Unity3D学习笔记（三十七）：顶点偏移和溶解

顶点偏移

沿向量方向偏移，沿自身坐标系方向偏移

沿法线方向偏移，球体放大，立方体拆分

Shader "Lesson/VFVertOffsetVertex" {
    Properties {
        _Offset ("偏移量", float) = 1
    }
    SubShader {
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
           
            float _Offset;
           
            struct m2v
            {
                float4 vex : POSITION;
                float3 normal : NORMAL;
            };
            struct v2f
            {
                float4 position : SV_POSITION;
            };
            v2f vert(m2v v)
            {
                v2f f;
                //v.vex.xyz += float3(1, 0, 0);//沿向量偏移
                v.vex.xyz += v.normal * _Offset;//沿法线偏移
                f.position = UnityObjectToClipPos(v.vex);
                return f;
            }
            fixed4 frag(v2f f) : SV_Target
            {
                return fixed4(1,0,0,1);
            }
            ENDCG
        }
    }
    FallBack "Diffuse"
}

溶解效果

Shader "Lesson/VFVertOffsetVertex" {
    Properties {
        _MainTex("纹理", 2D) = ""{}
        _DissTex("噪声图", 2D) = ""{}
        _MarginColor("边缘的颜色", Color) = (1,1,1,1)
        _DissValue("阈值", Range(0, 1)) = 0
        _MarginValue("边缘的宽度", Range(0, 1)) = 0.1
    }
    SubShader{
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            sampler2D _MainTex;
            sampler2D _DissTex;
            float _DissValue;
            float _MarginValue;
            fixed4 _MarginColor;
           
            struct m2v
            {
                float4 vex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f
            {
                float4 position : SV_POSITION;
                float2 uv : TEXCOORD0;
            };
              
            v2f vert(m2v v)
            {
                v2f f;
                f.position = UnityObjectToClipPos(v.vex);
                f.uv = v.uv;
                return f;
            }
            fixed4 frag(v2f f) : SV_Target
            {
                fixed4 texColor = tex2D(_MainTex, f.uv);
                fixed4 dissColor = tex2D(_DissTex, f.uv);//通过UV获取噪声图上的颜色
                if (dissColor.r < _DissValue)//借助噪声图的颜色的一个通道去做判断
                {
                    discard;//裁剪掉小于阈值的部分
                }
                float lerpValue = _DissValue / dissColor.r;//边缘过渡
                        
                if (lerpValue < 1 && lerpValue > (1 - _MarginValue))
                {
                    return _MarginColor;
                }                                         
                return texColor;
            }
            ENDCG
        }
    }
    FallBack "Diffuse"
}