Relating to the motion of objects through space (in 2 dimensions (x,y)) and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.

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5
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2answers
150 views

Determining a sensible gear-like hierarchy for a series of connected objects

I would like a series of objects to behave in similar manner to a series of connected gears. This means that each black object in the diagram below will rotate at a speed based on the ratio of their ...
2
votes
2answers
221 views

Sprite Kit - containsPoint for SKPhysicsBody?

I have a ball bouncing around the screen. I can pick it up and drag it onto a "bucket". When my touches finish, I use the containsPoint function to check and see if I have dropped the ball onto the ...
0
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2answers
514 views

Use both AddForceAtPoint and change velocity property?

I'm using Rigidbody2D for some game objects. It seems that when I AddForce() or AddForceAtPoint(), the game objects are mostly affected on the Y axis and hardly at all on the x axis. I don't ...
2
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1answer
186 views

How to impale and stack targets correctly according to the collider and its coordinate?

I'm making another simple game, a catch game, where a spawning target game object must be captured using a skewer to impale it. Here how: At the start, the falling object (in red) will fall in a ...
1
vote
1answer
577 views

Spritekit - gradually apply force vector in different direction (space ship turning)

I have a space ship that I'm applying a force vector to using a joystick for control. I would like this to smoothly fly around when I'm switching directions.. Exactly like minisquadron if you've ...
0
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1answer
41 views

Moving one object from one point to another with acceleration

How would someone implement moving an object from one point in 2D space to another using these formulae to update objects: m_position.setX/Y( m_position.X/Y() + m_velocity.X/Y() * dt + 0.5 * m_acc * ...
0
votes
1answer
194 views

LibGDX Bounding Rectangles

I'm creating some rectangles surrounding my sprites for my player and bullet class to detect collisions with the overlaps method in Intersector class of LibGDX. I have a question: When I instantiate ...
0
votes
1answer
443 views

Swinging a sword in Xcode with Sprite Kit

I'm working on making an RPG in Xcode, and I'm having a major gameplay issue when it comes to having my character swing his sword in a way that is realistic and gameplay compatible. Right now, when ...
0
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1answer
161 views

Mobile: Physics and movement actions

I've been using spritekit for a while for a few small games. One thing I've noticed is that spritekit is the first game framework I've used that allows me to apply move actions to physics bodies. ...
0
votes
1answer
1k views

Slope polygon collider 2D causing box collider 2D to 'bump' while sliding on it

I'm doing procedural terrain generation. So far I've created the mesh, and attached a 2D polygon collider to it. The terrain is made up of hills going up and down. After doing so, I put a 2D rigid ...
-1
votes
1answer
47 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 ...
-1
votes
1answer
74 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 ...
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votes
1answer
406 views

Trajectory Projectile with Collision Detection

Right now I am trying to create projectile for cannon in which I want to detect collision also. At present I have simple working projectile after using two references Unity – How to display ...
-1
votes
1answer
400 views

How is destructable terrain made in SDL?

I'm looking for terrain that gets removed in chunks (like in Worms, of instance). How do you do this in SDL?
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vote
0answers
61 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 ...
1
vote
0answers
49 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 ...
1
vote
0answers
102 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 ...
1
vote
0answers
630 views

Ease Rotate RigidBody2D toward arbitrary angle

I'm trying to make a rigidbody2D circle return to an orientation after a collision. But there is a weird behavior I do not expect - it always orients to the same direction. This is what I call in ...
1
vote
0answers
83 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
544 views

Cocos2d and Body with few collision shapes using chipmunk

I'm using Cocos2d (0.99.5) with chipmunk physics engine. Currently I'm trying to place a body into space which is combined from few circle shapes. Let's say I have a corresponding sprite image with ...
0
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0answers
48 views

Rain World : How to have intelligent movement / animation?

In the project RainWorld the characters seem to move "intelligently" as they move "unrestricted". They seem to know "how" to move their limbs and "what" needs to be done. Here for an example the ...
0
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0answers
12 views

How can I track a leader vehicle at a specific angle and distance?

I am using Matlab and have code which allows a vehicle to find its way to certain coordinates chosen by the user. I now want to add a second vehicle which stays fixed at a specific distance and angle ...
0
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0answers
67 views

Physics2D.OverlapCircleAll seems to be bigger than my radius

Im trying to make a "Scorched earth"-like game using unity. I managed to fire my bullet and make it explode on contact. What I am trying to do is do some damage to the tanks even if the bullet didn't ...
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0answers
31 views

Does unused 2D colliders in Unity affects performance? Is an Edge Collider more performance friendly than BoxCollider2D?

I am using a lot of gameobjects for my platformer that uses BoxCollider2D component to make the scene floor. But only an a selected set of gameobjects actually have some interaction with the player, ...
0
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0answers
30 views

PhysicsJS object falls through the world

I have a problem while using PhysicsJS when it comes to collisions. I created a physics world, an object and applied gravity. I put the object at a certain position, it falls down because of the ...
0
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0answers
71 views

SpriteKit: Is applyImpulse not working correctly?

I am writing a free throwing system and because of this, I created a ball using following code. self.ball.position = CGPointMake(posX, posY) self.ball.fillColor = SKColor.blueColor() ...
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0answers
21 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 ...
0
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0answers
17 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
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0answers
48 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
94 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
81 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
0answers
55 views

How to determine positions to draw lines on a screen with AndEngine

I have a screen (480x800), M(mx, my) is a static point, and N(nx,ny) is a dynamic point on screen. Position of N(nx, ny) depends position of touch. I want to determine position of P(?,?) and Q(?,?) to ...
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0answers
133 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
75 views

Particle friction with variable timestep in XNA

Alright, so I'm working on an engine of sorts in XNA (yes, it's deprecated, I know) and I'm implementing my own particle system. I've defined a "ParticleEffect" such that when it's supplied a GameTime ...
0
votes
0answers
43 views

Box2d not showing consistent behaviour with sprites

Box2D newbb here. My question is in regards to this create js project:http://mboyeman.com/dashingdog/ (runs best in IE...:3) I wrote a function(assignBlockBodies) to give 2D Edges to sprites based on ...
0
votes
0answers
136 views

Moving objects smoothly, bad perfomance

I just finished developing my mini-game on Android and I got some questions about perfomance and generally "how to": If I have 25+ objects on the creeen (just a polygon with 7-8 angles) its starts to ...
0
votes
0answers
149 views

How to find correct offset to adjust sprite to the position of box2D body after rotation

I am trying to implement phsyics with the as3 box2d port. I currently have a b2body for each of some certain sprites in my game and I am able to update the sprite's positions correctly from the ...
0
votes
0answers
60 views

Apply impulse to ball to a fixed height Jbox2D android

I have to hit a ball to a fixed height repeatedly as shown in the following image. This game is similar to 1983 Hitit The difference is the hitting y axis will be variable. I wanted to hit the ...
0
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0answers
55 views

Lateral Friction Phisics

I am trying to create a physics engine for my game, and need to cancel out any lateral velocity for when entities turn. I have tried to mimic this page's example, but it is not working. I have objects ...