Questions tagged [physics-engine]

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

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1answer
587 views

How do I run a physics simulation in the background, to determine 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 to ...
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0answers
222 views

Storing rigid body collision shapes in local or world coordinates

I'm writing the beginnings of a lightweight 2d rigid body engine (in javascript, as a hobby project), and i'm debating whether to store collision shapes in local or in (updated as needed) world ...
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1answer
2k 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 ...
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2answers
268 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 ...
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1answer
482 views

Farseer - Difference between Position, GetLocalVector, and GetWorldVector

I have used Box2D extensively, and am used to just calling body.GetPosition(). But Farseer does not have this. Instead it has a property ...
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1answer
970 views

Lunar lander: How to calc acceleration in each step

I'm trying to make a lunar lander simulator. I'm going to use a simple Euler integration. AFAIK all I've to calculate is the acceleration in each step, and then I should be able to update velocity and ...
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1answer
86 views

Check every body's position and delete or not (box2d performance specific)

I have a simple game with a platform (a ground that's not infinitely long). During the game I have about 10-30 balls on average that'll fall off the platform. There's gravity so I think they'll keep ...
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3answers
1k 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 ...
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0answers
192 views

Mobs living in the physics engine

So, yeah. Mobs (including, and indeed especially, the player), physics engine running (cannon.js), first-person perspective, fairly low-poly-count world because I'm targeting WebGL. I'm trying to ...
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1answer
1k 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 ...
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3answers
7k 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, ...
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1answer
3k views

animating roulette ball

I'm trying to achieve something like netent's roulette (which is a great product in my opinion). It's going to be implemented in html5. I wonder which path should I take to have such a great ...
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2answers
1k views

How to deal with pushing objects out of collision in a physics engine

I'm developing a 3D physics engine (I know, I should use one of the many good existing physics libraries, however my collision detection is optimised for objects with highly ordered highly complex ...
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3answers
2k 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 ...
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1answer
177 views

Is there any physics engine for XNA? [closed]

I am an XNA game developer. I am now starting to develop physics games on XNA but the problem is that I don't know about any physics engine desinged for XNA. Please if you know about it kindly help me....
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1answer
1k 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 ...
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1answer
761 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 ...
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2answers
181 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 ...
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1answer
452 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 ...
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2answers
447 views

limiting jump forces to achieve a maximum jump height [duplicate]

A player and the world are modeled using a physics engine. Jumping is modeled by applying a vertical upward force to the player's physics body when the jump button is pressed. The upward force is ...
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3answers
10k 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 ...
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0answers
433 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 ...
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1answer
674 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: ...
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1answer
456 views

What physics engine support force fields and bodies represented as points?

I need a game engine that supports force fields in 2d or 3d, but suitable for 2d calculations, like bullet. Each body I want to simulate is represented as a set of points. Each point has positive ...
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1answer
683 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 ...
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3answers
1k views

Need Guidance Making HTML5 Canvas Game Engine [closed]

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 ...
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2answers
403 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 ...
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1answer
810 views

How to make a stack stable? Need help for an explicit resting contact scheme (2-dimensional)

Previously, I struggle with the sequential impulse-based method I developed. Thanks to jedediah referring me to this paper, I managed to rebuild the codes and implement the simultaneous impulse based ...
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4answers
607 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 ...
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1answer
9k views

How to achieve highly accurate car physics such as Liveforspeed?

Liveforspeed is a racing simulator, there is amazing amount of realistic physics. for example, tires get warm, tire actually deforms when you turn corners. You need to play this game with a mouse at ...
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3answers
1k 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: ...
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2answers
6k 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?
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1answer
738 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 ...
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1answer
1k 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 ...
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3answers
295 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 ...
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4answers
1k 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 ...
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3answers
10k 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
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2answers
543 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) vs....
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1answer
1k 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.) ...
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2answers
2k 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 ...
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3answers
5k 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 ...
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3answers
468 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 ...
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2answers
2k 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 ...
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1answer
361 views

How to implement a physical with perspective effect on Android?

I'm working on a project that looks like PaperToss. Instead of tossing a page, you toss a coin. Suppose that I have a coin put in three-dimensional that have coordinates at A(x,y,z). I throw that ...
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2answers
261 views

Game with static scene and bouncing balls. How to?

How to make a game with a static scene and balls that can bounce on it? What is used for this, generally? Physics engines? Even if this is a simplistic example?
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1answer
253 views

How to pin a body in case of collision in Box2D or Farseer?

I'm trying to get an understanding for the Box2D/Farseer physics engine by implementing a small air hockey simulation. There, I have the problem that the CPU player attacks the puck, kicks it, but ...
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1answer
19k 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 ...
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1answer
1k views

what is the absolute simplest way to add physics to a simple 3D game

This physics does not have to be very complex at all. There are a number of rectangles and one ball, all of which have the appropriate bounding volumes constrained to them, it would be great if the ...
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3answers
6k views

2D games on Unity and collision detection performance

I'm developing a 2D game for the iOS platform. I have seen a lot of packages on asset store that makes 2D asset creation for unity easier. I have narrowed my selection to just 2, 2d toolkit and ex2d. ...
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2answers
806 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 ...