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

learn more… | top users | synonyms

2
votes
0answers
47 views

Physics: calculating angular acceleration in world vs local space

I have a pretty simple rigid body simulation written in Python. In my code I calculate the angular acceleration using formula: angAcc = torque * inertiaTensor^-1 (note row-major matrix order) Now, ...
2
votes
0answers
216 views

How do I compute the angle between a pixel on an irregular curve and a circle colliding with it?

I'm building a custom physics engine to accompany a level-editor. This image shows how the level-editor outputs levels: Now, some explanation is in order. The curve is defined by the red points. ...
2
votes
0answers
306 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: impulse = desired_velocity_change * mass impulse = force * time friction_force <= ...
2
votes
0answers
90 views

What is the most effective way to create a set of collision points for an aribitrary mesh?

In my project I am working on automatically deforming an arbitrary mesh with respect to another arbitrary mesh, within the context of user generated content, similar to this deformer being developed ...
1
vote
0answers
47 views

Calculate Orbit Path/Ellipse given mass, velocity, and distance (2body)

Calculate and draw the path of an orbit in a 2 body problem given the mass, current velocity, and distance of both bodies? We're working in Unity and will be using the default rigidbody.mass to start ...
1
vote
0answers
61 views

Create a 2D orbit trajectory like in angry birds space and a circular orbit

I am working on a 2D game, and I am working on adding some space physics : I need to find a way to create a circular orbit and an orbit like angry birds space ( the spiral trajectory ) . So there is 2 ...
1
vote
0answers
80 views

How do I implement realistic recovery from weapon recoil?

I want to create an equation determining how fast a gun recovers back to its center after it has fired. I have a weapon system functioning based on constants (recoil amount, bullet spread, etc.) ...
1
vote
0answers
437 views

Getting child collider when collision occurs in compound object in unity3d?

I have a compound object. The parent of the compound object hierarchy has a script that is listening to the OnTrigerXXX callbacks of the children. When this compound object collides with other objects ...
1
vote
0answers
53 views

Manual response when 2 shapes made of rectangular volumes collide

I have 2 compound objects made of rectangular blocks. One of them (the one that is moving) has a script that listens to OnTrigger callbacks. What I need is to position the moving compound object on ...
1
vote
0answers
146 views

How do I detect collisions between a particle-based net and a ball?

I've implemented a net using Verlet integration and many points connected with constrains; like this demo, but in 3D. I want to implement collision detection between this net and a ball (like in a ...
1
vote
0answers
58 views

How to apply physics when you have sub frame state changes?

I'm currently calculating my physics every 1/100th of a second and using a state machine to manage the current state of the player. In my main loop I'm checking user input and transitioning the state ...
1
vote
0answers
76 views

PhysX - Revolute joint around unit vector

I'm using a right-handed coordinate system with (0,0,-1) = forward, (1,0,0) = right and (0,1,0) = up. PhysX version is 3.3.0. I have a unit vector which represents the axis around which my actor is ...
1
vote
0answers
50 views

Bullet Physics ConvexDecomposition?

I've looked at Bullet Physics ConvexComposition Demo and would like to implement that in my game but the code is so undescriptive and it's hard to understand what is going on. Would any of you people ...
1
vote
0answers
186 views

How do I combine multiple squares into one Tetris block?

I am learning Phaser by making a simple game—Tetris. I'm having difficulties: Can I use simple rectangles as tetrominoes or they should be sprites? I don't know how make the figure's block ...
1
vote
0answers
105 views

How do you calculate the rate of rotation using the accelerometer values in Android for a particular axis?

I am developing a simple game which involves a character moving up and down only along the Y axis. Currently I am using the accelerometer readings to change the Y velocity of the character. The game ...
1
vote
0answers
115 views

How to aim with a spaceship in 3D considering its angular momentum?

So I have a spaceship and I have 6 degrees of freedom. At a given moment the following vectors are known of the spaceship: Local forward. Local up. Local sideways (may be implied from the previous ...
1
vote
0answers
1k views

Why do restitution values less than one still cause infinite bouncing in Box2D?

I'm currently trying to implement basketball bouncing into my game using Box2d (jBox2d technically), but I'm a bit confused about restitution. While trying to create the ball in the testbed first, ...
1
vote
0answers
188 views

How do I implement a physics gun?

I'm currently trying to implement a physics gun for my game. What I want is for the entity to stay in the same position on the screen no matter how I wiggle the camera about, what is the correct way ...
1
vote
0answers
1k views

Unity3D: collider performances on mobile iOS devices

I'm experimenting with Unity3D and colliders. Unfortunately I still don't have Unity Pro version and I can't use the profiler. Consider the following situation: mobile devices (ios, iphone 3GS). an ...
1
vote
0answers
142 views

Collision shape and Model problem

I used BEPUphysics for my XNA 4.0 game , the problem is that I load my model.fbx from into the game then add it to the space of physics engine , but when I change the scaling matrix of my Model then ...
1
vote
0answers
759 views

Unity3d Gravity script issues

I'm try this script out http://wiki.unity3d.com/index.php/Gravity and I'm having some issues with it (it seemed to work when I tried it with an old version of unity) the first issue is of ...
1
vote
0answers
210 views

Updating physics for animated models

For a new game we have do set up a scene with a minimum of 30 bone animated models.(shooter) The problem is that the update process for the animated models takes too long. Thats what I do: Each ...
1
vote
0answers
304 views

Need help with objects moving toward the player

I am making a 2D game with simple "gravity": everything is just pulled toward 0,0. The speed at which they accelerate towards it is GravityAcceleration up to MaxGSpeed. I also want the player to be ...
1
vote
0answers
400 views

How do I properly use multithreading with Nvidia PhysX?

