Unity Shader实现3D翻页效果

 Shader "Unlit/PaperTurnMilkShader" { Properties { //正面图 _MainTex ("Texture", 2D) = "white" {} //背面图 _SrcTex("SrcTex", 2D) = "white"{} //旋转角度 _Angle("Angle", Range(0,180)) = 0 //弯曲程度 _WeightY("Weight Y", Range(0,3)) = 0.2 //收缩程度（值越大翻页时纸张越往内部靠拢)具体情况可测试 _WeightX("Weight X", Range(0,1)) = 0 //波长（值越大翻页时的弯曲次数越多） _WaveLength("WaveLength", Range(0,2)) = 0.4 } SubShader { //关闭批处理（因为修改了顶点位置) Tags { "RenderType"="Opaque" "IgnoreProjector" = "True" "Queue" = "Geometry" "DisableBatching" = "True"} LOD 100 //渲染正面 Pass { Cull Back CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float2 uv : TEXCOORD0; float4 vertex : SV_POSITION; }; sampler2D _MainTex; float4 _MainTex_ST; float _Angle; float _WeightY; float _WeightX; float _WaveLength; v2f vert (appdata v) { v2f o; //对顶点进行往X正方向偏移5个单位是为了离开旋转中心点,不然翻页时的旋转点是会在纸张中心进行围绕Z轴旋转（Z轴是纸张垂直线） v.vertex += float4(5, 0, 0, 0); float s; float c; //使用sincos获取 sin(弧度), cos(弧度)  ，radians(角度)=弧度 ,_Angle前加负号是控制旋转方向，可根据DX是右手法则顺时针旋转，故应该逆向翻页要取负数 sincos(radians(-_Angle), s, c); //围绕Z轴旋转变换矩阵 float4x4 rotate = { c,s,0,0, -s,c,0,0, 0,0,1,0, 0,0,0,1 }; //weight：_Angle在[0,90]变换区间时，weight会从0变为1；_Angle在[90,180]变换区间时，weight会从1变为0. //weight可理解为是刚开始翻页（0°）到翻页到垂直时（90°）时，对其弯曲程度从小变大；（这个是对顶点Y值影响的结果） //同理，收缩程度也是一样道理 float weight = 1 - abs(90 - _Angle) / 90; v.vertex.y += sin(v.vertex.x * _WaveLength) * weight * _WeightY; v.vertex.x -= v.vertex.x * weight * _WeightX; //在进行偏移之后，再对顶点进行围绕Z轴旋转_Angle角度 v.vertex = mul(rotate, v.vertex); //之后要偏移回来，因为我们已经做完了上面的旋转操作了 v.vertex -= float4(5, 0, 0, 0); o.vertex = UnityObjectToClipPos(v.vertex); o.uv = TRANSFORM_TEX(v.uv, _MainTex); return o; } fixed4 frag (v2f i) : SV_Target { fixed4 col = tex2D(_MainTex, i.uv); return col; } ENDCG } //渲染背面(和上方渲染正面PASS唯一的差别是：片元着色器的采样纹理改为_SrcTex(背面图） Pass { Cull Front CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float2 uv : TEXCOORD0; float4 vertex : SV_POSITION; }; sampler2D _SrcTex; float4 _MainTex_ST; float _Angle; float _WeightY; float _WeightX; float _WaveLength; v2f vert(appdata v) { v2f o; v.vertex += float4(5, 0, 0, 0); float s; float c; //使用sincos获取 sin(弧度), cos(弧度)  ，radians(角度)=弧度 sincos(radians(-_Angle), s, c); //围绕Z轴旋转变换矩阵 float4x4 rotate = { c,s,0,0, -s,c,0,0, 0,0,1,0, 0,0,0,1 }; float weight = 1 - abs(90 - _Angle) / 90; v.vertex.y += sin(v.vertex.x * _WaveLength) * weight * _WeightY; v.vertex.x -= v.vertex.x * weight * _WeightX; v.vertex = mul(rotate, v.vertex); v.vertex -= float4(5, 0, 0, 0); o.vertex = UnityObjectToClipPos(v.vertex); o.uv = TRANSFORM_TEX(v.uv, _MainTex); return o; } fixed4 frag(v2f i) : SV_Target { fixed4 col = tex2D(_SrcTex, i.uv); return col; } ENDCG } } }