Software for simulating physics like collisions, forces, mass, joints, motion etc. Examples of physics engines are PhysX, Havok, Bullet and ODE.
15
votes
6answers
7k views
How do I build a 2D physics engine? [closed]
The most advanced games I've made are a 8-ball pool game made with the physics engine Box2dFlashAS3 and a platform game with levels.
When I did platform games, I've always wished to know how to make ...
14
votes
7answers
10k views
What are some known 2D/3D physics engines for XNA?
I'm looking for a physics engine to use in an XNA project (2D or 3D). Because it's for XNA, it needs to fulfill some requirements:
Not necessarily free, but close to it is obviously preferred
...
13
votes
6answers
3k views
Do any open source JavaScript 3D physics engines exist? [closed]
I'm working on a web-based 3D FPS game using WebGL, HTML5 and JavaScript. It is supposed to target PCs and net-books with WebGL-enabled browsers installed.
I'm wondering if there's an existing open ...
13
votes
4answers
465 views
How should I handle tiny objects in a physics engine?
I am making a 3D physics engine for throwing dice. Up until now a dice has been 1x1x1m and gravity has been 9.82 m/s^2. This of course does not look realistic as the dice will respond to everything in ...
13
votes
1answer
1k views
Any fixed-point portable open-source 3D physics engines?
I'm looking for a fixed-point 3D physics engine (basic kynematics and collision detection-resolution... nothing too fancy.)
I need fixed-point math because I'd like to have deterministic results, for ...
12
votes
3answers
603 views
Resolving a collision with forces
In my 2D physics engine, I can detect AABB vs AABB collisions, and resolve them by finding the shortest penetration vector and adding it to the AABB's position.
Doing this "pushes" the first AABB ...
11
votes
3answers
1k views
Advice needed for a physics engine
I've recently started a project, building a physics engine.
I was hoping you could give me some advice related to some documentation and/or best technologies for this.
First of all, I've seen that ...
10
votes
4answers
2k views
How to build a bones animation engine?
I want to develop a flash game. It would draw a stick man, and edit his pose.
I think what I need to learn are bones animation and physics engine.
Can anyone introduce some good resources to learn ...
10
votes
2answers
3k views
Making a character move along a curved slope in a World with gravity
I have seen this game
Fancy Pants 2 . And the thing I noticed apart from the physics and beautiful animations is that the character is moving along slopes , even curved slopes. I have little ...
7
votes
2answers
542 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 ...
7
votes
1answer
458 views
Finding the point of collision
I'm writing a 2D rigid body simulator. The objects being simulated are convex polygons. My question involves how to decide on the "point" of collision, so that when I apply a response force, I can ...
7
votes
1answer
185 views
How do I fix objects “popping” or jittering in physics engine?
I've got a simple physics engine that solves collisions by simply correcting the position of overlapping bodies (just circles for now) directly, as opposed to just changing the velocity or applying an ...
7
votes
2answers
779 views
Physics engine that can handle multiple attractors?
I'm putting together a game that will be played mostly with three dimensional gravity.
By that I mean multiple planets/stars/moons behaving realistically, and path plotting and path prediction in the ...
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 ...
5
votes
4answers
322 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
4answers
912 views
Is it possible to use the GPU on a mobile device to accelerate a particle physics engine?
I am interested in answers for any mobile device but I am mainly considering the iPhone and devices that run Java.
I am developing a game that relies heavily on a particle physics engine for core ...
4
votes
3answers
2k views
Why do we use physics engines for collision testing or raycasting?
There is a thing I don't understand about game engines: why it is so common to use physics engines to do raycasting or collision testing?
Say that you have a 3D scene loaded in your scene manager ...
4
votes
1answer
417 views
Problem with impulses in my physics engine
I'm currently developing a small 3D impulse-based physic engine for a CS project. It uses GJK for collision detection and is kind of stable at the moment. Nevertheless, I'm not satisfied with my ...
4
votes
1answer
770 views
How to make a 2D Soft-body physics engine?
The definition of rigid body in Box2d is
A chunk of matter that is so strong
that the distance between any two bits
of matter on the chunk is completely
constant.
And this is exactly what ...
3
votes
3answers
1k views
How can I make my main character move in a parabolic arc when jumping?
I'm entering Android game development, and I already have a computer version of a game I want to publish. The thing is, I want to make this as good as it can be. With that said, I need a physics ...
3
votes
3answers
351 views
Why does a physics engine produce different results each run through?
There are no random numbers in the engine and everything is calculated the same way. How can it happen differently each time?
This is on my own small physics engine that I made earlier that is ...
3
votes
2answers
314 views
What are the technologies that makes physics engines so good for raycasting?
again. This question is strictly related to this one so, what is the technology that makes physics engines suitable for raycasting? It is a particular data structure? Has it to do with the engine's ...
3
votes
2answers
547 views
What other components would one have to combine with Ogre 3D render engine to make a full fledged custom game engine?
I have heard that Ogre 3D is not actually a game engine, rather it is a 3D render engine. I have also heard people claim that one can piece it together with other components (engines?) to create a ...
3
votes
3answers
889 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
votes
1answer
3k views
How do I integrate bullet physics into my game?
I downloaded the release file found here, but I'm just not sure where to start. In my game I have a number of oblongs and a sphere, I want all of these to collide with one another. (They all have ...
3
votes
3answers
218 views
Physics System ignores collision in some rare cases
I've been developing a simple physics engine for my game. since the game physics is very simple I've decided to increase accuracy a little bit. Instead of formal integration methods like fourier or ...
