跨平台游戏编程与 gameplay3d/粒子
gameplay::ParticleEmitter 类定义了模拟和渲染粒子系统所需的所有信息。粒子发射器可以用来表示多种视觉效果，例如烟雾、蒸汽、火焰和爆炸；以及其他大气效果，例如雨和闪电。创建后，发射器可以设置在 gameplay::Node 上以跟随一个物体，或者可以放置在场景中。
使用 ParticleEmitter::create() 方法创建粒子发射器。
此函数有 3 个重载，但您最常使用的可能是从 .particle 文件创建粒子发射器的重载，其函数签名如下
static ParticleEmitter* create (const char *url);
如果您想以编程方式创建粒子发射器，可以使用以下重载，它将创建一个未初始化的 ParticleEmitter。然后，可以使用 ParticleEmitter 类中的成员函数来配置新的粒子发射器。
static ParticleEmitter* create (const char *texturePath, TextureBlending textureBlending, unsigned int particleCountMax);
以下是使用“sample-particles”示例项目创建的 .particle 文件的注释示例，该项目是与 gameplay3d 一起打包的实用粒子编辑器。
鉴于 .particle 文件中需要完成的字段数量，并且因为在编辑时看到粒子发射器的视觉表示很有帮助，所以“sample-particles”项目可能是开始创建和配置粒子发射器的最简单方法。
particle smoke
{
sprite
{
path = smoke.png // A path to the image to use as this ParticleEmitter's texture.
width = 64 // The height of the first frame of the sprite.
height = 64 // The width of the first frame of the sprite.
blending = ADDITIVE // Other options are OPAQUE, TRANSPARENT AND MULTIPLIED.
animated = false // Specifies whether particles cycle through the sprite frames.
looped = false // Specifies whether sprites are set to loop,
frameCount = 1 // The number of frames to use for the particle emitter's sprite.
frameRandomOffset = 0 // Set to 0 for all particles to start on the first frame. Otherwise the starting frame will be a random frame not higher than this value.
frameDuration = 0 // The duration of a single sprite frame, in milliseconds.
}
particleCountMax = 5000 // The number of live particles at any one time will not exceed this value.
emissionRate = 20 // The emission rate, measured in particles per second.
ellipsoid = false // An ellipsoid particle emitter spawns particles inside a ellipsoidal domain. (Using an ellipsoidal domain
is slightly more expensive than the default cuboid domain.)
orbitPosition = false // Whether to rotate initial particle positions by the node's rotation matrix.
orbitVelocity = false // Whether to rotate initial particle velocity vectors by the node's rotation matrix.
orbitAcceleration = false // Whether to rotate initial particle acceleration vectors by the node's rotation matrix.
sizeStartMin = 3.5 // The minimum size that each particle can be at the time when it is started.
sizeStartMax = 3.5 // The maximum size that each particle can be at the time when it is started.
sizeEndMin = 15 // The minimum size that each particle can be at the end of its lifetime.
sizeEndMax = 15 // The maximum size that each particle can be at the end of its lifetime.
energyMin = 4000 // The minimum lifetime of each particle, measured in milliseconds.
energyMax = 5000 // The maximum lifetime of each particle, measured in milliseconds.
colorStart = 0.5, 0.5, 0.5, 1 // The base start color of emitted particles.
colorStartVar = 0, 0, 0, 0 // The variance of start color of emitted particles.
colorEnd = 1, 0, 0, 0 // The base end color of emitted particles.
colorEndVar = 0, 0, 0, 0 // The variance of end color of emitted particles.
position = 0, 0, 0 // The position of new particles, relative to the emitter's transform.
positionVar = 0, 0, 0 // The position variance of new particles.
velocity = 2.5, 5, 0 // The initial velocity of new particles.
velocityVar = 0, 0, 0 // The initial velocity variance of new particles.
acceleration = -10, 5, 0 // The base acceleration vector of emitted particles.
accelerationVar = 2.5, 5, 0 // The variance allowed in the acceleration of emitted particles.
rotationPerParticleSpeedMin = -1.5 // The minimum rotation speed (per particle).
rotationPerParticleSpeedMax = 1.5 // The maximum rotation speed (per particle).
editor // Particle editor-specific properties
{
cameraTranslation = -0.0200001, 4.06, 0
cameraZoom = 0, 0, 16.8
cameraRotation = 0, 0, 0, 0
sizeMax = 20
energyMax = 5000
}
}