Fix sky rendering in ortho and oblique projection

#3448

Source/Engine/Level/Actors/Sky.cpp

@@ -21,7 +21,8 @@
 #endif
 
 GPU_CB_STRUCT(Data {
-    Matrix WVP;
+    Matrix WorldViewProjection;
+    Matrix InvViewProjection;
     Float3 ViewOffset;
     float Padding;
     ShaderGBufferData GBuffer;
@@ -30,9 +31,6 @@ GPU_CB_STRUCT(Data {
 
 Sky::Sky(const SpawnParams& params)
     : Actor(params)
-    , _shader(nullptr)
-    , _psSky(nullptr)
-    , _psFog(nullptr)
 {
     _drawNoCulling = 1;
     _drawCategory = SceneRendering::PreRender;
@@ -52,7 +50,6 @@ Sky::Sky(const SpawnParams& params)
 Sky::~Sky()
 {
     SAFE_DELETE_GPU_RESOURCE(_psSky);
-    SAFE_DELETE_GPU_RESOURCE(_psFog);
 }
 
 void Sky::InitConfig(ShaderAtmosphericFogData& config) const
@@ -91,7 +88,7 @@ void Sky::Draw(RenderContext& renderContext)
     if (HasContentLoaded() && EnumHasAnyFlags(renderContext.View.Flags, ViewFlags::Sky))
     {
         // Ensure to have pipeline state cache created
-        if (_psSky == nullptr || _psFog == nullptr)
+        if (_psSky == nullptr)
         {
             const auto shader = _shader->GetShader();
 
@@ -113,21 +110,6 @@ void Sky::Draw(RenderContext& renderContext)
                     LOG(Warning, "Cannot create graphics pipeline state object for '{0}'.", ToString());
                 }
             }
-            if (_psFog == nullptr)
-            {
-                _psFog = GPUDevice::Instance->CreatePipelineState();
-
-                GPUPipelineState::Description psDesc = GPUPipelineState::Description::DefaultFullscreenTriangle;
-                psDesc.PS = shader->GetPS("PS_Fog");
-                psDesc.DepthWriteEnable = false;
-                psDesc.DepthClipEnable = false;
-                psDesc.BlendMode = BlendingMode::Additive;
-
-                if (_psFog->Init(psDesc))
-                {
-                    LOG(Warning, "Cannot create graphics pipeline state object for '{0}'.", ToString());
-                }
-            }
         }
 
         // Register for the sky and fog pass
@@ -139,7 +121,6 @@ void Sky::Draw(RenderContext& renderContext)
 
 void Sky::Serialize(SerializeStream& stream, const void* otherObj)
 {
-    // Base
     Actor::Serialize(stream, otherObj);
 
     SERIALIZE_GET_OTHER_OBJ(Sky);
@@ -152,7 +133,6 @@ void Sky::Serialize(SerializeStream& stream, const void* otherObj)
 
 void Sky::Deserialize(DeserializeStream& stream, ISerializeModifier* modifier)
 {
-    // Base
     Actor::Deserialize(stream, modifier);
 
     DESERIALIZE_MEMBER(Sun, SunLight);
@@ -173,39 +153,7 @@ bool Sky::IntersectsItself(const Ray& ray, Real& distance, Vector3& normal)
 
 void Sky::DrawFog(GPUContext* context, RenderContext& renderContext, GPUTextureView* output)
 {
-    // Get precomputed cache and bind it to the pipeline
+    MISSING_CODE("sky fog");
-    AtmosphereCache cache;
-    if (!AtmospherePreCompute::GetCache(&cache))
-        return;
-    context->BindSR(4, cache.Transmittance);
-    context->BindSR(5, cache.Irradiance);
-    context->BindSR(6, cache.Inscatter->ViewVolume());
-
-    // Bind GBuffer inputs
-    context->BindSR(0, renderContext.Buffers->GBuffer0);
-    context->BindSR(1, renderContext.Buffers->GBuffer1);
-    context->BindSR(2, renderContext.Buffers->GBuffer2);
-    context->BindSR(3, renderContext.Buffers->DepthBuffer);
-
-    // Setup constants data
-    Data data;
-    GBufferPass::SetInputs(renderContext.View, data.GBuffer);
-    data.ViewOffset = renderContext.View.Origin + GetPosition();
-    InitConfig(data.Fog);
-    data.Fog.AtmosphericFogSunPower *= SunLight ? SunLight->Brightness : 1.0f;
-    bool useSpecularLight = EnumHasAnyFlags(renderContext.View.Flags, ViewFlags::SpecularLight);
-    if (!useSpecularLight)
-    {
-        data.Fog.AtmosphericFogSunDiscScale = 0;
-    }
-
-    // Bind pipeline
-    auto cb = _shader->GetShader()->GetCB(0);
-    context->UpdateCB(cb, &data);
-    context->BindCB(0, cb);
-    context->SetState(_psFog);
-    context->SetRenderTarget(output);
-    context->DrawFullscreenTriangle();
 }
 
