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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1answer
220 views

How can I test if an object will “fit” during pathfinding?

I'm tinkering around with a 2d game where obstacles are polygons of arbitrary shapes, sizes and locations, and movable entities (players/enemies) can also be of arbitrary sizes. What's a good general ...
4
votes
1answer
255 views

Why do my velocity estimates have such a large margin of error

I am writing a script in unity that applies a force to the object to advance it a set distance in an environment without friction or drag, producing a cosine force curve. However, as the target ...
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3answers
751 views

Calculating buoyancy force

I am trying to simulate a buoyancy force for objects submerged/suspended in a fluid in a 2D environment. According to Game Physics: Engine Development: How to Build a Robust Commercial-Grade Physics ...
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1answer
2k views

Non axis aligned bounding box collision and physics

Exactly how much more expensive, and while we're at it, difficult, is it to have non-axis aligned bounding boxes in your framework? I realise that it very much depends on what you're trying to do, so ...
4
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1answer
702 views

Heightmap Physics Optimization/Improvement

I'm working on implementing the physics surrounding a player walking on a heightmap. A heightmap is a grid of points which are evenly spaced on the x and z axes, with varying heights. The physical ...
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1answer
2k views

Farseer and 2D Action sidescroller game

I'm thinking about using Farseer inside my game (I'm not good in physics), which isn't a bad idea. However something happened while I was thinking about that, I found this tutorial: ...
4
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1answer
413 views

Taking Physics into account for AI Planning

What I've seen in most Game Engines and game engine design is that the Physics Engine is the be all end all system. Basically, AI for example may want to travel to some position, but it simply ...
4
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1answer
349 views

How to take into consideration the effect of initial rotation of a ball hitting & reflecting off a surface

Hey all, I am trying to take into consideration the effect of inertia of the initial rotation of a ball, hitting a surface, into the exit velocity vector of the ball. My current theory is this: ...
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1answer
131 views

How to manage sleep/awake state of physics body

I have a loop, which updates all the physics, inside the loop I'm updating the position of the objects, first thing is the gravity, which pulls all the objects to the bottom. Now my question is, how ...
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1answer
263 views

Networked Physics - Interpolation Causes Physics Engine to Explode

A major issue I am encountering right now is that my physics engine (BEPU) and my network interpolation are conflicting with each other. The player is a physics object, and so the physics engine ...
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1answer
2k views

making a box2d body move along a Bezier curve/ arc path

I have been trying to make a box2d body move along a Bezier curve/ arc path. Most of the posts I've seen recommend an approach of manipulating SetLinearVelocity and SetTransform to arrive at an ...
4
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1answer
333 views

BEPUphysics collision with generated terrain?

I've got randomly generated terrain which is stored in a indices and vertex buffer. How do I go about using this for collision in BEPU? It seems I can do it with a Mesh but it would be a waste to ...
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1answer
583 views

Multiplayer box2d networking for turn based game

I am currently in the planning stages for a 2D game for mobile devices which I will be making in C++ using cocos2d-x. The game will be turn based and each turn will have a phase in which the physics ...
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2answers
321 views

Box-box contact information

I have two colliding boxes, How i can calculate contact information like (contact normal, contact point and penetration) . Is there any simple algorithm . Note: i'm using XNA .
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1answer
723 views

RK4 Bouncing a Ball

I am trying to wrap my head around RK4. I decided to do the most basic 'ball with gravity that bounces' simulation. I have implemented the following integrator given Glenn Fiedler's tutorial: /// ...
4
votes
1answer
589 views

Tried and true basic movement physics (jumping, not walking through stuff)?

If I sat down long enough, I'm sure I could make this happen, but I don't want to reinvent the wheel if I don't have to, especially if XNA has patterns in place for doing this. For now, I'm working ...
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1answer
231 views

Box2D stable range and position

Box2D marks stable range of object size is 0.1M ~ 10M. This specifies object size range. How about space size? If I make an 1M object at (1000.0f,1000.0f) position? Is it can be stable? Or should I ...
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2answers
412 views

How to detect and collide two elastic line segments?

There are 4 moving physical nodes in 3D space. They are paired with two elastic line segments / strings (1 <-> 2; 3 <-> 4). Part I: How to detect the collision of two segments? Part II: On the ...
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1answer
790 views

Problem with box2d at beggining

I have problem with simple box2d physics: I have two bodies : 1 - static box , 2 - dynamic box. I only want to this dynamic box fall on this static, and lay. But now it looks like that at end , ...
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2answers
357 views

what is the name of the group of properties: position, velocity, acceleration, rotation

They say naming things is one of the hardest problems in computer programming, they were right. Given the pseudocode below, what is a more appropriate name for this collection of properties? Course, ...
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4answers
595 views

Math and physics, where to start? [closed]

the only math I know how is to add the velocity to position. Thats it. i would like to know how to do more stuff, physics, collision detection with stuff other than perfect circles, etc. But where ...
3
votes
2answers
351 views

How to account for speed of the vehicle when shooting shells from it?

I'm developing a simple 3D ship game using libgdx and bullet. When a user taps the mouse I create a new shell object and send it in the direction of the mouse click. However, if the user has tapped ...
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2answers
2k views

Easiest Way To Implement “Slow Motion” and variable game speed in XNA?

