导入

Packages/com.jbooth.microverse/Scripts/Shaders/Generators/NormalMapGen.shader

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+Shader "Hidden/MicroVerse/NormalMapGen"
+{
+    Properties
+    {
+        _MainTex("tex", 2D) = "black" {}
+    }
+    SubShader
+    {
+        Pass
+        {
+            CGPROGRAM
+            #pragma vertex vert
+            #pragma fragment frag
+
+            #pragma shader_feature_local_fragment _ _PX
+            #pragma shader_feature_local_fragment _ _PY
+            #pragma shader_feature_local_fragment _ _NX
+            #pragma shader_feature_local_fragment _ _NY
+
+            #include_with_pragmas "UnityCG.cginc"
+
+            struct appdata
+            {
+                float4 vertex : POSITION;
+                float2 uv : TEXCOORD0;
+            };
+
+            struct v2f
+            {
+                float2 uv : TEXCOORD0;
+                float4 vertex : SV_POSITION;
+            };
+
+            sampler2D _Heightmap;
+            sampler2D _Heightmap_PX;
+            sampler2D _Heightmap_PY;
+            sampler2D _Heightmap_NX;
+            sampler2D _Heightmap_NY;
+            float4 _Heightmap_TexelSize;
+            
+
+            v2f vert(appdata v)
+            {
+                v2f o;
+                o.vertex = UnityObjectToClipPos(v.vertex);
+                o.uv = v.uv;
+                return o;
+            }
+
+
+            float3 GenerateNormal(float2 uv, float scale, float2 offset)
+            {
+                float height = UnpackHeightmap(tex2D(_Heightmap, uv));
+                float2 uvx = uv + float2(offset.x, 0.0);
+                float2 uvy = uv + float2(0.0, offset.y);
+
+                float x,y;
+
+
+                #if _PX
+                    UNITY_BRANCH
+                    if (uvx.x > 1)
+                    {
+                       uvx.x -= 1;
+                       uvx.x += offset.x;
+                       x = UnpackHeightmap(tex2D(_Heightmap_PX, uvx)); 
+                    }
+                    else
+                    {
+                       x = UnpackHeightmap(tex2D(_Heightmap, uvx));
+                    }
+                #else
+                    x = UnpackHeightmap(tex2D(_Heightmap, uvx));
+                #endif
+
+                #if _PY
+                    UNITY_BRANCH
+                    if (uvy.y > 1)
+                    {
+                       uvy.y -= 1;
+                       uvy.y += offset.y;
+                       y = UnpackHeightmap(tex2D(_Heightmap_PY, uvy)); 
+                    }
+                    else
+                    {
+                       y = UnpackHeightmap(tex2D(_Heightmap, uvy));
+                    }
+                #else
+                    y = UnpackHeightmap(tex2D(_Heightmap, uvy));
+                #endif
+
+                
+                float2 dxy = height - float2(x, y);
+
+                dxy = dxy * scale / offset.xy;
+                return normalize(float4( dxy.x, dxy.y, 1.0, height)).xzy * 0.5 + 0.5;
+            }
+
+            float SampleHeight(float2 uv)
+            {
+                #if _PX
+                    UNITY_BRANCH
+                    if (uv.x > 1)
+                    {
+                        uv.x -= 1;
+                        uv.x += _Heightmap_TexelSize.x;
+                        return UnpackHeightmap(tex2D(_Heightmap_PX, uv));   
+                    }
+                #endif
+                #if _PY
+                    UNITY_BRANCH
+                    if (uv.y > 1)
+                    {
+                       uv.y -= 1;
+                       uv.y += _Heightmap_TexelSize.y;
+                       return UnpackHeightmap(tex2D(_Heightmap_PY, uv)); 
+                    }
+                #endif
+                #if _NX
+                    UNITY_BRANCH
+                    if (uv.x < 0)
+                    {
+                        uv.x += 1;
+                        uv.x -= _Heightmap_TexelSize.x;
+                        return UnpackHeightmap(tex2D(_Heightmap_NX, uv));   
+                    }
+                #endif
+                #if _NY
+                    UNITY_BRANCH
+                    if (uv.y < 0)
+                    {
+                       uv.y += 1;
+                       uv.y -= _Heightmap_TexelSize.y;
+                       return UnpackHeightmap(tex2D(_Heightmap_NY, uv)); 
+                    }
+                #endif
+
+                return UnpackHeightmap(tex2D(_Heightmap, uv)); 
+            }
+
+            float3 GenerateNormal5Tap(float2 uv, float2 offset)
+            {
+                float height = UnpackHeightmap(tex2D(_Heightmap, uv));
+
+                float x = SampleHeight(uv + float2(offset.x, 0.0));
+                float y = SampleHeight(uv + float2(0.0, offset.y));
+                float nx = SampleHeight(uv + float2(-offset.x, 0.0));
+                float ny = SampleHeight(uv + float2(0.0, -offset.y));
+
+                float2 dxy = height - float2(x, y);
+                dxy += float2(nx, ny) - height;
+
+                dxy = dxy * 1.0f / offset.xy;
+                dxy *= 0.5;
+                return normalize(float4(dxy.x, dxy.y, 1.0, height)).xzy * 0.5 + 0.5;
+            }
+
+
+            float4 frag(v2f i) : SV_Target
+            {
+                //float3 normal = GenerateNormal(i.uv, 1, _Heightmap_TexelSize.xy);
+                float3 normal = GenerateNormal5Tap(i.uv, _Heightmap_TexelSize.xy);
+                return float4(normal, 1);
+            }
+            ENDCG
+        }
+    }
+}