views

How to make character gain acceleration?

I want to create more realistic physics for my 2D games. Currently, the character and the other game objects in my games start moving instantly (achieve maximum speed instantly) and stop instantly ...
1
vote
1answer
2k 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 ...
0
votes
2answers
260 views

How to design basic physics and movement behavior for 2D platformer?

I want to make a simple 2D platformer. I know some basic 2D physics and how to implement them in a game. How to make a character jump, accelerate, decelerate, etc. But I have no idea how to actually ...
1
vote
1answer
100 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 ...
1
vote
0answers
118 views

How do you calculate the rate of rotation using the accelerometer values in Android for a particular axis?

I am developing a simple game which involves a character moving up and down only along the Y axis. Currently I am using the accelerometer readings to change the Y velocity of the character. The game ...
1
vote
1answer
118 views

How to apply steering to a physics body correctly when using a physics engine?

I have a top down 2d game that uses a physics engine (Farseer). I'm using the standard steering behaviors to make the AI move around but I'm not sure the correct way to take the so called "steering ...
2
votes
1answer
584 views

Conceptual - What is the optimal way to combine steering behaviors with rigid body physics?

I am working on a simple 3D space simulator that makes use of the Bullet physics engine. The spaceships are rigid bodies that have a mass and hitbox so that they can be considered for collisions. At ...
0
votes
0answers
21 views

Handling gyroscope data

I'm working on a mobile game that allows user to rotate player around an axis using accelerometer. In addition to that, to allow fast, almost instant, rotation I thought of using gyro data. It seems ...
3
votes
1answer
241 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 ...
8
votes
3answers
3k views

Is a separate thread for game loop compulsory for simple games?

I am new to game development. In order to learn I am recreating this game on android platform. You can observe the game-play video at the above link. It is a simple game. I have read a lot of ...