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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3
votes
2answers
279 views

2D Physics: What happens with torque when center of mass changes?

Novice programmer and explorer of simple 2D physics, here. I have a simple 2D object made up of two rigid bodies connected at a fixed joint. The two rigid objects can rotate freely about that fixed ...
0
votes
0answers
23 views

Launching projectile from a “canon” [duplicate]

I'm working on "Scorched earth"-like game just for learning purpose. I can't figure out how to launch the projectile from my tank's position, with a power of X ([0,100]),at an angle of Y ([-180,180]). ...
0
votes
1answer
208 views

Rotate a plane defined by its normal and its distance

First apologies for the amount of pictures, it's a bit hard trying to explain my problem without pictures. Hope I've provided all the relevant code. If you feel you want to know about how I am doing ...
0
votes
0answers
375 views

Anti-Roll bar doesn't work

I'm making a racing game in Unity that has trucks as vehicles. For the truck movement, I'm using WheelColliders. After some testing, I found out that after a certain speed (~60km/h), turning made the ...
2
votes
1answer
187 views

Unintended sliding blocks Unity (5) physics

A game I'm working on right now relies on the Unity physics system for collisions, gravity etc. This all works well except for one strange thing. When an explosive is placed on a stone cube, it'll ...
0
votes
0answers
116 views

How can I handle ball interaction with lanes in a pinball game?

In a pinball game, how can I handle collision or constraints on the ball for convincing movement on those highway rails/tracks? I assume using physics and a mesh collider would not work, even when ...
0
votes
1answer
72 views

Dragging an object and moving it back to it's original position on release?

I'm making a small game, and I'm trying to add this mechanic where if you click on an object and move it, then you release the object it will snap back to it's original position. Currently, each ...
2
votes
1answer
70 views

How to restrict jumping to a single jump?

I'm making a VolleyBall game in HTML5 with PandaJs GameEngine and plugin is used physics and Box2D. The problem is that players can jump, but they can jump over the net with multiple jumps. I have ...
0
votes
1answer
292 views

LibGDX - Executing 2 different touchDown events in the same method

On the bottom left of my screen is a circle with an Arrow and on the bottom right is a circle with a gun. If the player is in jetpack mode and the Arrow "button" is clicked he flies like flappy bird ...
0
votes
1answer
144 views

How to reference the right object in Unity

So, I'm developing this small 2D project where I have a sphere that detects if objects get close to it from three different directions. I have successfully found a way to detect if an object ...
1
vote
1answer
157 views

Using Box2D for soccer physics

I've learned quite a bit of Box2D and I've succeeded basic stuff concluding ball physics. I want to implement 'opposing forces', as the character kicks the ball with a certain strength, with the leg ...
0
votes
1answer
375 views

Getting distance between point of an object and another object in Unity

First, I'd like to apologize because this is a very basic and repetitive question, but I am completely new to game development. I understand that I can find a distance between two objects using: ...
0
votes
2answers
701 views

Realistically drivable car

I want my car to be realistically drivable (like in real life...) Unfortunately all I did so far is Rotate the whole vehicle using A and D; and AddForce in forward-backward direction using W and S ...
2
votes
3answers
979 views

How to implement accurate frame-rate-independent physics?

So, I have been working on a project for a while now and recently stumbled across a problem: The common approach to frame-rate independent physics is to either use a fixed update interval (ie. Unity) ...
0
votes
1answer
117 views

How do I get realistic sliding contact between objects in a voxel grid?

I have a 3D grid of voxels in my game. Entities walk around with simple physics that represents them as an axis aligned bounding box with velocity, mass and acceleration. The way I'm doing collision ...
1
vote
1answer
672 views

Cocos2dx+Chipmunk: Fully elastic collision between moving bodies

I'm using Cocos2dx and the built in Chipmunk physics engine, and currently I've got my PhysicsBodys' materials set up with: Density=0 Restitution=1 Friction=0 in order to get fully elastic ...
0
votes
1answer
57 views

How to move a car model on a plane?

