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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22
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7answers
1k views

Multithreading 2D gravity calculations

I'm building a space exploration game and I've currently started working on gravity ( In C# with XNA). The gravity still needs tweaking, but before I can do that, I need to address some performance ...
0
votes
1answer
176 views

Resolving a collision between point and moving line

I am designing a 2d physics engine that uses Verlet integration for moving points (velocities mentioned below can be derived), constraints to represent moving line segments, and continuous collision ...
1
vote
1answer
92 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 ...
0
votes
2answers
106 views

How can I simulate a rigid body bounced from a wall in 3D world?

How can I simulate a rigid sword bounced from a wall and hit the ground (like in physical world)? I want to use this for a simple animation. I can detect the figure and the size of the sword (maybe ...
4
votes
1answer
143 views

Correct order of tasks in each frame for a Physics simulation

I'm playing a bit around with 2D physics. I created now some physic blocks which should collide with each other. This works fine "mostly" but sometimes one of the blocks does not react to a collision ...
-4
votes
3answers
771 views

Homemaking a 2d soft body physics engine

hey so I've decided to Code my own 2D soft-body physics engine in C++ since apparently none exist and I'm starting only with a general idea/understanding on how physics work and could be simulated: ...
1
vote
1answer
665 views

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, ...
1
vote
3answers
349 views

Bouncing ball isssue

I am currently working on the 2D Bouncing ball physics that bounces the ball up and down. The physics behaviour works fine but at the end the velocity keep +3 then 0 non-stop even the ball has stopped ...
4
votes
1answer
376 views

Do I need path finding to make AI avoid obstacles?

How do you know when a path-finding algorithm is really needed? There are contexts, where you just want to improve AI navigation to avoid an object, like a space -ship that won't crash on a planet ...
1
vote
1answer
1k views

Jumping with Mecanim synchronization

I am using Unity3D 4.1 for one of my projects. I have a robot character which is always running. I am using mecanim animation system. What I really want:When I press Space bar, the character should ...
2
votes
5answers
1k views

How to Make Objects Fall Faster in a Physics Simulation

I used the collision physics (i.e. Box2d, Physics Body Editor) and implemented onto the java code. I'm trying to make the fall speed higher according to the examples: It falls slower if light object ...
1
vote
1answer
99 views

Adding Leniency to Jumping Mechanic

I have written some jumping code for my player in a platformer game. At the moment it has some basic logic which says that the player can jump if he is on the ground. The pseudocode looks something ...
2
votes
1answer
490 views

physics of 2D car racing game with heightmap

I want to develop a simple car racing game where the road is defined by a heightmap. It looks basically like this: The player can use throttle and brake to control the car. I'm wondering what the ...
4
votes
4answers
434 views

The physics equation for a perpetual seesaw

I am trying to create a game that involves two or more people jumping on a seesaw and propelling each other in the air. I need help with the physics equations Assume no friction and no air ...
8
votes
3answers
1k views

Calculation of Inertia Tensors

Bit of a complex and lengthy question that, I'll admit, I don't quite understand very well yet so I will try and explain as best as I can. Short Version: Is there a general c++/physx formula out ...
0
votes
1answer
213 views

Performing intersection testing in world's or object's space?

Am adding basic ray casting and collision detection for my game, also adding bounding volumes/collision mesh. Given that the ray is cast in world space and each mesh's node can track world ...
0
votes
1answer
391 views

Box2d making a body follow the mouse accurately

I am trying to make a box2d b2Body follow my mouse position. This is the code I am using at the moment but it is not performing very well: deltaPos = mousePos - body->GetPosition(); deltaPos *= k; ...
0
votes
1answer
473 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 ...
3
votes
1answer
113 views

What is a collision shape?

I am a business developer who is new to game programming. In learning Stencyl, I see that there are things called collision shapes associated with tiles. This seems to be a standard term in game ...
0
votes
1answer
272 views

Trouble with a modified parallax scrolling concept

I have a set of layers (each of them being a list of items) moving with different speeds as I mentioned here: http://stackoverflow.com/a/18962019/270197. Layers back in the scene move with slower ...
1
vote
1answer
100 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?
-1
votes
1answer
292 views

Air Resistance of a Falling Object

I am applying air resistance to a falling sphere using the Euler method. If someone could have a look and tell me if my implementation is correct or offer any tips, it would be highly appreciated. ...
0
votes
1answer
447 views

Detect when a bullet rigidbody is on ground

I have a rigidbody that is on top of a plane or another rigidbody. How do I check if said rigidbody is on top of it? I tried to check the Y-part of the velocity but it is never 0, it is always a ...
7
votes
2answers
340 views

How to implement a tractor beam?

I'm working on a game where the player can pick up objects using something like a tractor beam, and carry them around. Attracting the object towards the center of the beam is not difficult. But once ...
4
votes
1answer
706 views

GGX specular BRDF is way over 1!

Now, the classic Torrance derivation for roughened surfaces which Cook took into vectorized form yields the familiar parametrization of a specular BRDF where we have the NDF which decides how much ...
0
votes
1answer
293 views

Showing trajectory indicator

From the image you can see that the ball fired on the left that fire behind it, does not match the calculated trajectory. Im drawing the ball trajectory using an equation from a SO question, this is ...
0
votes
0answers
759 views

Platform game: applying gravity and jumping [duplicate]

I am making a 2D platform game in Java but I don't know how to apply gravity and jumping on my player and other living creatures in game that it looks natural and that it is physical correct. I have ...
4
votes
2answers
380 views

Modular spaceship control

I am developing a physics based game with spaceships. A spaceship is constructed from circles connected by joints. Some of the circles have engines attached. Engines can rotate around the center ...
0
votes
1answer
248 views

How to simulate the movement of a ball in 2D due to force, gravity, and friction with surface?

