Relating to the motion of objects through space and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.
6
votes
2answers
310 views
Is it possible to have concurrent collision detection where every entity acts at exactly the same time?
There are many algorithms that can be used for collision detection. In many cases we check for an overlap in coordinates of an entity.
If we make a triangle a,b and c. We have 2 entities at a and b ...
6
votes
2answers
231 views
Elliptical orbit modeling
I'm playing with orbits in a simple 2-d game where a ship flies around in space and is attracted to massive things. The ship's velocity is stored in a vector and acceleration is applied to it every ...
6
votes
4answers
692 views
Server-side physic simulations with hundreds of players
I’m currently working on a singleplayer physics-orientated game where I would like the physics to be simulated server-side. This because the game will have leadersboards, persistant player ...
6
votes
1answer
223 views
How do I change the speed of an object without changing path travelled?
I have a ball which is being thrown from one side of a 2D space to the other. The formula I am using for calculating the ball's position at any one point in time is:
x = x0 + vx0*t
y = y0 + vy0*t - ...
6
votes
1answer
158 views
How can I derive force vectors from velocity vectors?
I'm making a 2d shooter ala Geometry Wars. I've got my own simple physics at work driving the background grid and all my entities. To move anything in the world I apply a Vector2d force to it. The ...
6
votes
2answers
2k views
What is your Unity 3D physics engine budget for iOS games?
I'm testing Unity for a game that I'm building, and I've touched its limit.
My test scenario: a wanna-be house with 200 elements (cubes rescaled) no textures, box colliders and rigid bodies for each ...
6
votes
1answer
164 views
Determining whether two fast moving objects should be submitted for a collision check
I have a basic 2D physics engine running. It's pretty much a particle engine, just uses basic shapes like AABBs and circles, so no rotation is possible. I have CCD implemented that can give accurate ...
6
votes
2answers
658 views
How to implement friction in a physics engine based on “Advanced Character Physics”
I have implemented a physics engine based on the concepts in the classic text Advanced Character Physics by Thomas Jakobsen. Friction is only discussed very briefly in the article and Jakobsen himself ...
6
votes
1answer
384 views
What are some good methods of implementing RTS-style Box selection?
i'm just scouting around for different methods of implementing a typical rts box selection (not the 2D box on the screen, but what units are selected with the box) when selecting units, and would ...
6
votes
3answers
1k views
Is there a good existing starting point for realistic 2d racing car physics?
I'm trying to get a realistic behaving racing car into my 2d top-down game.
Making a very simple car that drives around is straight forward but I want a reasonably sophisticated model that models ...
6
votes
1answer
547 views
Bringing a Box2D, Physics Enabled game Online?
Lets say, to simplify the problem of online games a bit, my goal would be to run a near identical simulation on multiple computers in sync. Would sending commands be a good idea?
Now if only sending ...
6
votes
1answer
236 views
How do engines avoid “Phase Lock” (multiple objects in same location) in a Physics Engine?
Let me explain Phase Lock first: When two objects of non zero mass occupy the same space but have zero energy (no velocity).
Do they bump forever with zero velocity resolution vectors or do they ...
6
votes
1answer
208 views
Changing orientation by applying torques
Suppose you've got an object floating freely in space. You have a vector you want this object to point towards, and a vector representing the direction it's currently facing. From these two, you can ...
6
votes
1answer
145 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 ...
6
votes
2answers
356 views
multiplayer networking with physics
I'm curious how multiplayer networking with physics is implemented in racing games.
We have a physical world with multiple fast-moving vehicles controlled by different people.
Let's say that vehicles ...
5
votes
5answers
824 views
Are game programmers aware of all the physics derivatives?
I am trying to study XNA for game programming. XNA has many methods that can simplify developer's life, such as reflecting the vector when it hits a solid plane.
I know these are good and developers ...
5
votes
3answers
520 views
3D game on a planet
Would it be much more work to create a 3D game on a planet rather than on a flat plane? What engines would support this and what techniques would I use?