I want to create a 3 dimensional car game. But i have a problem in moving a car in other directions and accelerating. I have a car model and a road model placed appropriately. To move car forward, I ...
1
vote
1answer
128 views

What is the purpose of integration in physics engines?

All online resources seem to assume that you know what this means and/or state that this is related to object movement in some way. How does this differ than just position.x++ and position.y++ and ...
2
votes
1answer
252 views

Immovable object impact physics

I am trying to do some physics calculations from scratch, and as a result am creating a small bouncing ball example. However, I have some issues getting correct results from my impact physics when the ...
0
votes
1answer
40 views

Box2D: Making it Determinsitic?

From articles on the web, I found that floating point math generally has accuracy of at least 6 digits. With this in mind, is it possible to make Box2D which uses floats fully deterministic through ...
2
votes
1answer
563 views

Dynamic body in Box2D with fixed position

I need to fix the dynamic body position so that it would not rotate and would not move even if there are other forces, collisions and so on. Let me first explain why I need this. I have a dynamic ...
1
vote
1answer
64 views

Finding the side of a shape a ray intersects

For some simple 3D shapes (cubes, prisms) how can I determine which side a ray intersects, knowing the direction of the ray, and the normals of the shapes' sides. I thought of using plane ...
0
votes
1answer
70 views

Physics-based rotation with an array of pixels

Say I have a simple system, that has a large array of pixels with their own weight, velocity, coordinates etc. (by using classes) if each of those pixels can be connected to 4 other pixels (top, ...
1
vote
0answers
21 views

Java JBullet models not colliding [duplicate]

Hello I wan't to do model collsion in JBullet but that don't won't to work. Models look like have some invisble holes. Here the code for creating collsion shape: int triangles_count = (int) ...
0
votes
2answers
108 views

Why does this simple if-statement that checks my main characters state never get called (Java/LibGDX)?

Been working on this for a while - basically I want my player to perform a front flip when he jumps (screen tap -> player jumps). I wrote the animation class Animator (extends Player implements ...
3
votes
1answer
258 views

Frame independent buoyancy using Substepping

I am having trouble with a frame independent buoyancy force using substepping in Unreal Engine 4. The original problem (which I am attempting to solve using substepping) is that when you apply a ...
0
votes
0answers
57 views

Stuck on a steering problem

i'm building a car game, and currently working on the steering. i would like to change the motion of Z rotation so that the car rotates around the Z axis when the wheels are turned. I can't set the ...
-1
votes
2answers
184 views

Does conservation of energy exist in most physics engines?

The reason I am wondering, is because while trying to create gravity around a point in the physics game I am creating, I wondered "If I create an object in the middle of the screen, where would the ...
0
votes
1answer
132 views

Relative movement in Box2D (keep object from falling off planet)

I'm creating a game with planets orbiting around a sun, like this: The brown square is the earth, rotating around its center and around the sun. The yellow square is the sun, which doesn't move. Now ...
0
votes
2answers
398 views

How do I derive an appropriate acceleration value for my game?

I am creating a Flappy Bird clone from this tutorial. I have a question about acceleration in libgdx. The author assigned the bird a constant acceleration vector in the constructor of the bird ...
1
vote
0answers
90 views

Farseer: Friend/Foe Collision - cannot push foes but friends

we are using Farseer in our project and I try to find a setup to achieve the following quite complicated collision behavior: Friendly Units can push each other aside. However, the push should be a ...
2
votes
2answers
704 views

2D Boat controlling physics

I'm working on a top-down 2D boat game with Unity3D. I couldn't able to understand how to implement physics of rudder controlling. My physics knowledge is not enough to think how rudder dynamics work. ...
0
votes
3answers
188 views

[Unity]Avoid boucing when ground move down

I have a sphere & a quad, when the quad move down, the sphere fall after and bounce back continuously. I dont want to change my project setting like bounciness, gravity,mass and I need the sphere ...
1
vote
1answer
87 views

Lots of bouncing balls sink into each other [closed]