 bool Sky::IsDynamicSky() const
@@ -231,14 +179,14 @@ void Sky::ApplySky(GPUContext* context, RenderContext& renderContext, const Matr
     // Setup constants data
     Matrix m;
     Data data;
-    Matrix::Multiply(world, renderContext.View.Frustum.GetMatrix(), m);
+    Matrix::Multiply(world, renderContext.View.ViewProjection(), m);
-    Matrix::Transpose(m, data.WVP);
+    Matrix::Transpose(m, data.WorldViewProjection);
+    Matrix::Transpose(renderContext.View.IVP, data.InvViewProjection);
     GBufferPass::SetInputs(renderContext.View, data.GBuffer);
     data.ViewOffset = renderContext.View.Origin + GetPosition();
     InitConfig(data.Fog);
     //data.Fog.AtmosphericFogSunPower *= SunLight ? SunLight->Brightness : 1.0f;
-    bool useSpecularLight = EnumHasAnyFlags(renderContext.View.Flags, ViewFlags::SpecularLight);
+    if (EnumHasNoneFlags(renderContext.View.Flags, ViewFlags::SpecularLight))
-    if (!useSpecularLight)
     {
         // Hide sun disc if specular light is disabled
         data.Fog.AtmosphericFogSunDiscScale = 0;
@@ -253,11 +201,8 @@ void Sky::ApplySky(GPUContext* context, RenderContext& renderContext, const Matr
 
 void Sky::EndPlay()
 {
-    // Cleanup
     SAFE_DELETE_GPU_RESOURCE(_psSky);
-    SAFE_DELETE_GPU_RESOURCE(_psFog);
 
-    // Base
     Actor::EndPlay();
 }
 
@@ -268,7 +213,6 @@ void Sky::OnEnable()
     GetSceneRendering()->AddViewportIcon(this);
 #endif
 
-    // Base
     Actor::OnEnable();
 }
 
@@ -279,13 +223,11 @@ void Sky::OnDisable()
 #endif
     GetSceneRendering()->RemoveActor(this, _sceneRenderingKey);
 
-    // Base
     Actor::OnDisable();
 }
 
 void Sky::OnTransformChanged()
 {
-    // Base
     Actor::OnTransformChanged();
 
     _box = BoundingBox(_transform.Translation);

Source/Engine/Level/Actors/Sky.h

@@ -20,8 +20,7 @@ class FLAXENGINE_API Sky : public Actor, public IAtmosphericFogRenderer, public
     DECLARE_SCENE_OBJECT(Sky);
 private:
     AssetReference<Shader> _shader;
-    GPUPipelineState* _psSky;
+    GPUPipelineState* _psSky = nullptr;
-    GPUPipelineState* _psFog;
     int32 _sceneRenderingKey = -1;
 
 public:
@@ -57,7 +56,6 @@ private:
     void OnShaderReloading(Asset* obj)
     {
         _psSky = nullptr;
-        _psFog = nullptr;
     }
 #endif
     void InitConfig(ShaderAtmosphericFogData& config) const;

Source/Engine/Renderer/GBufferPass.cpp

@@ -19,6 +19,7 @@
 #include "Engine/Content/Content.h"
 #include "Engine/Content/Assets/Model.h"
 #include "Engine/Level/Actors/Decal.h"
+#include "Engine/Level/Actors/Sky.h"
 #include "Engine/Engine/Engine.h"
 
 GPU_CB_STRUCT(GBufferPassData {
@@ -416,8 +417,17 @@ void GBufferPass::DrawSky(RenderContext& renderContext, GPUContext* context)
 
     // Calculate sphere model transform to cover far plane
     Matrix m1, m2;
-    Matrix::Scaling(renderContext.View.Far / ((float)box.GetSize().Y * 0.5f) * 0.95f, m1); // Scale to fit whole view frustum
+    float size = renderContext.View.Far;
-    Matrix::CreateWorld(renderContext.View.Position, Float3::Up, Float3::Backward, m2); // Rotate sphere model
+    Float3 origin = renderContext.View.Position;
+    if (dynamic_cast<Sky*>(renderContext.List->Sky)) // TODO: refactor sky rendering (eg. let sky draw with custom projection)
+    {
+        BoundingSphere frustumBounds;
+        renderContext.View.CullingFrustum.GetSphere(frustumBounds);
+        origin = frustumBounds.Center;
+        size = frustumBounds.Radius;
+    }
+    Matrix::Scaling(size / ((float)box.GetSize().Y * 0.5f) * 0.95f, m1); // Scale to fit whole view frustum
+    Matrix::CreateWorld(origin, Float3::Up, Float3::Backward, m2); // Rotate sphere model
     m1 *= m2;
 
