我正在玩CAEmitterCell,但大多数效果都是非常快速的效果,比如烟花。 但我希望像www.findyourwaytooz.com
上看到的那样有一个缓慢的“星星”效果如何使用CAEmitterCell执行此操作?
谢谢:)
答案 0 :(得分:7)
我有一个项目,它使用以下设置的发射器,它非常准确地模仿我的意思:
//set ref to the layer
starsEmitter = (CAEmitterLayer*)self.layer; //2
//configure the emitter layer
starsEmitter.emitterPosition = CGPointMake(160, 240);
starsEmitter.emitterSize = CGSizeMake(self.superview.bounds.size.width,self.superview.bounds.size.height);
NSLog(@"width = %f, height = %f", starsEmitter.emitterSize.width, starsEmitter.emitterSize.height);
starsEmitter.renderMode = kCAEmitterLayerPoints;
starsEmitter.emitterShape = kCAEmitterLayerRectangle;
starsEmitter.emitterMode = kCAEmitterLayerUnordered;
CAEmitterCell* stars = [CAEmitterCell emitterCell];
stars.birthRate = 0;
stars.lifetime = 10;
stars.lifetimeRange = 0.5;
stars.color = [[UIColor colorWithRed:255 green:255 blue:255 alpha:0] CGColor];
stars.contents = (id)[[UIImage imageNamed:@"particle.png"] CGImage];
stars.velocityRange = 500;
stars.emissionRange = 360;
stars.scale = 0.2;
stars.scaleRange = 0.1;
stars.alphaRange = 0.3;
stars.alphaSpeed = 0.5;
[stars setName:@"stars"];
//add the cell to the layer and we're done
starsEmitter.emitterCells = [NSArray arrayWithObject:stars];
我将示例项目上传到GitHub:SimpleCAEmitterLayer