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

8
votes
5answers
5k views

How do I detect the direction of 2D rectangular object collisions?

After this question, I need some more help. How can I find out which side of a rectangle a collision came from and react accordingly? The blue arrows are the paths that some circular objects ...
3
votes
3answers
1k views

Unity 4 - Some Rigidbodies Won't Fall Asleep

I'm having this problem in the free edition of Unity 4.1 where rigidbodies aren't falling asleep (and yes, I've tried playing with the sleepVelocity and sleepAngularVelocity values!). I've read the ...
1
vote
3answers
577 views

How do you properly implement level boundaries in a physics room?

I have an issue with creating a proper boundary in GameMaker Studio when using a physics enabled room. My room has a gravity of 0, as it is in Space. My player object has the default values, but a ...
12
votes
4answers
883 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
0answers
225 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. ...
0
votes
0answers
30 views

How to tell if the ball is on the floor (in nape)?

What I wish to do in pseudo code: points = Get the set of all points (x, y) where the ball is touching other surfaces. point = Get the point out of that set with the minimal (y) value. Check if that ...
2
votes
1answer
361 views

How do I make my camera follow a Box2D object?

I'm implementing a camera in my game. It worked for regular objects, but I began using Box2D and obviously things changed a bit. I have a Body object that I want to draw at the center of the screen. ...
0
votes
2answers
164 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 × ...
1
vote
1answer
123 views

How can I have a Mecanim animation with displacement and physics?

I have 3D wolf models from my animator with displacement (i.e the wolf transforms with animation, not in-place). I have added rigid bodies to the models. I am facing following issues while executing ...
11
votes
4answers
922 views

Animated examples of different interpolations formulas: any link? [closed]

I remember having spotted a link to a huge page with different equations to non linear interpolation curves, for example if you want to stop a car smoothly, etc. Those can sometime be useful to ...
8
votes
3answers
171 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?
1
vote
1answer
88 views

Simplified aerodynamics for 2d (top-down) airplane

I am writing a top-down 2d game, in which the player can control an airplane via the WASD keys. The W key should move the plane upwards (north), the A key to the west, and so on. Now I need a ...
0
votes
1answer
130 views

Creating a Player object in a physics engine [duplicate]

I have a working physics environment using Farseer - but how do I create a player object that can walk around? My current attempt involves applying forces to a rectangular body whenever keys are ...
-2
votes
1answer
94 views

Throwing a bomb LibGDX Box2D [closed]

I am trying to create game where somenone throw a bomb. I am wondering how I can have an bomb react in a way that is represented by the following picture : Is there are any tools in Box2D that can ...
0
votes
1answer
291 views

Jump Issue(Unity3D)

This is my first character control script. Where a cube is my player and the objective the i want to achieve with my script are 1.the cube moves in horizontal axis till the button is pressed once ...
1
vote
0answers
119 views

How to render multiple objects as a single object for fluid simulation?

I'm trying to do fluid simulation using particles in 2d game. I have larger particles, which interactive each other physically, those particles collide with environment (e.g wall,obstacles) to ...
3
votes
1answer
360 views

Change unity physics engine speed

Is there a simple way to change the speed* of unity's physics engine like in the game SuperHot? Any script language is ok but javascript is preferred. *I am not sure if speed is the correct term.
2
votes
1answer
132 views

Implementing character movement using real physics

This is the first time I'm seriously developing a game so apologies if I'm missing the obvious. In my 2D platformer I adopted Box2D since it seemed like a natural solution to model gravitational ...
1
vote
2answers
132 views

How can I handle position in an entity system where position can be 2D or 3D?

I'm working on a game engine to learn how it's done (so I might better take advantage of the techniques involved and other, similar engines in the future), and I've run into a problem when handling ...
1
vote
1answer
53 views

Reduce bounciness of dynamic bodies in Box2D

In my 2D platformer game my player character is modeled using a Box2D dynamic body. One thing I thought feels off though is that even though the restitution of the fixture applied is zero, the player ...
2
votes
0answers
527 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 ...
0
votes
2answers
59 views

Irregular gravity bouncing

I am working in a simple bouncing ball game. The ball moves right to left at a constant speed and back when it collides with the border of the display. But it jumps every time the the user clicks and ...
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 ...
0
votes
0answers
19 views

Box2d - body size or spatial distribution matters for better simulation?

