3D perspective view in iphone game using cocos2d

Question

I am developing 'Paper Toss' for iphone using cocos2d & I would like to know that how to implement 3D perspective view into this,because while we are throwing the paper ball to the bin,we have to get the 3D feel.I'am attaching the code which i have done,using this i have got a straight line motion.Please help me..

*- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

// Choose one of the touches to work with
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:[touch view]];
location = [[CCDirector sharedDirector] convertToGL:location];

// Set up initial location of projectile
CGSize winSize = [[CCDirector sharedDirector] winSize];
CCSprite *projectile = [CCSprite spriteWithFile:@"ball.png" 
                                           rect:CGRectMake(0, 0, 40, 40)];
projectile.position = ccp(winSize.width/2,20);

// Determine offset of location to projectile
int offX = location.x - projectile.position.x;
int offY = location.y - projectile.position.y;

// Bail out if we are shooting down or backwards
if (offY <= 0) return;

// Ok to add now - we've double checked position
[self addChild:projectile];

// Determine where we wish to shoot the projectile to
int realY = winSize.height + (projectile.contentSize.width/2);
float ratio = (float) offX / (float) offY;
int realX = (realY * ratio) + projectile.position.x;
CGPoint realDest = ccp(realX, realY);

// Determine the length of how far we're shooting
int offRealX = realX + projectile.position.x;
int offRealY = realY + projectile.position.y;
float length = sqrtf((offRealX*offRealX)+(offRealY*offRealY));
float velocity = 480/1; // 480pixels/1sec
float realMoveDuration = length/velocity;

// Move projectile to actual endpoint
[projectile runAction:[CCSequence actions:
                       [CCMoveTo actionWithDuration:realMoveDuration position:realDest],
                       [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)],
                       nil]];
//add to the projectiles array
projectile.tag = 2;
[_projectiles addObject:projectile];

}*

Answer 1

Finally I have completed paper toss using cocos2d.I implemented bezier curve and here it is,

  // Bezier curve control points
  bezier.controlPoint_1 = ccp(location.x-CONTROL_POINT1_X, CONTROL_POINT1_Y);
  bezier.controlPoint_2 = ccp(location.x-CONTROL_POINT2_X, CONTROL_POINT2_Y);
  bezier.endPosition = ccp(location.x-CONTROL_POINT1_X,distance);

  // Motion along bezier curve and finally call a function
  [projectile runAction:[CCSequence actions:
                           [CCAutoBezier actionWithDuration:DEFAULT_ACTION_DURATION bezier:bezier],
                           [CCCallFuncN actionWithTarget:self selector:@selector(collisionCheck:)], nil]];

Answer 2

Just scale your sprite image so it gets smaller the "further away" it is.