Relating to the motion of objects through space and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.

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Invalid AABB aabb

Invalid AABB aabb UnityEditorInternal.InternalEditorUtility:CalculateSelectionBounds(Boolean, Boolean) I've got this error ...
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1answer
139 views

Path following with Asteroids-like movement. Time to complete path

I'm currently learning about how to do this, but it's best to post the problem beforehand. (posting on Physics and GameDev, as you guys know your math) It's quite difficult to explain. This specific ...
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3answers
195 views

Colliders for moving inside a spaceship when the whole spaceship is made of a single mesh (in Unity)

I've begun to study a unity engine in one purpose: I have a great multi player game idea! The main essence: In space there are two (or even more) huge spaceships with crew consisted of players (all ...
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2answers
90 views

Player in Spaceship

I want to realize space game on Unity3d engine. There are some huge spaceships in the void. So, I want players flying in space in weightlessness, but when they go inside any spaceship, they will be ...
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1answer
109 views

How to implement angled surface?

I'am trying to implement 2D platformer game inspired by N game. But the problem is I have no idea how to implement something like this: I have two ideas of how this could be implemented but i ...
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1answer
323 views

How To Program a fully controllable spring (Damped) motion

i'm working on a project that needs realistic 2D Animation, none linear motion you might say, i have tried many things such as Hermite Curve and a few other motions and in the end Spring Motion. ...
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1answer
81 views

Box2d jetski on water

At the moment I am trying to code a 2d game in java, where a jetski is riding on water. If you press on the screen the jetski should dive down and jump back up on release. How do I have to do this in ...
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1answer
249 views

Gravity and Jumping in Clickteam Fusion 2.5

So I'm currently building a bare-bones functioning game that involves simple platforming. Quite literally a box moving left and right and jumping. I'm using Clickteam Fusion 2.5, and I know there's an ...
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30 views

AABB in OpenCL not working correctly

I have this really simple OpenCL kernel. The values get in correctly and get out correctly. So the error must be somewhere in the kernel. All the parameters are float arrays. pos rot vel and aPos aRot ...
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48 views

How velocity impacts on CCSprite in Cocos2d Chipmunk?

I am in need of the basic understanding of how velocity changing works? i.e. how CCSprite is able to jump at particular height when some velocity is set? Let me give you an example on which I am ...
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1answer
213 views

PhysiJS and objects on top of moving objects

Using Physijs which uses ammo.js. I am attempting to simply place a sphere on top of a box, the box is moving back and forth and I want the sphere to move with it while also being able to move on top ...
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3answers
688 views

2D Physics friction on a moving platform?

I have a few basic platforming mechanics going on in this scene. I have a prefab platform with an animation that loops back and forth between two different x positions, but does not begin looping ...
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1answer
62 views

Why are my Hello World Box2D project's collisions off by twice the size of my boxes?

I've been implementing Box2D into my engine but have run into a snag. I decided to rebuild the helloworld project inside of my own engine (it is almost identical), of which I will snip here in a ...
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1answer
73 views

Game Sprite Motion

I really like the effect that I see in this video of Mario Party 10 Jewel Drop (at 2:40). It occurs when the four green orbs join together. You'll see a four items with long trails move to the top ...
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2answers
188 views

why is my enemy AI is on air while moving?

In Unity3D I have created an enemy AI and applied a script for it to move and chase the player. But when moving, the enemy hovers in the air. My character also does not have rigidbody and he just has ...
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3answers
75 views

Need help with physics 2D Unity

I'm making a 2D game in Unity. Basically there's just a rocket that goes where ever the user touches. With the code that i have right now, the rocket instantly rotates towards the point and moves ...
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2answers
564 views

Preventing a Combination of Rigidbody Jump Force & Bounce Magnitude in Unity3D

I'm building a fairly simple marble racing game in Unity3D. The ball is a 3D physics object that moves only on the X and Y axes. It has the ability to roll left and right, and to jump. Pretty basic ...
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1answer
91 views

Need help with Physics

I'm using Unity to develop a game. Basically i want the player/rocket to follow a point on the screen where user touches. But It's based on physics. Force must be added when user touches somewhere and ...
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1answer
161 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 ...
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1answer
128 views

Sliding DOOM style collision resolution against arbitrary 2D geometry

I've been working on a HTML5 canvas raycasting engine for the web browser, with the end goal of making a simple FPS game in the style of the early 90s. The engine sits somewhere between Wolfenstein 3D ...
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1answer
89 views

Kinematic equations script fail

I added the kinematic equations to my code and now none of it works. I get the error rigidbody.torque assign attempt for 'Enemy' is not valid. Input torque is { 0.000000, NaN, 0.000000 }. ...
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1answer
65 views

Move Ball to clicked direction

I have a ball as a sphere in my game and Im viewing it from top down view (birdseye). The ball is a rigid body. I want to achieve when I click somewhere on the screen, that the ball moves toward ...
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0answers
24 views

Precision problem when doing collision detection?

I've got this problem, and I don't know what may be the cause of it. I finished reading this article on sphere-triangle collision. My character (the sphere) stops before it reaches the triangle, and ...
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1answer
127 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: fd = ...
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1answer
64 views

Objects phasing through each other in physics engine

I'm writing my own physics engine right now (following this tutorial), but I'm running into some problems. Sometimes on collision, objects will just phase through each other instead of bouncing off of ...
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1answer
341 views

How do i move a 2D object with angle and speed variables in unity?

