[]Laya中使用shader的问题

Laya中使用shader的教程太过简单。
能否有更详细一些的说明？


比如MultiPass如何设置等？各种着色器的输入定义，比如：
uniform vec3 iResolution; // viewport resolution (in pixels) 
uniform float iGlobalTime; // shader playback time (in seconds) 
uniform float iTimeDelta; // render time (in seconds) 
uniform int iFrame; // shader playback frame 
uniform float iChannelTime[4]; // channel playback time (in seconds) 
uniform vec3 iChannelResolution[4]; // channel resolution (in pixels) 
uniform vec4 iMouse; // mouse pixel coords. xy: current (if MLB down), zw: click uniform samplerXX 
iChannel0..3; // input channel. XX = 2D/Cube 
uniform vec4 iDate; // (year, month, day, time in seconds)