Software for simulating physics like collisions, forces, mass, joints, motion etc. Examples of physics engines are PhysX, Havok, Bullet and ODE.

learn more… | top users | synonyms

17
votes
7answers
17k views

What are some known 2D/3D physics engines for XNA? [closed]

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 ...
16
votes
6answers
9k 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 ...
15
votes
6answers
4k 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 ...
14
votes
1answer
2k 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 ...
13
votes
4answers
602 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 ...
12
votes
3answers
2k 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
2k 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
4k 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 ...
8
votes
3answers
1k views

Are collision detection always O(n^2)?

Are physics engine able to decrease that complexity, for example by grouping objects who are near each other and check for collisions inside this group instead of against all objects ? (for example, ...
8
votes
3answers
2k 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 ...
8
votes
1answer
293 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 ...
8
votes
3answers
388 views

Make fast thing look slow (Box2D)

I'm working on a game that you control a trebuchet to throw balls to the opponent. It's like a game called 'Medieval Siege'. When the trebuchet is swinging its arm, player need to seize the best ...
8
votes
2answers
1k 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 ...
7
votes
1answer
558 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
276 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
4answers
612 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 ...
6
votes
4answers
1k 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
3k 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 ...
4
votes
3answers
3k 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
560 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
1k 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 ...
4
votes
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
votes
1answer
920 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
3answers
392 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
1answer
6k 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
2answers
611 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
2answers
340 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
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
votes
3answers
583 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
3answers
252 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
1answer
152 views

Calculating impulse with multiple collision points

In my amateur 2D rigid body physics engine for a game I react on collisions between two bodies with an impulse j (formula 11) as explained here. To calculate this impulse I need one contact point P ...
3
votes
1answer
571 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
388 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 ...
3
votes
1answer
988 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
642 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
2k 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
2answers
161 views

Replicating no. of sprites without letting the app to slow down and crash

Is it possible that if I'm making a a simple drag-n-drop game, does making a new sprite via constructor with texture as a parameter makes the game slower and depletes more memory until it crashes or ...
2
votes
1answer
127 views

How to run physics simulation in the background for possible future outcomes?

I'm designing a physics-heavy game in 3d. The core mechanic of this game is that the user gets to choose his actions based on probable future outcomes. For example - the player has a choice whether ...
2
votes
1answer
378 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
230 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
588 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
246 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
837 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
0answers
321 views

C++ FPS game collision detection with partitioning system or physics engine? [closed]

I'm working on a small FPS game (as a hobby and for learning purposes, nothing else) built with C++ in OpenGL (from scratch). Documenting online on the kind of strategy someone would approach with ...
2
votes
1answer
468 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
214 views

Inverse Dynamics How to [closed]

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 ...
2
votes
0answers
274 views

Friction due to gravity in an impulse based physics engine

In my physics engine, I'm using impulses to solve collisions. I'm basing all calculations on these equations: impulse = desired_velocity_change * mass impulse = force * time friction_force <= ...
2
votes
0answers
2k views

Good open source / free C/C++ engines/libraries [closed]

Since building a game is not about 2D anymore, I just want to build a list of the (not necessarily best, but good enough) open source software available to make games. I prefer to put emphasis on ...
1
vote
3answers
783 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 ...