I have a ball which I kick with some force. It has a starting x,y position, sat (2,3) and an intended target x,y say (7,8) position. That means I have to translate by (7-2, 8-3) i.e. 5 x units and ...
0
votes
0answers
81 views

Separating axes test for moving objects

I am having trouble figuring when a given case that is often mentioned actually comes into being. In multiple GDC presentations, and in Eberly's Game Physics book SAT on moving objects it is also ...
2
votes
0answers
163 views

Collision detection with an irregular curve

I'm building a custom physics engine to accompany a level-editor. This image shows how the level-editor outputs levels: Now, some explanation is in order. The curve is defined by the red points. ...
0
votes
1answer
185 views

Issues calculating frame independent movement

I'm developing a Breakout style game in C++ using SDL. The problem so far is that the ball slows down and speeds up for no particular reason. The slowdowns usually last a few seconds. EDIT : When ...
1
vote
1answer
395 views

How can I implement a simple “jump” action with three.js and/or Physijs?

Assume I have a simple Physijs object like this car. How can I adapt something like this to "jump" (hydraulics ftw!) when pressing spacebar for instance? I'm currently thinking applyCentralImpulse ...
-1
votes
2answers
357 views

Move a player in the opposite direction they are looking

I'm looking to move the player in the opposite direction they are facing with a specified force. Rather than try to explain that better I created an image showing what I mean, I've tried reversing ...
9
votes
1answer
330 views

Multiplayer platformer - Are server corrections normally required with a single client on the server?

I am currently working on a rather simple multiplayer platformer. I read quite a bit of articles on the techniques used to hide latency, but I still fail to get my head around certain of the concepts. ...
3
votes
2answers
631 views

Unity 4 - Some Rigidbodies Won't Fall Asleep

I'm having this problem in the free edition of Unity 4.1 where rigidbodies aren't falling asleep (and yes, I've tried playing with the sleepVelocity and sleepAngularVelocity values!). I've read the ...
3
votes
1answer
269 views

Simple 3D collision detection for general polyhedra

I have correctly set up a SAT system. I now need to determine a simple, fast, and general purpose collision detection mechanism to identify the collision points. These points will then be used to ...
7
votes
1answer
1k views

A simple flight simulator

In a 3D flight simulator with a Crimson Skies level of realism (as in, arcade level rather than realistic), how do you determine the movement of an aircraft each game clock tick? (Crimson Skies is an ...
3
votes
1answer
240 views

GPGPU physics & game logic

I'm wondering about gpu accelarated physics after reading about Erwin Coumans presentation on GPU accelerated physics: http://www.gdcvault.com/play/1018185/GPU-Rigid-Body-Rigid-Body (demo video here: ...
1
vote
3answers
485 views

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 ...
4
votes
3answers
152 views

Particle dynamics simulation and conservation of energy

Suppose you want to simulate the dynamics of a particle subject to Newton's laws of motion. We could just fix a discretization of the time dt and solve approximate differential equations like ...
0
votes
1answer
691 views

gamemaker getting a ball to bounce 90 degrees off of a 45 angle

I am trying to get a circle to bounce off a 45 degree diamond shap using Gamemaker Studio. I would like the ball to bounce in straight lines so my directions would be 0, 90, 180, or 270 degrees, ...
22
votes
5answers
6k views

Lag compensation with networked 2D games

I want to make a 2D game that is basically a physics driven sandbox / activity game. There is something I really do not understand though. From research, it seems like updates from the server should ...
2
votes
1answer
196 views

Implementing a time scale in game with fixed physics update

I'm currently putting together my game loop based on the "Fix Your Timestep" article at gafferongames.com. This is going fine, but I'm also trying to implement a 'time scale', i.e. a way to control ...
3
votes
2answers
269 views

When to detect and respond to collisions?

I've usually implemented collision detection like this in the past: Move entity Check if it collides with anything Resolve the collision by moving it back That's also the approach employed by most ...
1
vote
1answer
199 views

Calculating distance by force

I am trying to predict a ball(sphere) movement. The formula of force which I know is Force=Mass*Accelaration What I want is how can I get distance or displacement by giving particular force? I want ...
4
votes
3answers
255 views

Programming atmosphere for game

I've recently started making game and I want to implement there an atmosphere. My plan is to include in game many compartment, tubes and ventilations. For example if I open and airlock from room with ...
1
vote
1answer
247 views

Pick and Drop the Ball Testing Without Replicating the Physics Frame

I am making a program that pick, drag, and drop the ball. In real life, once you pick the ball and drop it, whenever the available object is (what you see is what you get) will only be picked and ...
2
votes
1answer
316 views

Box2D: Asteroids-Like Spaceship Physics

I'm new to Box2D (JavaScript) (and the world of physics/mathematics) so I'm having a hard time working out the methods I need to use to make a spaceship act like it does in the classic arcade game ...
1
vote
1answer
257 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 ...