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.

46 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
4
votes
0answers
378 views

3D Physics Engine Collision Response: Solving Simultaneous Collisions via equation

I have been implementing a basic physics engine for a small game project I'm working on. It has very specific requirements, so I decided to try and write my own physics engine to meet them. I found ...
3
votes
0answers
72 views

Faster convergence in a physics engine

I've got my hands on the first edition of the book Game Physics Engine Development: How to Build a Robust Commercial-Grade Physics Engine for your Game by Ian Millington. Because I didn't really know ...
3
votes
1answer
326 views

Rigid body falls through static mesh even though collision is detected

I'm using Jitter Physics to create a game. For testing, I have ball (a spherical rigid body) falling onto a small box-like mesh. The problem is that the ball falls straight through the floor, even ...
3
votes
0answers
136 views

Integration of Game Loop + Physic Engine : when to delete objects?

How to manage code around physic engine, when a game object should be deleted? I will use a tiny game as an example:- 1st iteration of development I have a very simple game with 1 character (Jumper)...
3
votes
1answer
682 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: ...
2
votes
0answers
215 views

Bullet Physics Scaling rotational part of 6DoF Spring Damper

I am currently trying to scale up my setup (consisting of two rigid bodies connected by a btGeneric6DofSpring2Constraint) to fall within the suggested dimensions for a concise simulation. In order to ...
2
votes
0answers
222 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 ...
2
votes
0answers
108 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. ...
1
vote
0answers
39 views

Time complexity of solving constraints in physics engine

Erin Catto mentioned in a talk that solving constraints precisely requires cubic time and quadratic space. What algorithm is he talking about when he mentions cubic time? pdf of slides with following ...
1
vote
0answers
22 views

Real-time 3D Scene-reconstruction into Physics Engine

I am trying to create a game where the user scans the room using RGBD camera and reconstructs 3D scene. This scene would be integrated into physics engine, after an object recognition algorithm tells ...
1
vote
0answers
68 views

How do I prevent falling tiles from bouncing on each other in my match 3 game?

I am working on a match 3 game in Unity. The tiles have a RigidBody2D in dynamic mode and a BoxCollider2D. When a match occurs ...
1
vote
0answers
27 views

Polygon doesn't bounce enough in edge-ground collisions (but it does in vertex-ground collisions)

I'm currently making a (basic) physics engine in Python in which I want a polygon to bounce off the ground (\$y=0\$). When a vertex hits the ground, I apply the (linear) impulse $$\overrightarrow{P}...
1
vote
0answers
62 views

Is it better to combine or leave alone 2D polygons

I'm making a modular system for a 2D spaceship arcade like game, the user builds their own ship with equilateral triangles to make more complex shapes. When the ships are small it's no problem, but as ...
1
vote
0answers
102 views

Bullet physics convex hull center of mass

I am trying to make a convex hull collider for bullet physics. I am using BulletSharp.CompoundShape and BulletSharp.ConvexHullShape. This is model of a chair in unity with rigidbody and convex mesh ...
1
vote
0answers
23 views

Deformable meshes based on torsional spring

I am trying to learn physics-based animation thanks to the book "Foundation of Physically-Based Modelling and Animation". They introduce the mass-spring model for deformable meshes. Although making ...
1
vote
0answers
59 views

Modern way of getting points within a distance?

I'm making a game engine, and some components may want to interact with others based on distance. Currently, the component registers an update listener which runs on a loop, then it checks the ...
1
vote
0answers
39 views

Gauge vibration

Hello guys Im programming a gauge animation where there is a needle that points to certain values lets say each value equals to the amount of degrees the needle has to rotate to reach said value ...
1
vote
0answers
40 views

Weird issue in collision resolution of non-static bodies

I'm a bit of a beginner in engine development, so I decided to write my own engine from scratch so I could learn more about what happens under everything. I've been progressing fairly well, except ...
1
vote
0answers
501 views

2D physics engine: Impulse based collision response with contact point manifold

I'm implementing a 2D physics engine where collision response is based on impulse computation. I'm going to first expose the context, then the problem, and finally the questions. Context Simple ...
1
vote
1answer
212 views

Calculating real time moment of inertia around arbitrary axis in 3d

I have a 3d rigid body consisting of multiple triangles forming a closed mesh. I know how to calculate the moment of inertia around an arbitrary axis by splitting up the mesh into simpler shapes and ...
1
vote
0answers
60 views

Is this a correct way to solve contact?

Hi there, I'm learning the impulse based physics engine these days. Can someone please check my image about solving a contact( a sphere resting on ground) , and please let me know where is wrong. ...
1
vote
0answers
182 views

Physics fixed time step with client/server games

I'm trying to make a 2D platforming multiplayer game with client/server system. I want to use Node.js and Phaser for the display. I read a lot about fixedTimeStep : http://gafferongames.com/game-...
1
vote
0answers
121 views

(UE4) Simulate physics breaks timeline animation

I'm using timelines to animate my boat object, which does not have any limbs. So all I need to accomplish is rotation and a little movement. However, when the player dies, I need the boat to sink ...
1
vote
2answers
545 views

How to get the point of collision in Separating Axis Theorem?

