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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943 views

How does matrix based game physics (collision detection & response) work?

I'm familiar with how to do collision detection and response using shape intersection tests, the separating axis theorem, and by using MPR and GJK with minkowski sums and support vector defined shapes....
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1answer
560 views

Why is the drag force multiplied by the inverse normalised velocity vector?

In pure physics texbooks, I'm seeing this formula to calculate fluid drag force: It is clearly stated that it should be opposite to the velocity. Now to me that means, in pseudocode: ...
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245 views

Cloth effect to boned model for XNA

I'm currently working in virtual dressing project using kinect. I'm using a dress model with bone created in blender and added that to xna, placed on the customer and controlled the product movements ...
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1answer
234 views

Rigidbody physics concept: Why translate collision shape on-the-fly instead of mutating it?

Crossposting at https://stackoverflow.com/questions/29993547/rigidbody-physics-concept-why-translate-collision-shape-on-the-fly-instead-of-m I've spent some time going through physics engine's ...
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3answers
11k 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 ...
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0answers
451 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
47 views

How to discern boxes and spheres when importing from fbx

I can import scene from FBX file into my engine, and i want spheres, boxes and capsules to be imported as colliders. So, how i can check if imported instance is one of them? Thanks.
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3answers
188 views

Do I need to learn any physics if I use a physics engine? [closed]

Complete novice out here. Of course I know basic physics like mass and inertia. I don't want to make an engine I just want to make a game and use a physics engine made by someone else. Do I need to ...
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0answers
111 views

p2.js physics engine behavior on Heightfield

I am writing a small game consisting of a 'ragdoll' character riding a skateboard. I have created a 'skateboard park' with some ramps and a jump. I am using a 'heightfield' object as the ground. ...
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1answer
408 views

Irregular oval collision detection

I am using a physics library based on the Bullet physics engine. How do I create an egg shaped object or a cylinder where the width differs from the depth (i.e. with an oval shape)? I'm not looking ...
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0answers
237 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
704 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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2answers
289 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
554 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
1k 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
95 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 ...
13
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1answer
21k 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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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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0answers
193 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
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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1answer
459 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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1answer
2k 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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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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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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1answer
869 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
183 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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2answers
499 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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6answers
21k 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 ...
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3answers
11k 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 ...
2
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1answer
501 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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3answers
9k 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 ...
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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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1answer
8k views

3D open source physics engine suitable for mobile platforms (Android and iOS)

I have made some research and found that bullet, ode, newton and some others are open source physics engines that should be portable enough (but I have never tried to comile/use anyone of them on ...
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3answers
299 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 ...
2
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1answer
786 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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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
1k views

What's the best open source physics engine to use with JOGL? [closed]

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 ...
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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
261 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 ...
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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
3k 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
472 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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1answer
644 views

Want to develop my own primitive physics engine, don't know how to start with its high-level architecture. Suggestions? [closed]

Few years ago I tried to make a simple 3D game - billiards. Completed like 50%, stuck with physics. Basically, I only need to calculate balls rolling over flat surface, but it would be nice to make ...
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2answers
262 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
261 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
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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2answers
836 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 ...
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1answer
8k 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 ...
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1answer
558 views

physics model simulation

I am building a game for which I want to simulate certain rigid body dynamics.Could someone suggest me some engines which work on Ubuntu.Also as I have dont have much time to implement it,so it would ...