能产生粒子效果的CAEmitterLayer
下雪效果:
//
// RootViewController.m
// Cell
//
// Copyright (c) 2014年 Y.X. All rights reserved.
//
#import "RootViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor blackColor];
// 创建粒子Layer
CAEmitterLayer *snowEmitter = [CAEmitterLayer layer];
// 粒子发射位置
snowEmitter.emitterPosition = CGPointMake(120,20);
// 发射源的尺寸大小
snowEmitter.emitterSize = self.view.bounds.size;
// 发射模式
snowEmitter.emitterMode = kCAEmitterLayerSurface;
// 发射源的形状
snowEmitter.emitterShape = kCAEmitterLayerLine;
// 创建雪花类型的粒子
CAEmitterCell *snowflake = [CAEmitterCell emitterCell];
// 粒子的名字
snowflake.name = @"snow";
// 粒子参数的速度乘数因子
snowflake.birthRate = 1.0;
snowflake.lifetime = 120.0;
// 粒子速度
snowflake.velocity =10.0;
// 粒子的速度范围
snowflake.velocityRange = 10;
// 粒子y方向的加速度分量
snowflake.yAcceleration = 2;
// 周围发射角度
snowflake.emissionRange = 0.5 * M_PI;
// 子旋转角度范围
snowflake.spinRange = 0.25 * M_PI;
snowflake.contents = (id)[[UIImage imageNamed:@"snow"] CGImage];
// 设置雪花形状的粒子的颜色
snowflake.color = [[UIColor whiteColor] CGColor];
snowflake.scaleRange = 0.6f;
snowflake.scale = 0.7f;
snowEmitter.shadowOpacity = 1.0;
snowEmitter.shadowRadius = 0.0;
snowEmitter.shadowOffset = CGSizeMake(0.0, 0.0);
// 粒子边缘的颜色
snowEmitter.shadowColor = [[UIColor whiteColor] CGColor];
// 添加粒子
snowEmitter.emitterCells = @[snowflake];
// 将粒子Layer添加进图层中
[self.view.layer addSublayer:snowEmitter];
}
@end烟花效果:
//
// RootViewController.m
// Cell
//
// Copyright (c) 2014年 Y.X. All rights reserved.
//
#import "RootViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor blackColor];
// Cells spawn in the bottom, moving up
CAEmitterLayer *fireworksEmitter = [CAEmitterLayer layer];
CGRect viewBounds = self.view.layer.bounds;
fireworksEmitter.emitterPosition = \
CGPointMake(viewBounds.size.width/2.0, viewBounds.size.height);
fireworksEmitter.emitterSize = CGSizeMake(viewBounds.size.width/2.0, 0.0);
fireworksEmitter.emitterMode = kCAEmitterLayerOutline;
fireworksEmitter.emitterShape = kCAEmitterLayerLine;
fireworksEmitter.renderMode = kCAEmitterLayerAdditive;
fireworksEmitter.seed = (arc4random()%100)+1;
// Create the rocket
CAEmitterCell* rocket = [CAEmitterCell emitterCell];
rocket.birthRate = 1.0;
rocket.emissionRange = 0.25 * M_PI; // some variation in angle
rocket.velocity = 380;
rocket.velocityRange = 100;
rocket.yAcceleration = 75;
rocket.lifetime = 1.02; // we cannot set the birthrate < 1.0 for the burst
rocket.contents = (id) [[UIImage imageNamed:@"DazRing"] CGImage];
rocket.scale = 0.2;
rocket.color = [[UIColor redColor] CGColor];
rocket.greenRange = 1.0; // different colors
rocket.redRange = 1.0;
rocket.blueRange = 1.0;
rocket.spinRange = M_PI; // slow spin
// the burst object cannot be seen, but will spawn the sparks
// we change the color here, since the sparks inherit its value
CAEmitterCell* burst = [CAEmitterCell emitterCell];
burst.birthRate = 1.0; // at the end of travel
burst.velocity = 0;
burst.scale = 2.5;
burst.redSpeed =-1.5; // shifting
burst.blueSpeed =+1.5; // shifting
burst.greenSpeed =+1.0; // shifting
burst.lifetime = 0.35;
// and finally, the sparks
CAEmitterCell* spark = [CAEmitterCell emitterCell];
spark.birthRate = 400;
spark.velocity = 125;
spark.emissionRange = 2* M_PI; // 360 deg
spark.yAcceleration = 75; // gravity
spark.lifetime = 3;
spark.contents = (id) [[UIImage imageNamed:@"snow"] CGImage];
spark.scaleSpeed =-0.2;
spark.greenSpeed =-0.1;
spark.redSpeed = 0.4;
spark.blueSpeed =-0.1;
spark.alphaSpeed =-0.25;
spark.spin = 2* M_PI;
spark.spinRange = 2* M_PI;
// putting it together
fireworksEmitter.emitterCells = [NSArray arrayWithObject:rocket];
rocket.emitterCells = [NSArray arrayWithObject:burst];
burst.emitterCells = [NSArray arrayWithObject:spark];
[self.view.layer addSublayer:fireworksEmitter];
}
@end/* The birth rate of each cell is multiplied by this number to give the
* actual number of particles created every second. Default value is one.