Box2D better works for limited sizes: Box2D works with floating point numbers and tolerances have to be used to make Box2D perform well. These tolerances have been tuned to work well with ...
0
votes
1answer
393 views

Trouble with a modified parallax scrolling concept

I have a set of layers (each of them being a list of items) moving with different speeds as I mentioned here: http://stackoverflow.com/a/18962019/270197. Layers back in the scene move with slower ...
0
votes
0answers
57 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. ...
1
vote
0answers
152 views

Should I use Box2D for collision-detection only (not simulating physics)? [closed]

I'm using Box2D only to check collisions and for no physical simulation. I create bodies (and shapes for them) and use my own code to move them, by setting their velocities and positions every frame. ...
1
vote
2answers
174 views

Framerate dependent movement

I'm moving my character controller using Euler integration like this: Vector3 originalPos = transform.position; Vector3 acceleration = Physics.gravity; velocity += acceleration * Time.deltaTime; ...
0
votes
0answers
122 views

2D Distance Field as collision handler method

Pixeljunk Shooter has really cool fluid simulation. I found the dev's video explaining what they did. Here I understand that it is particle based simulation Smoothed Particle Hydrodynamic I can ...
0
votes
0answers
40 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
2answers
72 views

How do i calculate the velocity of a sprite after it leaves circular motion?

I'm trying to make a game where the character can swing on a rope. I want to know how the velocity of player is calculated when it stops circular motion. Any help would be appreciated.
0
votes
3answers
156 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 ...
0
votes
0answers
198 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
76 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
91 views

Breakout Clone: Ball isn't bouncing as expected

So I'm working on a Breakout Clone using Unity 2D Physics only, and I'm having some trouble with the bouncing effect. Every object in my Scene has a Bounciness of 1. First, this is the code of my ...
0
votes
3answers
72 views

In a Sonic-esque platformer, how to tell if the chracter is upside-down or not?

In a Sonic-esque platform game, how do you know if the player's character is currently upside down? Let's say the character is running to the left: At a certain point the character will begin to ...
2
votes
1answer
111 views

My pool balls often jump around when there are two or more balls colliding/touching

I'm working through the book 'Introduction to Game Physics with Box2D' and I've created a little pool game with the example code. Despite the name, there is NO box 2D used in this particular exercise. ...
9
votes
4answers
20k views

2D character controller in unity (trying to get old-school platformers back)

This days I'm trying to create a 2D character controller with unity (using phisics). I'm fairly new to physic engines and it is really hard to get the control feel I'm looking for. I would be really ...
3
votes
2answers
297 views

Why is Euler integration sometimes preferred over RK4 even if RK4 is more accurate? [closed]

Some high quality engines such as Box2d uses the Simplistic Euler integrator instead for RK4 when Eumplectic Euler commits a global error of the order of Δt whereas, RK4 has Δtˆ4 error? RK4 is not ...
0
votes
1answer
783 views

Box2D recommended step, velocity and position iterations

Here in this article there is a nice explanation that velocity iterations and position iterations settings affect the way bodies will react when they collide, and step affects on speed and how gravity ...
0
votes
1answer
250 views

How to make an object that has no rigidbody2d component smoothly fall on the ground in Unty2d?

I have two character in my game: enemy and main character. Enemy can throw different objects into the main character. For this moment i am doing this action in such way: void FixedUpdate(){ if ...
0
votes
1answer
194 views

Bullet - objects falling through

I have problem with bullet collisions. You can see problem on this video (around 0:18): http://goo.gl/DiVP8l Objects are "embeded" inside vertical bars - that is not correct - they should be ...
1
vote
2answers
101 views

Adding gravity to arrival steering behavior

I trying to write an autopilot for the classic Lunar Lander or its clones. According to this paper, the arrival behavior is exactly what I need for a soft landing. In this example, it accelerates at ...
1
vote
1answer
2k views

Moving rigidbody2d towards mouse click using AddForce

I cant get my rigidbody2d game object to move to where i click the mouse. The first click works. The object travels to the mouse click and stops. But the second time (or the third time) i click the ...
1
vote
0answers
148 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 ...
0
votes
3answers
182 views

Unrealistic sphere behavior on inclined plane

I am trying to model a ball rolling down an inclined surface in Unity based on what I am observing in real life but it is still quite off. In Unity it takes the ball about 3 seconds to travel from a ...
2
votes
1answer
270 views

How do I convert a partially transparent image into polygons?

I'm using GLEE2D, a level editor allowing me to import images, scale them, rotate them, and position them onto layers and export the data into XML format. However, it does not tell me objects' ...
0
votes
1answer
68 views

Fixed joints in 3D

I'd like to build something like rigid origami in 3D space. So I need some mesh where each vertex is a particle and the set of the edges makes a chains/fabric where each edge is a "fixed length" ...
0
votes
0answers
215 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 ...