     // Draw sky

Source/Shaders/Sky.shader

@@ -7,7 +7,8 @@
 #include "./Flax/AtmosphereFog.hlsl"
 
 META_CB_BEGIN(0, Data)
-float4x4 WVP;
+float4x4 WorldViewProjection;
+float4x4 InvViewProjection;
 float3 ViewOffset;
 float Padding;
 GBufferData GBuffer;
@@ -18,7 +19,7 @@ DECLARE_GBUFFERDATA_ACCESS(GBuffer)
 
 struct MaterialInput
 {
-	float4 Position  : SV_Position;
+	float4 Position : SV_Position;
 	float4 ScreenPos : TEXCOORD0;
 };
 
@@ -30,12 +31,9 @@ MaterialInput VS(ModelInput_PosOnly input)
 	MaterialInput output;
 
 	// Compute vertex position
-	output.Position = mul(float4(input.Position.xyz, 1), WVP);
+	output.Position = mul(float4(input.Position.xyz, 1), WorldViewProjection);
 	output.ScreenPos = output.Position;
 
-	// Place pixels on the far plane
-	output.Position = output.Position.xyzz;
-
 	return output;
 }
 
@@ -45,15 +43,15 @@ GBufferOutput PS_Sky(MaterialInput input)
 {
 	GBufferOutput output;
 
-	// Obtain UVs corresponding to the current pixel
+    // Calculate view vector (unproject at the far plane)
-	float2 uv = (input.ScreenPos.xy / input.ScreenPos.w) * float2(0.5, -0.5) + float2(0.5, 0.5);
+	GBufferData gBufferData = GetGBufferData();
+	float4 clipPos = float4(input.ScreenPos.xy / input.ScreenPos.w, 1.0, 1.0);
+	clipPos = mul(clipPos, InvViewProjection);
+	float3 worldPos = clipPos.xyz / clipPos.w;
+    float3 viewVector = normalize(worldPos - gBufferData.ViewPos);
 
 	// Sample atmosphere color
-	GBufferData gBufferData = GetGBufferData();
+    float4 color = GetAtmosphericFog(AtmosphericFog, gBufferData.ViewFar, gBufferData.ViewPos + ViewOffset, viewVector, gBufferData.ViewFar, float3(0, 0, 0));
-	float3 vsPos = GetViewPos(gBufferData, uv, LinearZ2DeviceDepth(gBufferData, 1));
-	float3 wsPos = mul(float4(vsPos, 1), gBufferData.InvViewMatrix).xyz;
-	float3 viewVector = wsPos - gBufferData.ViewPos;
-	float4 color = GetAtmosphericFog(AtmosphericFog, gBufferData.ViewFar, wsPos + ViewOffset, gBufferData.ViewPos + ViewOffset);
 
 	// Pack GBuffer
 	output.Light = color;
@@ -64,36 +62,3 @@ GBufferOutput PS_Sky(MaterialInput input)
 
 	return output;
 }
-
-META_PS(true, FEATURE_LEVEL_ES2)
-float4 PS_Fog(Quad_VS2PS input) : SV_Target0
-{
-	float4 result;
-	/*
-	// Sample GBuffer
-	GBufferSample gBuffer = SampleGBuffer(GBuffer, input.TexCoord);
-	
-	// TODO: set valid scene color for better inscatter reflectance
-	//float3 sceneColor = gBuffer.Color * AtmosphericFogDensityOffset;
-	float3 sceneColor = float3(0, 0, 0);
-	
-	// Sample atmosphere color
-	float3 viewVector = gBuffer.WorldPos - GBuffer.ViewPos;
-	float SceneDepth = length(ViewVector);
-	result = GetAtmosphericFog(AtmosphericFog, GBuffer.ViewFar, GBuffer.ViewPos, viewVector, SceneDepth, sceneColor);
-	
-	//result.rgb = normalize(ViewVector);
-	//result.rgb = ViewVector;
-	//result.rgb = SceneDepth.xxx / GBuffer.ViewFar * 0.5f;
-	
-	//result = float4(input.TexCoord, 0, 1);
-	//result = AtmosphereTransmittanceTexture.Sample(SamplerLinearClamp, input.TexCoord);
-	//result = float4(AtmosphereIrradianceTexture.Sample(SamplerLinearClamp, input.TexCoord).rgb*5.0, 1.0);
-	//result = AtmosphereInscatterTexture.Sample(SamplerLinearClamp, float3(input.TexCoord.xy, (AtmosphericFogSunDirection.x+1.0)/2.0));
-	*/
-
-	// TODO: finish fog
-	result = float4(1, 0, 0, 1);
-
-	return result;
-}