3
votes
3answers
226 views
Semi Fixed-timestep ported to javascript
In Gaffer's "Fix Your Timestep!" article, the author explains how to free your physics' loop from the paint one.
Here is the final code, written in C:
double t = 0.0;
const double dt = 0.01;
double ...
3
votes
1answer
382 views
Design patterns in Game Physics
In the frames of a number crunching compatible programming language (say.. C++), what would be an elegant solution for adding self collision, external collision and integration step (Euler, etc.) ...
3
votes
1answer
761 views
Realistic Trajectory of a Projectile
When simulating an airplane and a missile, to get them moving in the air we apply a force in one direction. Now an airplane has wings that keeps it afloat while a missile can have fins to stabilize ...
3
votes
1answer
985 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 ...
3
votes
1answer
713 views
Cutting a body in box2d
After cocos2d, I'm looking at box2d... And I have some questions:
I was wondering how to cut a body into pieces.
How do I determine the intersection point of the body with the cut line?
Create a ...
3
votes
1answer
481 views
Havok physics with a wide range of object scales
So typically Havok works best with normal human sized objects with a gravity of 9.8m/s^2 and dealing with everything in meters.
In my Game though there will be a large variety of scales from ...
2
votes
2answers
940 views
What's the difference between a Game Engine and a Physics Engine?
What's the difference between a Game Engine and a Physics Engine? How do they work together, and what's the meeting point between them?
2
votes
5answers
7k views
which is the best physics engine for flash as3?
i am a game programmer and i use actionscript to do all my collision checking, boundary checking etc...but recently i noticed there are things called "physics engines" that help me concentrate more on ...
2
votes
1answer
165 views
RK4 integration and Continuous Collision Detection
I'm using this method to detect collision between two AABBs. The algorithm is simple, fast and works great. It uses the relative velocity between the two objects to calculate TOI. This works fine with ...
2
votes
1answer
143 views
Bounding volume hierarchy - linked nodes (linear model)
The scenario A chain of points: (Pi)i=0,N where Pi is linked to its direct neighbours (Pi-1 and Pi+1).
The goal: perform efficient collision detection between any two, non-adjacent links: (PiPi+1) ...
2
votes
1answer
178 views
Realistic 2D Planetary Physics Engine?
I'm doing a spaceflight simulator in C++ (using Allegro 5), and I realised that I could just use a physics engine instead of writing my own physics.
So that's what I'm doing.
Since this is going to ...
2
votes
1answer
428 views
Need help with collision detection/resolution in a 2D simulation of 'worm-like' creatures
(originally posted this on regular stack overflow, somebody pointed this forum out :-) )
Hi there,
I'm implementing a physics engine for the simulation of worm-like creatures. Problem is, is that ...
2
votes
1answer
233 views
JiglibX addition to existing project questions
Got a very simple existing project, that basically contains a lot of cubes. Now I am wanting to add a physics system to it and JiglibX seemed like the simplest one with some tutorials out there.
My ...
2
votes
1answer
658 views
Converting 2D Physics to 3D
I'm new to game physics and I am trying to adapt a simple 2D ball simulation for a 3D simulation with the Java3D library. I have this problem:
Two things:
1) I noted down the values generated by the ...
2
votes
3answers
808 views
What's the best open source physics engine to use with JOGL?
I have a past with jbullet but the existing jogl compatible sources and demos seems uncompleted. I have managed to implement it to an extent but still looking for a better documented engine with more ...
2
votes
1answer
153 views
Bullet physics: how to make a soft body “static” (kind of)?
I'm fairly new to Bullet and started using it a week ago. I mainly played with rigid bodies and everything works as expected but now that I also need to add soft bodies into my simulation, things got ...
2
votes
0answers
136 views
Inverse Dynamics How to
I have some motion capture data (kinect) that records all body joints (32fps) and I want to take particular positions (for example when a person moves both of his hands up in the sky in celebration ...
1
vote
3answers
566 views
Need Guidance Making HTML5 Canvas Game Engine
So I have some free time this winter break and want to build a simple 2d HTML5 canvas game engine. Mostly a physics engine that will dictate the way objects move and interact(collisions, etc). I made ...
1
vote
2answers
387 views
What is a “solver” in a physics engine?
I am self-taught and have successfully coded simple collisions of planes, spheres, rays and up until interactive cloth simulations so I do have some basic sense of which part of the physics goes where ...
1
vote
3answers
182 views
What different ways are there to model restitution in a physics engine?
In my physics engine I give a body a value for restitution between 0 and 1. When two bodies collide there seems to be different views on how the restitution of the collision should be calculated. To ...
1
vote
2answers
434 views
Entity manager loop opinions
This days I'm refactoring code and one of the things I want to improve is my entity manager code. More precisely, the update funcion where entities are updated. My engine is a 2D tile based engine ...
1
vote
1answer
664 views
AndEngine Physics: Shape rotating but not updating physics effects
I was looking at PhysicsExample from AndEngine's Examples. I made the following change that I added a vertical line shape and created a fixture for it. Then I registered a rotation modifier for that ...
1
vote
2answers
110 views
Moving Sprite With Physics Frame
Normally, a physics frame in pink (see image below) gives the body for detecting hit signal. It usually either falls down or lifts up depending on the gravity orientation. The question is: Is it ...
1
vote
1answer
166 views
Stopping an object after applying an impulse or force?
I'm having a small issue where after applying an impulse or force it is impossible to actually get an object to stop, i.e. a velocity of zero.
This code is run every 1 / 60 of a second:
void ...
