add water

Assets/WaterWorks/Shaders/Water_Volume.hlsl

@@ -0,0 +1,175 @@
+#ifndef Water_Volume
+#define Water_Volume
+
+CBUFFER_START(UnityPerMaterial)
+Texture2D _MainTex;
+sampler sampler_MainTex;
+float4 Albedo;
+float density;
+float3 pos;
+float3 bounds;
+CBUFFER_END
+
+float2 random2D(float2 UV, float offset)
+{
+    float2x2 m = float2x2(15.27f, 47.63f, 99.41f, 89.98f);
+    UV = frac(sin(mul(UV, m)));
+    return float2(sin(UV.y * +offset) * 0.5f + 0.5f, cos(UV.x * offset) * 0.5f + 0.5f);
+}
+
+float random3D(float3 uv)
+{
+    float Coord = (uv.x + uv.y + uv.z);
+    float2 _uv = float2(Coord, Coord);
+    float2 noise = (frac(sin(dot(_uv, float2(12.9898, 78.233) * 2.0)) * 43758.5453));
+    return (abs(noise.x + noise.y) - 1);
+}
+
+float2 Cellular(float2 UV, float AngleOffset)
+{
+    float2 g = floor(UV);
+    float2 f = frac(UV);
+    float2 res = float2(8, 8);
+
+    [unroll]
+    for (int y = -1; y <= 1; y++)
+    {
+        [unroll]
+        for (int x = -1; x <= 1; x++)
+        {
+            float2 lattice = float2(x, y);
+            float2 offset = random2D(lattice + g, AngleOffset);
+            float dist = distance(lattice + offset, f);
+
+            if (dist < res.x)
+            {
+                res.y = length(offset);
+                res.x = dist;
+            }
+        }
+    }
+
+    return res;
+}
+
+float2 rayBoxDst(float3 boundsMin, float3 boundsMax, float3 rayOrigin, float3 invRaydir)
+{
+    float3 t0 = (boundsMin - rayOrigin) * invRaydir;
+    float3 t1 = (boundsMax - rayOrigin) * invRaydir;
+    float3 tmin = min(t0, t1);
+    float3 tmax = max(t0, t1);
+
+    float dstA = max(max(tmin.x, tmin.y), tmin.z);
+    float dstB = min(tmax.x, min(tmax.y, tmax.z));
+
+    float dstToBox = max(0, dstA);
+    float dstInsideBox = max(0, dstB - dstToBox);
+    return float2(dstToBox, dstInsideBox);
+}
+
+float3 GetRay(float2 screenPos)
+{
+    float3 viewVector = mul(unity_CameraInvProjection, float4(screenPos * 2 - 1, 0, -1));
+    float3 viewDir = mul(unity_CameraToWorld, float4(viewVector, 0));
+    float viewLength = length(viewDir);
+    float3 ray = viewDir / viewLength;
+
+    return ray;
+}
+
+float SceneDepth(float2 UV)
+{
+    return LinearEyeDepth(SHADERGRAPH_SAMPLE_SCENE_DEPTH(UV), _ZBufferParams);
+}
+
+SurfaceDescription SurfaceDescriptionFunction(SurfaceDescriptionInputs IN)
+{
+    SurfaceDescription surface = (SurfaceDescription)0;
+
+    pos.xz += _WorldSpaceCameraPos.xz;
+
+    float3 posBL = pos - bounds / 2;
+    float3 posTR = pos + bounds / 2;
+
+    float3 viewVector = mul(unity_CameraInvProjection, float4(IN.ScreenPosition.xy * 2 - 1, 0, -1));
+    float3 viewDir = mul(unity_CameraToWorld, float4(viewVector, 0));
+    float viewLength = length(viewDir);
+
+    float3 ray = GetRay(IN.ScreenPosition.xy);
+
+    float2 boxDist = rayBoxDst(posBL, posTR, _WorldSpaceCameraPos, 1 / ray);
+
+    float distToBox = boxDist.x;
+    float distInBox = boxDist.y;
+
+    float3 entryPoint = _WorldSpaceCameraPos + ray * distToBox;
+
+    float3 rayPos = entryPoint + ray * viewLength;
+
+    float depth = SceneDepth(IN.ScreenPosition.xy) * viewLength;
+
+    if (distInBox == 0 || distToBox > depth)
+    {
+        surface.BaseColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, IN.ScreenPosition.xy / IN.ScreenPosition.w);
+        return surface;
+    }
+
+    float cumulativeDensity = 0;
+    float cumulativeDensityNoNoise = 0;
+    float lighting = 0;
+    float distTravelled = 0;
+    float stepSize = 0.5;
+    int i = 0;
+    UNITY_LOOP
+        for (i = 0; i < 250 && distTravelled + distToBox < depth && distTravelled < distInBox; i++)
+        {
+            float shadowAtten = 1;
+            float shadowAttenL = 1;
+            float shadowAttenR = 1;
+            float pointDensity;
+            float distMultiplier = 1;
+
+            float yPos = rayPos.y - pos.y;
+            yPos += bounds.y / 2;
+            yPos /= bounds.y;
+            float surfaceDist = pow(yPos, 200);
+            //surfaceDist = 0;
+            yPos = 1 - yPos;
+            yPos = pow(yPos, 50);
+
+            float noiseValue = Cellular(rayPos.xz * 0.2, (_Time * 50));
+            pointDensity = clamp((density * (1 - noiseValue)) + (yPos + surfaceDist), 0, 1);
+            cumulativeDensity += pointDensity * stepSize;
+            cumulativeDensityNoNoise += 0.2 * stepSize;
+            lighting += 0.05 * (1 - noiseValue);
+
+            if (1 - exp(-cumulativeDensity) > 1)
+            {
+                break;
+            }
+
+            float jitter = 0.9;
+            float randOffset = (random3D(rayPos) * (2 * (1 - jitter))) + (jitter);
+
+            distTravelled += stepSize * randOffset;
+
+            rayPos += ray * stepSize * randOffset;
+
+            if (distTravelled > 70)
+            {
+                stepSize += 10 * distMultiplier;
+                distMultiplier += 5;
+            }
+        }
+
+    float totalDensity = exp(-cumulativeDensity);
+    float totalDensityNoNoise = 1 - exp(-cumulativeDensityNoNoise);
+    float totalLighting = pow(exp(-lighting), 0.5);
+
+    float2 refraction = sin(totalDensity) * 0.1;
+    float3 background = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, (IN.ScreenPosition.xy / IN.ScreenPosition.w) + refraction);
+
+    surface.BaseColor = lerp(background * ((totalLighting * 1) + 0.1), Albedo * (totalLighting + 0.8), (((1 - totalDensity) * (1 - density)) + density) * totalDensityNoNoise);
+    return surface;
+}
+#endif