Shader "Hidden/HDRenderPipeline/Sky/SkyBlacksmith" { SubShader { Pass { ZWrite Off ZTest Always Blend One OneMinusSrcAlpha, Zero One Cull Off HLSLPROGRAM #pragma target 4.5 #pragma only_renderers d3d11 ps4 metal // TEMP: until we go further in dev #pragma vertex Vert #pragma fragment Frag #pragma multi_compile _ ATMOSPHERICS_DEBUG #pragma multi_compile _ PERFORM_SKY_OCCLUSION_TEST #include "../../../../Core/ShaderLibrary/Color.hlsl" #include "../../../../Core/ShaderLibrary/Common.hlsl" #include "../../../../Core/ShaderLibrary/CommonLighting.hlsl" #include "../../../ShaderVariables.hlsl" TEXTURECUBE(_Cubemap); SAMPLERCUBE(sampler_Cubemap); float4x4 _PixelCoordToViewDirWS; // Actually just 3x3, but Unity can only set 4x4 // x exposure, y multiplier, z rotation float4 _SkyParam; float _SkyDepth; float _DisableSkyOcclusionTest; #define IS_RENDERING_SKY #include "AtmosphericScattering_blacksmith.hlsl" struct Attributes { uint vertexID : SV_VertexID; }; struct Varyings { float4 positionCS : SV_POSITION; }; Varyings Vert(Attributes input) { Varyings output; output.positionCS = GetFullScreenTriangleVertexPosition(input.vertexID, UNITY_RAW_FAR_CLIP_VALUE); return output; } float4 Frag(Varyings input) : SV_Target { // Points towards the camera float3 viewDirWS = normalize(mul(float3(input.positionCS.xy, 1.0), (float3x3)_PixelCoordToViewDirWS)); // Reverse it to point into the scene float3 dir = -viewDirWS; // Rotate direction float phi = DegToRad(_SkyParam.z); float cosPhi, sinPhi; sincos(phi, sinPhi, cosPhi); float3 rotDirX = float3(cosPhi, 0, -sinPhi); float3 rotDirY = float3(sinPhi, 0, cosPhi); float3 rotatedDir = float3(dot(rotDirX, dir), dir.y, dot(rotDirY, dir)); // input.positionCS is SV_Position PositionInputs posInput = GetPositionInput(input.positionCS.xy, _ScreenSize.zw); #ifdef PERFORM_SKY_OCCLUSION_TEST // Determine whether the sky is occluded by the scene geometry. // Do not perform blending with the environment map if the sky is occluded. float depthRaw = max(_SkyDepth, LOAD_TEXTURE2D(_MainDepthTexture, posInput.unPositionSS).r); float skyTexWeight = (depthRaw > _SkyDepth) ? 0.0 : 1.0; #else float depthRaw = _SkyDepth; float skyTexWeight = 1.0; #endif if (_DisableSkyOcclusionTest != 0.0) { depthRaw = _SkyDepth; skyTexWeight = 1.0; } // Since we only need the world space position, so we don't pass the view-projection matrix. UpdatePositionInput(depthRaw, _InvViewProjMatrix, k_identity4x4, posInput); float4 c1, c2, c3; VolundTransferScatter(GetAbsolutePositionWS(posInput.positionWS), c1, c2, c3); float4 coord1 = float4(c1.rgb + c3.rgb, max(0.f, 1.f - c1.a - c3.a)); float3 coord2 = c2.rgb; float sunCos = dot(normalize(dir), _SunDirection); float miePh = MiePhase(sunCos, _MiePhaseAnisotropy); float2 occlusion = float2(1.0, 1.0); // TODO. float extinction = coord1.a; float3 scatter = coord1.rgb * occlusion.x + coord2 * miePh * occlusion.y; #ifdef ATMOSPHERICS_DEBUG switch (_AtmosphericsDebugMode) { case ATMOSPHERICS_DBG_RAYLEIGH: return c1; case ATMOSPHERICS_DBG_MIE: return c2 * miePh; case ATMOSPHERICS_DBG_HEIGHT: return c3; case ATMOSPHERICS_DBG_SCATTERING: return float4(scatter, 0.0); case ATMOSPHERICS_DBG_OCCLUSION: return float4(occlusion.xy, 0.0, 0.0); case ATMOSPHERICS_DBG_OCCLUDEDSCATTERING: return float4(scatter, 0.0); } #endif float3 skyColor = float3(0.0, 0.0, 0.0); // Opacity should be proportional to extinction, but this produces wrong results. // It appears what the algorithm computes is not actually extinction. float opacity = (1.0 - extinction); if (skyTexWeight == 1.0) { skyColor = SAMPLE_TEXTURECUBE_LOD(_Cubemap, sampler_Cubemap, rotatedDir, 0).rgb; skyColor *= exp2(_SkyParam.x) * _SkyParam.y; opacity = 1.0; // Fully overwrite unoccluded scene regions. } float3 atmosphereColor = ClampToFloat16Max(skyColor * extinction + scatter); // Apply the atmosphere on top of the scene using premultiplied alpha blending. return float4(atmosphereColor, opacity); } ENDHLSL } } Fallback Off }