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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2answers
53 views

How do you properly implement level boundaries in a physics room?

I have an issue with creating a proper boundary in GameMaker Studio when using a physics enabled room. My room has a gravity of 0, as it is in Space. My player object has the default values, but a ...
1
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1answer
23 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 youve ever ...
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3answers
39 views

Character animation in physics-simulated environment

What are the standard solutions for animating characters in physics-simulated environments? Let me explain what I mean - in most games characters are pretty much excluded from physics simulation - ...
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0answers
9 views

Spritekit physics engine inconsistencies [on hold]

reading this article I notice that spritekit has inconsistent results in its physics engine due to timestep issues. http://www.element84.com/comparing-sprite-kit-physics-to-direct-box2d.html It ...
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2answers
36 views

Character bounces/stutters down hills

I'm using Unity3D (not 4) and I'm experiencing a bit of a problem with character movement. I'm using a cylinder as a First Person player with a child Main Camera. In this cylinder is the stock ...
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1answer
27 views

Moving multiple hingejoints based on joystick input

I'm controlling a 2D side-viewed (facing right) stickman with a joystick. The movements are fairly intuitive: Joystick down -> Stickman crouches down Joystick up -> Stickman stretches out ...
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0answers
27 views

Resources to polish game physics [closed]

I am a total noob in physics and yet I am charged to work on games that include considerable knowledge and implementation of physics, any quick resources to follow, please? Thanks
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0answers
22 views

Friction effects on ball motion direction when crossing surfaces edges

I have a ball rolling from a high friction coefficient surface (snow) to a very low friction coefficient surface (ice). When the ball crosses the boundary at an angle, I believe it should change ...
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3answers
177 views

How do I resolve a sphere-triangle collision in a given direction?

I am trying my hand at game physics. I understand that the basic way to pull back a sphere when it collided is to negate the penetration distance: // If collided... // `distance`: distance form ...
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2answers
201 views

Timestep schemes for physics simulations

The operations used for stepping a physics simulation are most commonly: Integrate velocity and position Collision detection and resolution Contact resolution (in advanced cases) A while ago I ...
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1answer
75 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
92 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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0answers
16 views

PhysX - Revolute joint around unit vector

I'm using a right-handed coordinate system with (0,0,-1) = forward, (1,0,0) = right and (0,1,0) = up. PhysX version is 3.3.0. I have a unit vector which represents the axis around which my actor is ...
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1answer
258 views

How do I make my camera follow a Box2D object?

I'm implementing a camera in my game. It worked for regular objects, but I began using Box2D and obviously things changed a bit. I have a Body object that I want to draw at the center of the screen. ...
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1answer
145 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 ...
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0answers
13 views

Understanding the use of MTV for an elastic collision response

So, I'm trying to simulate polygon physics, both linear and angular. To calculate the MTV is easy in SAT (Minimum Translation Vector), and to use it to adjust position is also easy: PolygonA.center ...
3
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2answers
95 views

Why are my Box2D wheels slipping on ground?

I have a car, set up in Box2D as a rectangle connected with two wheels using WheelJoints: The wheels are defined as follows: FixtureDef wheelFixtureDef = new FixtureDef(); ...
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vote
1answer
508 views

Collider2D and Rigidbody2D, how do they work?

I have been learning JavaScript and Unity for a week now. I learned how to make Cube as a Ground and another Cube as a player and I used this code to make the Player Cube move forward and backward and ...
8
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3answers
579 views

Can I jump from A to B?

I'm making some rudimentary AI for my side-scroller and I need to know whether an AI unit can reach point B from point A simply by taking a jump. Flight trajectory of my characters is a bit unusal as ...
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0answers
12 views

CCTextField won't appear

I can't seem to add a CCTextField in my physics node, I tried all different methods, but it's still not happening. Here's my code: CCTextField *tf = [[CCTextField alloc] init]; tf.contentSize = ...
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1answer
113 views

Grid collision - finding the location of an entity in each box

I am trying to implement grid-based collision in a 2d game with moving circles. The canvas is 400x400 pixels. Below you can see the code for my Grid class. What I want it to do is check inside which ...
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2answers
121 views

How to add a constant horizontal force just like gravity?

I want to add a constant horizontal force, just like gravity to a projectile or a sphere moving in 3d space, which will make the projectile or ball or sphere or whatever be influenced by this force so ...
0
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3answers
102 views

What is the easiest way to make an object follow the edge of a sprite?

I have a rounded rectangle sprite and another sprite that's just a circle. I want the center of the circle to follow the edge of the rounded rectangle. Is there any easy way to accomplish this task? ...
3
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1answer
95 views

Unity's default integration method

Which method(s) does Unity provide for physical integration? RK4? Verlet? Euler?
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5answers
4k views

How do I detect the direction of 2D rectangular object collisions?