I'm trying to model a system that simulates an arbitrary number of bouncing balls with some gravity. So far I've come up with a solution that can be seen here: ...
0
votes
2answers
324 views

Unity2D Collision Issue

I have a crate setup (in pic below) with a rigid body component, box collider and 3 circle colliders(they allow me to push the crate most of the time without getting stuck on the floor textures which ...
-1
votes
1answer
295 views

2D bouncing formula doesn't work properly

am new to unity, and i am trying to create a bouncing ball, so i've did many researches about bouncing realted physics and i found a formula : Formula: -2*(V dot N)*N + V Where V is the velocity ...
0
votes
1answer
60 views

How to reposition a bouncing ball after it has passed through a surface

I have a bouncing ball which can collide with lines of a random slope. The ball passes through the lines a bit and I need to set the ball back some distance from the line. The ball (defined by ...
0
votes
1answer
315 views

Custom arcade physics rate (e.g. bullet time)?

Is there a way to modify the rate that physics is applied, either globally or on a per-sprite basis in Phaser? That is, how can I slow down or speed up the rate at which sprites move around, or fall ...
1
vote
3answers
108 views

Unity2D: Apply gravity to some items, when everything else is gravity-free?

Sorry for the incredibly vague title: Let's say you have an NPC, and when he dies he'll spawn items, coins for example. Instead of just pushing the coins in random directions it would look a lot ...
5
votes
1answer
656 views

Programming Dynamic 3D Water/Waves?

I'm a little bit stuck on how I might go about programming dynamic, interesting water in a game. To qualify that a little bit, I'm interested in creating water with broad, rolling waves that affect ...
2
votes
1answer
237 views

How can I manage the deceleration of units so that they arrive on-target?

When I first started trying to set up my air units' movement in my RTS game, I thought it was going to be easy with simple Euler method linear acceleration. This was far from the case as the ship ...
1
vote
3answers
1k views

Unity rigidbody2d.velocity jumping causes weird bouncing

Im working on a game 2d game that has some platforming. I followed this video as guidance and produced the following code: public class PlayerControler : MonoBehaviour public float ...
0
votes
1answer
183 views

Launch Velocity for Simple 3D Projectile [duplicate]

This is a pretty easy question, but I can't quite figure out the answer. I have: The initial position of a projectile. The gravity vector. The (stationary) target I want to hit. A maximum launch ...
7
votes
1answer
296 views

How can I implement large moving “colossus” characters that also act as environmental objects?

I'm curious how enormous characters that act both as entities and environments are implemented. I'm thinking of characters like in Shadow of the Colossus which move, but which the player can also ...
3
votes
3answers
348 views

How to make an object oscillate left and right?

I can't seem to make an object move left and right, back and forth, on room start whilst on solid ground. Codes I used: Step Event: if image_index is greater than 5, then physics_apply_force ...
1
vote
1answer
695 views

Anchoring HingeJoint2D to clicked upon spot

I'm creating a 2D game where the user can click and drag objects around. This is done by connecting a 'Hand' object to the object the user is current clicking on with a HingeJoint2D. Right now it ...
0
votes
2answers
355 views

Trajectory of a spinning ball

How do I would precalculate trajectory of a kicked ball, when it's spinning? I'm applying spinning using simplified Magnus effect every frame like this and it works: acceleration += swerve × ...
9
votes
3answers
204 views

Physics simulation methods for large delta times?

What physics simulation methods are most suitable for really big delta time (hours to weeks)? In addition, would I face any problems combining different methods for big and small delta times?
13
votes
4answers
2k views

How could I constrain player movement to the surface of a 3D object using Unity?

I'm trying to create an effect similar to that of Mario Galaxy or Geometry Wars 3 where as the player walks around the "planet" gravity seems to adjust and they don't fall off the edge of the object ...
2
votes
1answer
342 views

2D bouncing ball simulation - angular velocity

How does angular velocity of a ball affects it's speed after a bounce? I'm trying to simulate 2D bouncing ball physics. I've found a nice solution how to calculate ball's velocity after a bounce: ...