Creator3D 熔解特效shader

[yans]

原理比较简单，有三：
1.将Shader里的时间转换成正小数，可以通过abs(sin(x))得到。。
2.拿三颜色中的某一个颜色值来跟时间小数做比较，如果小于时间小数，则直接丢弃。
3.再以小差值，给熔解的边框换成某一种颜色。

CCEffect %{
  techniques:
  - name: opaque
    passes:
    - vert: unlit-vs:vert
      frag: unlit-fs:frag
      properties: &props
        color:        { value: [1, 1, 1, 1], inspector: { type: color, displayName : "溶解颜色" } }
        Magnification: { value: 0.5, inspector: { displayName : "倍率" } }
        tilingOffset: { value: [1, 1, 0, 0] }
        mainTexture:  { value: grey         }
  - name: transparent
    passes:
    - vert: unlit-vs:vert
      frag: unlit-fs:frag
      blendState:
        targets:
        - blend: true
          blendSrc: src_alpha
          blendDst: one_minus_src_alpha
          blendSrcAlpha: src_alpha
          blendDstAlpha: one_minus_src_alpha
      properties: *props
}%

CCProgram unlit-vs %{
  precision mediump float;
  #include <cc-global>
  #include <cc-local-batch>
  #include <input>

  #if USE_VERTEX_COLOR
    in vec4 a_color;
    out vec4 v_color;
  #endif

  #if USE_TEXTURE
    in vec2 a_texCoord;
    out vec2 v_uv;
    uniform TexCoords {
      vec4 tilingOffset;
    };
  #endif

  highp vec4 vert () {
    vec4 position;
    CCVertInput(position);

    highp mat4 matWorld;
    CCGetWorldMatrix(matWorld);

    highp vec4 pos = cc_matProj * (cc_matView * matWorld) * position;

    #if USE_TEXTURE
      v_uv = a_texCoord;
      #if FLIP_UV
        v_uv.y = 1.0 - v_uv.y;
      #endif
      v_uv = v_uv * tilingOffset.xy + tilingOffset.zw;
    #endif

    #if USE_VERTEX_COLOR
      v_color = a_color;
    #endif

    return pos;
  }
}%

CCProgram unlit-fs %{
  precision mediump float;
  #include <output>

  #if USE_TEXTURE
    in vec2 v_uv;
    uniform sampler2D mainTexture;
  #endif

  uniform Constant {
    vec4 color;
    float Magnification;
  };

  #if USE_VERTEX_COLOR
    in vec4 v_color;
  #endif

  vec4 frag () {
    vec4 o = vec4(1, 1, 1, 1);

    #if USE_TEXTURE
      o *= texture(mainTexture, v_uv);
    #endif


    #if USE_VERTEX_COLOR
      o *= v_color;
    #endif


    float time = abs(sin(cc_time.x * Magnification));
    float height = o.g;
    if(height < time) {
      discard;
    }
    if(height < time + 0.04) {
      o.xyz = color.xyz;
    }

    return CCFragOutput(o);
  }
}%

看了下，代码没变形，就没重新传了。

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