An example would be a small sphere the player ...
5
votes
2answers
2k views
Is it worth it to use Bullet for 2D physics instead of Box2D for the sake of learning Bullet?
There isn't much more to the question. I'm not concerned about overhead, as I'm sure they are both fine for my purposes. Basically, I am familiar with Box2D concepts because of the Farseer Physics ...
5
votes
3answers
259 views
How can I change the acceleration of an object to arrive at a particular time?
I'm trying to write some code to change an acceleration factor so a ball will arrive at a destination in a desired time.
The problem is I don't know time (t) but I do know I want it to arrive at (t - ...
5
votes
4answers
378 views
Making a Box2D ball bounce to constant height
I want to create a game like Doodle Jump. I'm using libgdx and Box2d. I needadvice on how to make my ball bounce constantly and with the same height.
I've tried setting the ball's body restitution ...
5
votes
5answers
433 views
How do I implement deceleration for the player character?
Using delta time with addition and subtraction is easy.
player.speed += 100 * dt
However, multiplication and division complicate things a bit. For example, let's say I want the player to double his ...
5
votes
4answers
344 views
How would one generate a texture for cracks in different materials?
I would want to have the ability to simulate different variables like brittleness, or other variables to get varied end results.
I would mainly need to generate impact cracks, so it would need to ...
5
votes
3answers
309 views
'Spring' physics
I'm trying to put together a struct or a method of some sort that will allow me to check the relative position between two objects, and if they're too far apart, apply a force that will draw them ...
5
votes
3answers
1k views
Car (or other “object”) acceleration and braking: how to?
I'm not good in math so I'm here to ask you how to manage, in a simple 2d game, the car acceleration and braking.
I'm trying to develop it (as a hobby) in c# and sdl.net.
5
votes
2answers
305 views
How to make a fan like behavior
I am making a game in Unity. I have an object e.g. cube. I want to release air from it like fan so that when other cubes come closer, it throws them away. What velocity,force etc I will need to do ...
5
votes
4answers
326 views
Sharing data between graphics and physics engine in the game?
I'm writing the game engine that consists of few modules. Two of them are the graphics engine and the physics engine.
I wonder if it's a good solution to share data between them?
Two ways (sharing ...
5
votes
1answer
1k views
How does 2D Game Physics work? [duplicate]
Possible Duplicate:
How do I build a 2D physics engine?
If we take the game Angry Birds that had big success lately I were thinking how do they implement the physics in a game like that?
...
5
votes
1answer
132 views
Physics/Logic behind self-bounce
I have a game that I am currently working on and I have a problem.
What would a ball look like when it makes itself bounce. Say, for example that the ball had its own "inner power", was made out of ...
5
votes
1answer
315 views
Calculate gears rotation for a realtime simulation
Hi I'm trying to do a game with real time simulations of gears. There is a big Gear with inside a smaller gear.
I managed to draw gears with different diameters but equal size teeth, but if i try to ...
5
votes
5answers
789 views
Glass shatter simulation
I need to make a simulation with stone thrown on the glass window. Could you please help me choose the tools to make it quickest and easiest? And maybe some tips how to do it :).
I mean, I was ...
5
votes
2answers
402 views
Physics in my game confused after restructuring the Game loop
I'm on my way with making a game in Java. Now I have some trouble with an interpolation based game loop in my calculations.
Before I used that system the calculation of a falling object was like ...
5
votes
3answers
310 views
How is 'mass' handled in video games?
Mass is one of the basic scalar quantities, which is required in most rigid body physics calculations.
Does every, EVERY, object which moves in a game get mass defined in the code, or is it allotted ...
5
votes
1answer
1k views
Box2D Difference Between WorldCenter and Position
So this problem has been brothering for a couple of days now. First off, what is the difference between say Body.getWorldCenter() and Body.getPosition(). I heard that WorldCenter might have to do ...