I'm having a multithreading problem with Nvidia PhysX. the SDK requires that you call Simulate() (starts computing new physics positions within a new thread) and FetchResults() (waits 'till the ...
1
vote
0answers
509 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
25 views

Implementing realistic 3d character movement

I'm trying to create realistic feeling character movement, but I would like to use realistic physics as well. I've been trying to find some online sources but can't find a lot of information about ...
0
votes
0answers
25 views

How to calculate multiple collision of sphere and triangles?

I have a sphere and a mesh(triangles). When the sphere intersects the triangle, I reflects the vector of speed and everything works fine. But I can't write a good implementation for multiple ...
0
votes
0answers
42 views

Implementing wall-sliding physics in THREE.js

Yo, Basically I want to make a 3D environment where the player can walk around a 3D world, and collides with objects / terrain like any other 3rd person / 1st person game. The world can contain any ...
0
votes
0answers
43 views

How to slow down a Sphere smoothly in a world controlled by force and stop it (Unity 5)?

I am a beginner and I started to use Unity 5. I play with tutorials on the site and documentation. I was basically testing springs, physics materials etc. I have a problem understanding probably a ...
0
votes
0answers
25 views

JBullet Only Updates Position when I update it in Code

The title is a bit weird...but here it goes: I have JBullet configured so that I can move things in my code, as the game tick structure is something like this (the update code located in ...
0
votes
0answers
41 views

(LibGDX/JAVA) How can I get a rectangle to rotate with this pendulum so I can start detecting collisions?

One of the objects in my game is a pendulum that swings in a semi-circle. This is done by having an update() method like this: public void update() { angleAcceleration = +1.81 / length * ...
0
votes
0answers
35 views

Leapfrog integration vs Euler integrator

I am looking at various integration methods for my n-body simulation and I'm slightly confused about actual implementation of leapfrog integration. According to the wikipedia page leapfrog method is ...
0
votes
0answers
104 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 ...
0
votes
0answers
55 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
0answers
65 views

moving a character in sprite kit

So I've created a game in which a number of tiles are created from a txt file to create a level for the player to navigate through, but I'm having trouble moving the player. func ...
0
votes
0answers
42 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 ...
0
votes
0answers
40 views

How to get rid of “ghost mode”?

I've got few Spatials (mostly boxes) in my space. Player is able to move main Spatial using mouse or keybord. But now every Spatial can go through another. Like in a ghost mode. How can I get rid of ...
0
votes
0answers
57 views

Calculate hit-normal from collision

I am trying to implement a swept test collision between an AABB and a Line Segment and I found this implementation working great ... Except that it doesn't cover how to calculate the hitNormal and ...
0
votes
0answers
23 views

Impulse resolution with varying time delta

I thought I'd try building a basic 2D physics engine, and I'm currently writing the impulse resolution part of it (yeah, not very far into this). Using quick internet tutorials like this as a guide, ...
0
votes
0answers
50 views

Calculation technique for 2D inertia tensors?

Just wondering what the techniques are out there. It's only 2D so I figured there'd be a good chance for there to be a "one size fits all" solution out there that's essentially an analytical solution. ...
0
votes
0answers
35 views

How do I apply Farseer Physics Engine Collision on my image? I tried it on my codes and it is not working

How do I apply Farseer Physics Engine Collision on my image? I tried it on my codes and it is not working. PoolGameSingle poolgame = new PoolGameSingle(); var cue = poolgame.CueStick; ...
0
votes
0answers
156 views

How to determine velocity from force

I recently started a project with the intention to master the physics aspect of Unity. Although I have a good knowledge of Unity, I never had the opportunity to work on game that makes extensive use ...
0
votes
0answers
33 views

Applying angular velocity distorts model

I am calculating the orientation of a sphere through the following code wV = new Vector3(0, pi/2, 0); w = new Quaternion(wV, 0); // o is the current Orientation o.Normalize(); w = 0.5f * w * o; // dt ...
0
votes
0answers
69 views

How to get yaw of bullet physics vehicle?

I am using the Bullet Physics port to java, JBullet, and am trying to render a vehicle body that i created in Blender on top of the vehicle chassis. Since i cannot effectively find a way to render ...
0
votes
0answers
197 views

How to move rigidbody player to its facing direction with AddForce?

How can I move a rigidbody to its facing direction? I've already tried this: rigidbody.AddForce (transform.forward * v, ForceMode.Acceleration); // v is a public float which gets a new value in ...
0
votes
0answers
96 views

Implementing a group formation behavior

I am trying to implement a group formation behavior where all the units in my group follow a leader and maintain their position throughout. So far I am able to move them, rotate and follow the leader. ...
0
votes
0answers
84 views

Drawing a object with Box2D and HTML5 canvas on current mouse position

I'm attempting to create a air hockey type game with HTML5 canvas and JavaScript, using Box2dWeb for the physics calculation. I need a way to draw the puck at the current mouse x and y position every ...
0
votes
0answers
59 views

CCTextField won't appear

I can't seem to add a CCTextField in my physics node, I tried all different methods, but it's still not happening. Here's my code: CCTextField *tf = [[CCTextField alloc] init]; tf.contentSize = ...
0
votes
0answers
151 views

Box2D collision damage calculation from postSolve or not?

I'm using postSolve to get impulse then calculate damage base on that impulse. But there's some issue: Stability The damage isn't stable. When the same ball is hitting with same speed, the damage ...
0
votes
0answers
213 views

Realistic collisions with a kinematic rigidbody?

I have a car game where player drives a car; this car has a collider and a kinematic rigidbody attached and is completely controller by script (i.e. a script sets its position and rotation). In the ...