I have an XNA 4.0 game that I want to be able to switch into slow motion and back again to full speed every now and then. So if you kill an enemy the game switches into slow motion as they explode ...
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1answer
572 views

How to bounce a 2d point particle off of a circular edge

In a prototype I'm building, a particle can spawn anywhere within a larger, confining circle. Important to note is that the particle will not spawn in the origin of the larger circle, but anywhere ...
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2answers
3k views

How to implement “Flick” gesture for throwing an object in the 2D realm

I am trying to implement a FLICK gesture for throwing a ball from point A to point B on the iPhone. This is my current plan.... Using touchesBegan and touchesEnd I can find the direction I need to ...
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2answers
166 views

Creating shattering effects without having to use actual physics?

For certain effects like glass shattering and falling objects cracking to reveal their inner contents, are there any tricks or ways to implement these fracture physics without having to use actual ...
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1answer
1k views

Platformer Starter Kit - Collision Issues

I'm having trouble with my game that is based off the XNA Platformer starter kit. My game uses smaller tiles (16x16) then the original (32x40) which I'm thinking may be having an effect on collision ...
3
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1answer
495 views

Maximum range of projectile fired at given force and elevation

I've gone over this again and again, and my result is obviously wrong when viewed in-action. Here's the initial formula I converted (first one): http://en.wikipedia.org/wiki/Range_of_a_projectile ...
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3answers
1k views

Optimizing Bullet and ODE Physics on consoles and mobile phones

I'd like to use either Bullet or ODE on low powered devices (mobile and consoles), but the frame rates are below the acceptable 25-30fps for simulations. I've found that one articulated body by ...
3
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1answer
114 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 ...
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1answer
351 views

Fluid Particle Grid

So recently I have been looking at some fluid simulation techniques, specifically Smoothed Particle Hydrodynamics. One of the key components is a grid to avoid O(n^2) searches. I have been having some ...
3
votes
3answers
323 views

Adding 'swerve' to a direction

I'm not much of a maths expert, so this is probably quite straight forward. I was playing a soccer flash game where you take free kicks. You provide Power, Swerve and Direction. I'm reading up on ...
3
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1answer
114 views

Unity's default integration method

Which method(s) does Unity provide for physical integration? RK4? Verlet? Euler?
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3answers
307 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 ...
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votes
1answer
111 views

How do you prevent AABBs from passing through each other?

I know what an AABB is, but I don't know how you would check for collision with an object that is going really fast. If an object goes fast enough, it can skip over other bounding boxes without it ...
3
votes
1answer
4k views

Creating sideways friction in a 2D top down racer

I've been playing around with trying to create some kind of top down racer but I'm having trouble getting the car to turn properly. At the moment this is the code I have to update the position of the ...
3
votes
1answer
753 views

Angular Velocity

Hey, I have a particle that is hit with a force F at a particular position on the ball P. How can I calculate the angular velocity of the X,Y and Z axis? The actual rotating of the object should be ...
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5answers
337 views

Forcing one projectile to follow close behind an initial projectile

I'm shooting out a projectile and I want another projectile to closely follow it. I can't simply shoot out the second projectile at a slightly lesser time because the first projectile may change ...
3
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2answers
92 views

Radiometric quantities and time in rendering

Often in papers people use various radiometric quantities, mostly radiant flux, radiant intensity, radiance and irradiance. It seems to me that all of these quantities are dependent on time. For ...
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1answer
258 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: ...
3
votes
1answer
930 views

Engine for 2D Top-Down Physics-Based Skeletal Animation

I just watched at the Sui Generis video, and was completely amazed. Specifically, the part where the big troll thing is beating up the player with his flail. This got me really excited, and I would ...
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4answers
3k views

2D Collision in Canvas - Balls Overlapping When Velocity is High

I am doing a simple experiment in canvas using Javascript in which some balls will be thrown on the screen with some initial velocity and then they will bounce on colliding with each other or with the ...
3
votes
1answer
296 views

Why does my ball always bounce perpendicular to walls?

I'm using Box2D. I think it's something to do with wall's fixture definition, but when a ball goes toward a wall at a 45 degree angle, I would expect it to bounce off at 135 degrees, but it always ...
3
votes
2answers
1k views

Jumping Vs. Gravity

Hi i'm working on my first XNA 2D game and I have a little problem. If I jump, my sprite jumps but does not fall down. And I also have another problem, the user can hold spacebar to jump as high as he ...
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votes
3answers
378 views

Collision filtering techniques

I was wondering what efficient techniques are out there for mapping collision filtering between various bodies, sub-bodies, and so forth. I'm working on a physics engine and I need ways for a user to ...
3
votes
1answer
291 views

Approximating walking physics via simpler sliding physics

I am modeling walking insects. I implement them as cuboids and use forces (including friction and drag), to control motion. However, the movement characteristics of this 'sliding box' physics don't ...
3
votes
1answer
286 views

Car physics - velocity and latheral force

Im developing simple car racing game. To turn a car, I need to calculate slip angles for each tire and then use those angles to find lateral force (using Hans B. Pacejka magic formula). One thing I ...
3
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1answer
282 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 ...
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3answers
201 views

Scaling Sound Effects and Physics with Framerate

(I'm using XNA and C#) Currently, my game (a shooter) runs flawlessly with 60 FPS (which I developed around). However, if the framerate is changed, there are two major problems: Gunshot sound ...
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1answer
529 views

Making particle bounce off a line with friction

So I'm making a game and I need a particle to bounce off a line. I've got this so far: public static Vector2f Reflect(this Vector2f vec, Vector2f axis) //vec is velocity { Vector2f result ...