5
votes
2answers
2k views
2D soft-body physics engines?
Hi so i've recently learned the SFML graphics library and would like to use or make a non-rigid body 2D physics system to use with it. I have three questions:
The definition of rigid body in Box2d is
...
5
votes
2answers
2k views
How to make bird to fly using box2d
I am new to Box2D, I have set gravity to 10. How to make an object fly in space even though the gravity is 10. What are the properties I need to set to make object fly? Is there any different ...
5
votes
1answer
548 views
Soft body, where to start learning?
I want to ask you about some resources to learn simulating soft bodies, do you know some good knowledge sources?
I asking because I want to make car crash simulator, I've made something but it didn't ...
5
votes
1answer
300 views
Predicting physics/trajectory for pool/billiards games
I'm thinking of making a quick proof of concept of a billiard-style game mechanic, where the player has perfect information of what is about to happen.
Here's a good example:
I'm only mildly ...
5
votes
3answers
5k views
2D character controller in unity (trying to get old-school platformers back)
This days I'm trying to create a 2D character controller with unity (using phisics). I'm fairly new to physic engines and it is really hard to get the control feel I'm looking for. I would be really ...
5
votes
2answers
432 views
Collision Detection/Response in Vector-based levels
I have a 2D side scroller whose levels are stored as vectors (that is, a bunch of lines) which looks like this:
How would I detect that I'm colliding with one of these lines, and react accordingly ...
5
votes
3answers
1k views
Resources to learn programming rigid body simulation
Where I can start learning about simulating rigid bodys 2d and 3d ?
5
votes
2answers
629 views
3D Particle-Geometry collision
I am programming a particle engine for a 3D game written in XNA. I was wondering if somebody could point me in the right direction or perhaps give me some pointers in making the particles collide with ...
5
votes
1answer
756 views
Correct way to use Farseer Physics in XNA
I am using Farseer Physics for my 2D sidescroller game and I'm not sure how to proceed with it. I currently have a Sprite class (handles nothing but graphics), a GameObject class (contains specific ...
5
votes
3answers
216 views
Need physics algorithm for modeling ceiling collapse in voxel-based game
I'm looking for algorithms on how to model the physics of cave-ins/collapses for a game idea I am working on. The game allows the player to extensively mine 3D voxel-based asteroids, and I want areas ...
5
votes
2answers
321 views
“Super meatboy”-ish replay
I'm making a platformer built from mini-levels - and I want to create a sort of a replay of all the player tries that the player did for the level.
My question is - what is the best way to record the ...
5
votes
2answers
2k views
Physics or Time-Based Animation In Corona SDK (iOS) Using Box2D
I am part way through creating a Doodle Jump clone for iOS using Corona SDK. I'm currently using the physics engine (box 2D). It's not a straight clone, but I need the basic principles in place to ...
5
votes
3answers
1k views
2D Platformer Collision/Physics Problems
I'm making a 2D platformer similar to Terraria, although I'm having some problems with some collision detection code. I'm using the code from the AppHub Platformer sample, but tweaked so it fits with ...
5
votes
2answers
1k views
Web workers for HTML5 game physics simulation?
A bit related to this question.
The idea is to guarantee the same physics behavior as much as possible. Would it be possible to run fixed time step physics on a web worker? The UI would update ...
5
votes
1answer
209 views
Splitting an object into two
I'm using Farseer physics engine.
I have a simple rectangle body and would like it to split into two pieces given a starting coordinate (where the bullet enters the object) and ending coordinate ...
5
votes
1answer
428 views
Strangeness when simulating a chain
I'm using box2d and I simply hook up 10 points each with a similar length constraint to the adjacent point.
When I move 1 point, the others follow just like a rope/chain. Just like one would expect.
...
5
votes
2answers
1k views
How can I implement rectangle collision response?
I am working on a game in JavaScript and my current implementation of collision uses the shortest distance to push the intersecting object away, which isn't always correct. I've made this diagram of ...