* Animatable. */
@property float birthRate;
/* The cell lifetime range is multiplied by this value when particles are
* created. Defaults to one. Animatable. */
@property float lifetime;
/* The center of the emission shape. Defaults to (0, 0, 0). Animatable. */
@property CGPoint emitterPosition;
@property CGFloat emitterZPosition;
/* The size of the emission shape. Defaults to (0, 0, 0). Animatable.
* Depending on the `emitterShape' property some of the values may be
* ignored. */
@property CGSize emitterSize;
@property CGFloat emitterDepth;
/* Multiplies the cell-defined particle velocity. Defaults to one.
* Animatable. */
@property float velocity;
/* Multiplies the cell-defined particle scale. Defaults to one. Animatable. */
@property float scale;
/* Multiplies the cell-defined particle spin. Defaults to one. Animatable. */
@property float spin;
你需要知道的非常重要的细节:
CAEmitterCell的动画属性挺多的,但有点奇葩的是,必须是通过KVC设置值才行的通,而且,动画结束时的值也必须通过KVC设置才有效......
//
// RootViewController.m
// Cell
//
// Copyright (c) 2014年 Y.X. All rights reserved.
//
#import "RootViewController.h"
#import "YXGCD.h"
@interface RootViewController ()
@end
@implementation RootViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor blackColor];
// 创建粒子Layer
CAEmitterLayer *snowEmitter = [CAEmitterLayer layer];
// 粒子发射位置
snowEmitter.emitterPosition = CGPointMake(120,20);
// 发射源的尺寸大小
snowEmitter.emitterSize = self.view.bounds.size;
// 发射模式
snowEmitter.emitterMode = kCAEmitterLayerSurface;
// 发射源的形状
snowEmitter.emitterShape = kCAEmitterLayerLine;
// 创建雪花类型的粒子
CAEmitterCell *snowflake = [CAEmitterCell emitterCell];
// 粒子参数的速度乘数因子
snowflake.birthRate = 20.0;
snowflake.lifetime = 120.0;
// 粒子速度
snowflake.velocity =10.0;
// 粒子的速度范围
snowflake.velocityRange = 10;
// 粒子y方向的加速度分量
snowflake.yAcceleration = 200;
// 周围发射角度
snowflake.emissionRange = 0.5 * M_PI;
// 子旋转角度范围
snowflake.spinRange = 0.25 * M_PI;
snowflake.contents = (id)[[UIImage imageNamed:@"snow"] CGImage];
// 设置雪花形状的粒子的颜色
snowflake.color = [[UIColor whiteColor] CGColor];
snowEmitter.shadowOpacity = 1.0;
snowEmitter.shadowRadius = 0.0;
snowEmitter.shadowOffset = CGSizeMake(0.0, 0.0);
// 粒子边缘的颜色
snowEmitter.shadowColor = [[UIColor whiteColor] CGColor];
// 粒子的名字
snowflake.name = @"snow";
// 添加粒子
snowEmitter.emitterCells = @[snowflake];
// 将粒子Layer添加进图层中
[self.view.layer addSublayer:snowEmitter];
// 7秒后执行
[[GCDQueue mainQueue] execute:^{
// 设置基本动画
CABasicAnimation *ani = \
[CABasicAnimation animationWithKeyPath:@"emitterCells.snow.birthRate"];
ani.fromValue = @(20.0);
ani.toValue = @(0.0);
ani.duration = 12.f;
// 设置结束时的值
[snowEmitter setValue:[NSNumber numberWithFloat:0]
forKeyPath:@"emitterCells.snow.birthRate"];
// 添加动画
[snowEmitter addAnimation:ani forKey:nil];
} afterDelay:NSEC_PER_SEC * 7];
}
@end