After this question, I need some more help. How can I find out which side of a rectangle a collision came from and react accordingly? The blue arrows are the paths that some circular objects ...
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1answer
112 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 ...
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1answer
4k views

LibGDX Box2D Body and Sprite AND DebugRenderer out of sync

I am having a couple issues with Box2D bodies. I have a GameObject holding a Sprite and Body. I use a ShapeRenderer to draw an outline of the Body's and Sprite's bounding boxes. I also added a ...
6
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1answer
112 views

How can I predict player-to-projectile collisions in Box2D?

I'm making a real time shooting game with Box2D as the physics engine. The gameplay is mostly about trajectory, like Angry Birds. I want to make a slow motion effect and move camera to the player when ...
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1answer
100 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); ...
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0answers
17 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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1answer
60 views

Bullet 3D Physics Objects Not Rotating?

So I've got Bullet 3D controlling the motion of objects rendered with DirectX. In the clipping below I've got 2 identical rectangles & 5 balls. The lowest rectangle has a mass of 0 and doesn't ...
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0answers
76 views

planning a spaceship path (possibly bezier curves) [closed]

Given a spaceship with a current position and velocity, I'm trying to plan a path to a given destination point, so that I can show a line plotting the course taken by the ship. It's in space so drag ...
1
vote
1answer
147 views

How do I calculate the motion of 2 massive bodies in space?

I'm writing code simulating the 2-dimensional motion of two massive bodies with gravitational fields. The bodies' masses are known and I have a gravitational force equation. I know from that force I ...
5
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1answer
128 views

Self colliding cloth physics

I've previously simulated cloth using Verlet integration but couldn't successfully get the cloth to collide with itself in an efficient way. The reason being is because I used a brute force algorithm ...
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2answers
43 views

How can I add an impulse to specific rigid bodies at rest?

Scenario Rocks falling down a rocky slope, with a flat surface at the bottom. When they land on the surface, the rocks move slightly before coming to a rest. GLESDebugDraw shows the bright orange ...
2
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1answer
42 views

Is there a way to view all colliders in a unity project at runtime (after the game have been deployed)?

I'm have created a small Unity project but physics has weird behavior (bug). Unfortunately it only happens on some specific hardware (after build), not on development machine. I don't know what is ...
14
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7answers
15k views

How do you calculate where a ball should go when it bounces off the bar?

I'm trying to wrap my head around this very Hello World-y problem in game development. I've created a TicTacToe game in XNA so I guess the next step would be a breakout clone. Keep in mind that I ...
0
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1answer
35 views

How to resolve OBB collision penetration?

I would think this is a common issue, but I couldn't find an answer that helped me. Help would be appreciated. In my game I have rectangular objects. They have rotating bounding box, aka not AABB but ...
0
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1answer
43 views

How can I avoid type checking in the physics side of collision handling?

I have a class responsible for handling the physics side of collisions. When the collision detector spots a collision, it notifies both entities in the collision to take care of gameplay. It also ...
4
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2answers
212 views

How can I synchronize ocean waves over the network?

I've been performing a little bit of research in my spare time on ways to increase the interactivity of environments in a networked game or simulation. One of my areas of research is fluid-dynamics ...
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1answer
31 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 ...
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6answers
318 views

Increasing efficiency of N-Body gravity simulation

I'm making a space exploration type game, it will have many planets and other objects that will all have realistic gravity. I currently have a system in place that works, but if the number of planets ...
2
votes
2answers
107 views

How to correctly implement player acceleration caused by player input

In my game I implement movement in the Player class like so: // called from Player's update() method, which is called from the gameloop. void move(){ velocity.x += acceleration.x; velocity.y ...
1
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1answer
67 views

2D how to add graphics for liquid physics?

I was always wondering how to add the graphics to a a blob body for example, regardless of what engine or library you are using, i want to know (theoratically) how to move from this state : ...
4
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2answers
151 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 ...
0
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1answer
33 views

Accelerated Motion

I'm making a menu for my game with SDL, when you click on an option a sub menu slides down and is shown, just sliding down is really boring, so I want it to accelerate(like if gravity was pulling it) ...
3
votes
1answer
210 views

How do I run a callback when all objects have stopped moving?

I'm using Bullet and want to take some action once all objects in a dynamic world have reached 0 velocity (or at least a value that's very close). I was trying to iterate over all of them all the ...
9
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2answers
1k 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 ...
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2answers
3k views

Why is RK4 better than Euler integration?

At the end of these great slides, the author compares all the different integrators presented. One way or another, they all fall short except for Improved Euler Integration and Runge Kutta 4 ...
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1answer
89 views

Unity: Rolling a ball around a spherical planet with forces

I'm trying to make a game in Unity where the player character is a ball (a sphere), and the game world is a planet (a very large sphere) that the ball can roll around on. The ball can be rolled in any ...