I want to move an object with a certain angle and speed, is there a was to set this as an initial velocity so that it is still possible for the object to collide and bounce of other objects using its ...
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0answers
81 views

Why doesn't my orbit form an ellipse?

I'm playing around and trying to build an orbit simulator. Unfortunately, it isn't working out to well. Instead of forming some sort of elliptical orbit, I get this: Here is the code I'm using to ...
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2answers
239 views

How do I separate physics from framerate?

Skyrim (Creation Engine / Gamebryo) is a prime example of a game that has its physics tied to the framerate for which it has been heavily criticized, because if you disable vsync / have a > 60 HZ ...
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2answers
243 views

How to calculate faces involved in collision (Separating Axis Theorem)

I have a game engine created in javascript (https://jsfiddle.net/4gqsq8wf/) which uses collision detection via the Separating Axis Theorem. Currently, it does not have any means of resolving velocity ...
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2answers
83 views

Using fixed timestep and interpolating states makes physics fall behind one frame. Does that affect responsiveness?

The title says it all, but let me build more into the question: I suppose everyone by now knows the Fix Your Timestep article, and its proposal to free your physics engine steps from your rendering ...
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2answers
73 views

How to get a pleasant path accelerating to a point

I am having trouble moving an object to a target position with a maximum acceleration limit. If i just accelerate towards the target the object will fly in a doughnut a few times before hitting the ...
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1answer
12 views

Is GetFixtureA() of b2Contact guaranteed to return the body on which GetContactList() was called?

For example, in the code below, will the assert ever fail? for (const b2ContactEdge *contactEdge = playerPhysicsBody->GetContactList(); contactEdge; contactEdge = contactEdge->next) { ...
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1answer
71 views

How can I determine “exact moment” of collision with ray casting?

I'm currently brainstorming how the physics for my game engine is going to be handled. It's top down and I'm thinking of using ray casting for collision detection. I've reached two potential problems ...
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1answer
131 views

Organizing movement, collision detection, and collision resolution

There's many articles on the internet focusing on how to implement movement, collision detection, or collision resolution. What I'm wondering is how to put them together, specifically in what order to ...
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1answer
94 views

Applying velocity to objects in a specified direction

How to apply velocity to a particular direction? Data which I have: object position (P1) destination (P2)
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65 views

Static blocks - phaser isometric plugin

I'm creating isometric game like minecraft with phaser engine with rotates isometric plugin and I need colliding with player, but when I turn off physics, blocks is not static. Question: How to ...
6
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3answers
282 views

Change in direction should slow down object and accelerate in new heading (2D grid-based)

I'm trying to implement some sort of faux space physics in my 2D game. I have a top down view of my space ship. You can change direction and set a speed up to a maximum which then accelerates the ship ...
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1answer
141 views

Using Physics.Raycast inside OnCollisionEnter2D function

void OnCollisionEnter2D(Collision2D collision) { foreach(ContactPoint2D contact in collision.contacts) { RaycastHit raycastInfo; ...
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1answer
146 views

Using Farseer Physics, how can I get objects to bounce at the correct angle

I am using the Farseer Physics engine in my MonoGame project. I have static walls which have "body" friction 0 and "body" restitution 1. I have dynamic objects, which are circles, with "body" friction ...
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1answer
253 views

How to detect collision position and that position's texture color in Unity?

I have a prefab and I use Circlecollider2D for physics operations. I want to detect the color of the contact position of the collided objects ? Is is possible by using Unity's collider classes ?
4
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1answer
246 views

Rotate a rigid body not around its centre of mass

I have a rigid body (a boat) whose centre of mass is towards the front of the object. However, this makes the rotation look strange as the rudder that is turning the object is at the back of the boat ...
5
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1answer
354 views

Circle Collision Resolution and Angular Momentum

I have a 2D engine working pretty well that involves rectangles and circles. I just reworked parts of the collision detection/response system for better handling of angular speed/momentum. The ...
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1answer
90 views

LOVE Physics - Joint Stretching

After asking a similar question yesterday I've come across another problem with using joints in box2D / LOVE and trying to create a weighted chain. Everything is set up as follows, I've tried to ...
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1answer
362 views

How to get plausible platformer physics with Farseer on MonoGame/XNA?

I am creating a 2D Vectorial (made of polygons, not tiles !) platformer using MonoGame and Farseer Physics Engine. Everything works perfectly, except the movement of the character which doesn't feels ...
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1answer
153 views

LOVE Physics - Breaking Joint Chains (LUA / Box2D)

Wasn't sure whether to post here or on SO so please move if needed. I've been having a look into the box2D physics API provided by LOVE to try and create a swinging flail or weighted rope but I'm ...
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0answers
44 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 ...
3
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1answer
137 views

Box2d Body to follow mouse movement

I am trying a box2d body to rotate following the mouse. Here's an image to clarify what I mean. The red and blue circles are current point of the mouse and the body (of corresponding color) ...
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2answers
504 views

Testing Unity 2D Physics

I am looking to push the 2D physics in Unity to the extent where when so much is going on that there becomes noticeable lag in a game. This is for testing purposes, so that when so much is going on ...
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2answers
391 views

How can I calculate the future position of my moving object?

I'm relatively new to games development and I have a 2D game where the playing area is an enclosed rectangle with width w and infinite height. In the playing area there is a ball. A gravity force of ...
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1answer
412 views

2D Collision response - rotating, moving polygon hitting a wall

I'm trying to bounce a polygon that has both velocity and angular velocity off a (immovable) wall when one of the vertices collides with it. I can detect the collision, and I've worked out how to ...