在製作一個H5遊戲項目，有需求要製作multi pass的效果，但是不知道怎麼把第一個pass的結果傳到第二個。
網上查了一下，multi-pass rendering 貌似要把第一個pass的結果另外寫到一個framebuffer，並在第二個pass 讀入。具體的語法該怎麼寫?
附上目前代碼
MultiPass.effect
CCEffect %{
techniques:
- passes:
- vert: vs
frag: fs:pass1
blendState:
targets:
- blend: true
rasterizerState:
cullMode: none
- vert: vs
frag: fs:pass2
blendState:
targets:
- blend: true
rasterizerState:
cullMode: none
properties: {
texture0: {value: white}
}
}%
CCProgram vs %{
// 省略
}%
CCProgram fs %{
precision highp float;
// #include <alpha-test>
#include <texture>
in vec4 v_color;
in vec2 v_uv0;
uniform sampler2D texture;
uniform sampler2D texture0;
vec4 pass1 () {
vec4 o = vec4(1, 1, 1, 1);
o = texture2D(texture, v_uv0);
o.rgb = o.gbr;
return o;
}
vec4 pass2 () {
vec4 o = vec4(1, 1, 1, 1);
o = texture2D(texture0, v_uv0);
return o;
}
}%
MultiPass.ts
export default class MultiPass extends cc.Component {
protected _sprite: cc.Sprite = null;
start() {
this._sprite = this.node.getComponent(cc.Sprite);
let mat = this._sprite.getMaterial(0);
mat.setProperty('texture0', this._sprite.spriteFrame.getTexture(), 1);
}
}