I'm interested in the relatively precise point (not line) of collision for calculating angular velocity on impact for use in a impulse calculation. At first I thought, perhaps naively, that I could ...
1
vote
0answers
410 views

How can I create click and drag for a 3D Jenga game in Unity?

Essentially, I am trying to create a game that mimics Jenga. Right now I have made it so that the blocks collide with each other and have gravity, everything works very well. The one thing that I am ...
1
vote
1answer
503 views

How would joints work in an impulse-based physics engine?

I want to learn about physics engines, especially impulse-based ones. So I've followed along this tutorial to create some simple rigid-body physics: http://gamedevelopment.tutsplus.com/tutorials/how-...
1
vote
0answers
171 views

Collision Detection between two instances of the same Prefab

I am a trying to recreate the first stage of Super Mario Brothers, but I am having a bit of trouble with the collision system between Koopa Shells. I have written two different scripts in hopes to ...
1
vote
0answers
320 views

2D Platform physics system with deltaTime

I'm implementing my physics handler in my own 2D "Platform" game. My main problem is that when the timestep ( deltaTime ) changes, maybe to some tiny lag spike or something like that, the running ...
1
vote
0answers
523 views

Bullet Physics: Applying a force at the point of collision

Suppose I want to simulate some kind of gripper with two "fingers" (such as pair of pliers, or two-fingered robot hand), picking up an object from the ground. Both the gripper and the object are ...
1
vote
0answers
223 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 ...
1
vote
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 ...
1
vote
0answers
884 views

Joint constraints in PhysX

I'm trying to use PhysX for my physics engine. I'd like to use spherical joints, but I'm having trouble with the constraints. All of the examples that I've found refer to SDK v2.8. I'd like to ...
0
votes
0answers
14 views

Elastic collisions between cubes and walls

I have a simple scene with two cubes and walls as shown bellow. The right ball starts moving with initial instant force along the x-axis and collides with the first ball and reflect off a vertical ...
0
votes
0answers
52 views

how can I visually compensate for latency in a diep.io style game

implementing extrapolation using linear velocity, orientation and position like on here gafferongames.com/post/state_synchronization/ I'm a little confused if I want to extrapolate from a known ...
0
votes
0answers
42 views

Simulating circular motion with gravitational forces in Unity2D

I am currently messing around with a game where you control a black hole and use its gravity to fling planets at targets. I have the gravity calculations working pretty well when the planets start out ...
0
votes
0answers
34 views

RigidBody Collision Handling with Verlet Integration

Hi I'm reading the Jakobsen Paper "Advanced Character Physics" which explains how the verlet integration along with a tetrahedron (4 particles) can form a structure usable for rigidbody (with 6 length ...
0
votes
0answers
40 views

Calculating approximations of support/forces between objects in Unity

I'm looking for ways to calculate how much a given object supports another in a scene. For example, imagine a box is on a table. In this situation we may say the table provides support to the lamp (...
0
votes
0answers
26 views

Numerical errors in Player collision offset causing player to fall through the ground the next frame, how to avoid?

I'm trying to implement player physics with arbitrary objects, in this case, a bunch of cubes. I wanted to add a "floor" so in my cube collision function, I added the following following lines: <...
0
votes
0answers
40 views

Implement MMO like character movement without a full-fledged physic enginge?

Question: How can I implement World of Warcraft / Guild Wars 2 / etc like player movement, including jumping, without using a full-fledged physic system for my multiplayer game since players only ...
0
votes
0answers
58 views

Solve Constraints with linear factor of 0 in Bullet Physics

In my code I need to set the linear factor for velocity to 0 (sometimes). For example, game->rigidBody->setLinearFactor(btVector3(0, 0, 0)); When this is done,...
0
votes
0answers
37 views

Full energy transfer between two identical objects

I'm trying to simulate a game like billiards / shuffleboard / curling where two objects collide and under a perfect direct hit all energy is transferred to the second object. Both ...
0
votes
0answers
114 views

Unity like RigidBody physics in PyGame

I am trying to make game but first I want to make simple simulator. The goal is to have a ball fall onto a surface and then roll off the edge. Here is my code: ...
0
votes
1answer
183 views

Physics engine and rigidbody sleep optimization

I am trying to add sleep optimization to my little physics engine(just for learning). I use SAT for collision detection that returns penetration normal and depth without contact points. Objects are ...
0
votes
1answer
24 views

Having trouble with btGeometryUtil::isPointInsidePlanes

I'm in the process of parsing a BSP file to create btConvexHullShape objects for each brush. I've seen a few examples of how to do this on Github and they all use the getVerticesFromPlaneEquations ...
0
votes
0answers
88 views

Which Box2D-like physics engine parameters need pixel conversion?

The official guide does not have any useful details on the matter: http://www.box2d.org/manual.html Position is an obvious one. What about velocity? Density? Anything else? Update: the context is ...
-1
votes
2answers
77 views

Problem making wave animation

I want to simple wave-like animation using mesh. I thought that it would look like a wave if there would be a point at the middle of the mesh and change z axis of that point, and after this I change ...