I'm trying to move a sprite in a set direction on-screen, using the physicsBody.velocity
property. However, the motion is quite "jumpy" (makes the game look like it's lagging). I assume this has something to do with the different time intervals between each call to the update
-method. How could I achieve a more "smooth" motion?
Right now this is the code I have in my update-loop to make the sprite move forward:
if (_movingForward) {
CGFloat forwardVel = _ball.physicsBody.velocity.dx;
forwardVel += 20.0;
if (forwardVel > bMaxForwardVelocity) {
forwardVel = bMaxForwardVelocity;
}
_ball.physicsBody.velocity = CGVectorMake(forwardVel, _ball.physicsBody.velocity.dy);
}
As you can see, I'm trying to make the speed pick up, so it doesn't immediately reach it's terminal velocity. This is to make the motion look more natural. However, the lagging is ruining this effect greatly, even when the sprite supposedly is traveling at a set speed.
EDIT 1:
I'm trying to make a platform-style game (like Super Mario etc) where the _ball
moves horizontally along the ground when the user taps the screen. The code for moving the ball to the right is included above the edit. The ground is made up of multiple tiles, each 32x32
and positioned right next to each other with no gap in-between.
As per request, here's the code for setting up the _ball
s physicsBody:
self.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:self.size.width/2.0];
self.physicsBody.dynamic = YES;
self.physicsBody.restitution = 0.5f;
self.physicsBody.usesPreciseCollisionDetection = YES;
self.physicsBody.allowsRotation = NO;
self.physicsBody.mass = 0.5f;
self.physicsBody.friction = 0.0f;
self.physicsBody.linearDamping = 0.0f;
self.physicsBody.categoryBitMask = CollisionCategoryBall;
And here's the code for the physicsBody of each individual tile:
tile.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:tile.size];
tile.physicsBody.dynamic = NO;
tile.physicsBody.categoryBitMask = CollisionCategoryGround;
The physicsWorld is set up like this:
self.physicsWorld.gravity = CGVectorMake(0, -4);
self.physicsWorld.contactDelegate = self;
Thanks!
EDIT 2:
This is a side-scrolling game, so the "camera" follows the ball. Here's the code for moving the background layer:
- (void)centerViewOn:(CGPoint)centerOn {
CGFloat x = Clamp(centerOn.x, (self.size.width / 2.0), (_bgLayer.layerSize.width) - (self.size.width / 2.0));
_worldNode.position = CGPointMake((int)-x, _worldNode.position.y);
}
The reason for the Clamp
is so the "camera" doesn't scroll beyond the bounds of the background. This is when the ball is close to either the start or end of the level.
I'm casting the position to an int
because without it, small gaps sometimes occur between the tiles. I was told this was because of some inaccuracy or something. However, even without casting the position to int, it's still a bitt "laggy". But because of the gaps between the tiles, it looks even worse.