Breakout Paddle Collision Angle - xna

I'm making a Breakout clone and having a little trouble with the ball-to-paddle collisions. I have a rectangle represent both the ball and the paddle and when they intersect, the Y vector representing the ball's velocity is negated (as shown below). That all works fine. The problem is when the paddle is moving to the right I want it to nudge the ball a little to the right (as opposed to it just reflecting off normally) and I want the same to happen in the opposite direction is the paddle is moving to the left. I'm not sure how to go about doing this and I've looked all over. Any help would be appreciated. Thanks.
if (paddleRectangle.Intersects(ballRectangle))
{
ballVelocity.Y *= -1;
collision.Play(); //a collision sound
}
EDIT: Basically I want to slightly change the angle at which the ball bounces off the paddle based on which direction the paddle is moving. If the paddle is not moving, then the ball will bounce normally (by inverting the Y component of the ball's velocity)

Add the paddle's velocity vector to the paddle's normal vector (this basically bends the normal in the direction the paddle is moving) and normalize the result. Use this as the collision normal for reflection.
Vector2 collisionNormal = Vector2.Normalize(paddleNormal + (paddleVelocity * desiredEffectAmount));
ballVelocity = Vector2.Reflect(ballVelocity, collisionNormal);

i did some grinding in my head... and here are results. to achieve that you will need, moving direction of paddle, speed of paddle, ball speed, ball direction. and then by some math function calucalte angle and speed of bounce.
i think this image (if bouncing is phisicaly correct) will give you idea how to create this. can't help you with function that will handle this but i would go and try that way as in image.

You want a little friction, but probably not real friction.
Try scaling the paddle speed down by some factor and adding it to the ball velocity.

Related

Move along uneven physics body with Sprite Kit

I have a physics body that is uneven but not dynamic (the terrain) and a physics body (character) that is dynamic and is on top of the terrain, and I want this character to move along the terrain simulating kind of a "walking" action where it will keep going up the terrain but it won't fall back (or move back) like a ball because of gravity, and to set a maximum tilt so that it does not tip over.
My attempt was to add a force in the direction I want the character to move but this is causing the character to fall back due to gravity, and I don't want to disable gravity because then character won't fall down when going down the terrain.
Thank you very much
this is why using a physics engine for a platforming game is very difficult and not always a great approach..
you can try sprite.physicsBody.allowsRotation = false
might help
Create SKAction to move your character to destination point or dx and dy. Run that SKAction from your character node with the runAction. Like
SKAction.moveByX(...
When the action is finished, gravity will bring the character down.
If the movement is slow, play with the character's physicsBody friction and/or mass.
You can also change the the character's physicsBody.velocity = CGVectorMake(
And your terrain will be better with edgeLoop physicsBody which won't be dynamic.
And with uneven you mean inclined but smooth? If not smooth and with edges, your character may get held up at an edge depending on center of gravity of character and if you are allowing rotation.

Change direction of moving SKSpriteNode?

I have a moving ball which is SKSpriteNode, and I want to change its direction alone without applying any force or impulse . When user starts touch interactions, I want the moving ball to move in the direction of touch.
In the picture the ball is initially given a impulse. I don't want to change the velocity of ball but what I want is I just want to move it to right or left from its current position based on user touch. When user tap on right side of ball, the ball should bend little bit toward right and vice - versa.
Things I Tried
Applied impulse over ball in the touch direction and it caused ball to move extremely fast after few touches.
Applied SKAction movetoPoint method and gave my touch point to that method but it resulted in direction flip (i.e.) when ball is moving from bottom to top and if touch point is below the ball, It resulted in inverting ball direction. I Just want ball to bend along touch point without inverting its direction.
Any help or suggestions would be greatly appreciated.
Made to to work by making velocity to 0 when user touches began and then by applying an impulse in the direction of touch. Anyways thank you bro for your help.

Sprite-Kit: Applying physics to a projectile under the influence of moveTo

I am making a top down game where I am having cannons fire and having their projectiles move to the clicked location via the SKAction moveTo:duration. I am supposed to have wind change the trajectory so I have the cannonball implemented as an SKPhysicsBody and I am setting gravity to be a the windspeed since it is the only thing I can find that applies a constant force like wind would. The problem I am having is moveTo is probably the wrong way to be implementing the cannonball. The ball moves according to the path it should but then lands at the tapped location which is not what I want. I can't find a good alternative to moveTo. Any ideas?
You have to solve the projectile equations to determine the force needed and angle to applyImpulse. Solving the equation is only considering the gravity force and impulse force applied to projectile using the applyImpulse with your distances known from your cannons to user's click projectile destination.
Your applyImpulse launches the projectile, you start your wind and other external forces which will have an impact on the projectile path, changing it's destination from that of user's clicked.
You need to know few physics and math to re-arrange the equations and solve them :)
Not sure if you need to do all the advanced math, just set the angle of your cannon and apply impulse to the cannonball, and use the scene.physicsWorld.gravity as your wind, just make sure you also give your cannonball a physicsbody that has dynamic and affectedByGravity set to true.
To calculate the angle, you would do:
let angle = atan2(Double(touch.y - cannon.y),Double(touch.x - cannon.x))

Setting Spritekit gravity source

Is there any way to set an x,y coordinate that gravity pulls towards?
We want to suck a number of objects with physicsbodies towards a point as if it was a black hole.
Not for the regular world gravity.
To achieve this effect, you have to apply to each body an impulse every frame. The strength and direction of the impulse depends on the distance of the body (node) to the gravity source's position.

2D vector math with direction and velocity

Heyo!
I'm starting to create games on iOS and I'm trying a Breakout-clone for start. As practice I wanted a ball to bounce around in a rectangle so I get my head around simple collision, direction and velocity.
My ball got the following:
Point position; // x, y
float direction;
float velocity;
In my "update" function, I want to move the ball in the current direction. What is the next position considering the velocity and direction?
Are there any helpers in some built-in frameworks in iOS?
I would really like to learn more about 2D-math so if someone got some reasources I would really appreciate if you send me a link.
What is the next position considering the velocity and direction?
Note that velocity already has direction; it is a vector
Bearing that in mind, your new position is:
position = CGPointMake(position.x + velocity.x, position.y + velocity.y)
Make velocity a CGPoint and make your direction variable redundant.
Convert the direction and velocity into a vector, scale it for time, and then add it to the current position, accounting for obstacles encountered along the path.

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