+ 水体的透明以及雾效果

Author: [email protected]

Chapter 10 Blending/Core/Shaders/defaultPS.hlsl

@@ -29,8 +29,16 @@ cbuffer cbPass : register(b1)
 {
     float4x4 gViewProj;
     float3 gEyePosW;
+    float pad;
     float4 gAmbientLight;
 
+    // Allow application to change fog parameters once per frame.
+    // For example, we may only use fog for certain times of day.
+    float4 gFogColor;
+    float gFogStart;
+    float gFogRange;
+    float2 pad2;
+
     // Indices [0, NUM_DIR_LIGHTS) are directional lights;
     // indices [NUM_DIR_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHTS) are point lights;
     // indices [NUM_DIR_LIGHTS+NUM_POINT_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHT+NUM_SPOT_LIGHTS)
@@ -69,7 +77,9 @@ float4 main(VertexOut pin) : SV_Target0
     pin.NormalW = normalize(pin.NormalW);
 
     // Vector from point being lit to eye. 
-    float3 toEyeW = normalize(gEyePosW - pin.PosW);
+    float3 toEyeW = gEyePosW - pin.PosW;
+    float distToEye = length(toEyeW);
+    toEyeW /= distToEye; // normalize
 
     // Indirect lighting.
     float4 ambient = gAmbientLight * diffuseAlbedo;
@@ -82,6 +92,13 @@ float4 main(VertexOut pin) : SV_Target0
 
     float4 litColor = ambient + directLight;
 
+    // 雾，如果雾的颜色alpha为0，则不处理
+    if (gFogColor.a > 0)
+    {
+        float fogAmount = saturate((distToEye - gFogStart) / gFogRange);
+        litColor = lerp(litColor, gFogColor, fogAmount);
+    }
+    
     // Common convention to take alpha from diffuse material.
     litColor.a = diffuseAlbedo.a;
 

Chapter 10 Blending/GameApp.cpp

@@ -90,6 +90,17 @@ void GameApp::Startup(void)
     alphaTestPSO.SetRasterizerState(raster);
     alphaTestPSO.Finalize();
     m_mapPSO[E_EPT_ALPHATEST] = alphaTestPSO;
+
+    // 透明混合PSO
+    GraphicsPSO transparentPSO = defaultPSO;
+    auto blend = Graphics::BlendTraditional;
+    blend.RenderTarget[0].DestBlendAlpha = D3D12_BLEND_ZERO;
+    transparentPSO.SetBlendState(blend);
+    transparentPSO.Finalize();
+    m_mapPSO[E_EPT_TRANSPARENT] = transparentPSO;
+
+    // 初始化底色
+    Graphics::g_SceneColorBuffer.SetClearColor({ 0.7f, 0.7f, 0.7f });
 }
 
 void GameApp::Cleanup(void)
@@ -515,8 +526,8 @@ void GameApp::buildLandAndWaves()
     m_renderItemWaves.modelToWorld = Transpose(Matrix4(kIdentity));
     m_renderItemWaves.texTransform = Transpose(Matrix4(AffineTransform(Matrix3::MakeScale(5.0f, 5.0f, 1.0f))));
     m_renderItemWaves.matTransform = Transpose(Matrix4(kIdentity));
-    m_renderItemWaves.diffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
-    m_renderItemWaves.fresnelR0 = XMFLOAT3(0.2f, 0.2f, 0.2f);
+    m_renderItemWaves.diffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 0.5f);
+    m_renderItemWaves.fresnelR0 = XMFLOAT3(0.12f, 0.1f, 0.1f);
     m_renderItemWaves.roughness = 0.0f;
     m_renderItemWaves.srv = MatTextures[1]->GetSRV();
 
@@ -580,20 +591,7 @@ void GameApp::renderLandAndWaves(GraphicsContext& gfxContext)
         // 绘制
         gfxContext.DrawIndexedInstanced(m_IndexBufferLand.GetElementCount(), 1, 0, 0, 0);
     }
-    
-
-    // waves
-    {
-        gfxContext.SetIndexBuffer(m_IndexBufferWaves.IndexBufferView());
-
-        gfxContext.SetDynamicVB(0, m_verticesWaves.size(), sizeof(Vertex), m_verticesWaves.data());
-
-        setShaderParam(gfxContext, m_renderItemWaves);
-
-        // 绘制
-        gfxContext.DrawIndexedInstanced(m_IndexBufferWaves.GetElementCount(), 1, 0, 0, 0);
-    }
-    
+   
     // box
     {
         // 设置顶点视图
@@ -608,6 +606,20 @@ void GameApp::renderLandAndWaves(GraphicsContext& gfxContext)
         // 绘制
         gfxContext.DrawIndexedInstanced(m_IndexBufferBox.GetElementCount(), 1, 0, 0, 0);
     }
+
+    // waves
+    {
+        gfxContext.SetIndexBuffer(m_IndexBufferWaves.IndexBufferView());
+
+        gfxContext.SetDynamicVB(0, m_verticesWaves.size(), sizeof(Vertex), m_verticesWaves.data());
+
+        setShaderParam(gfxContext, m_renderItemWaves);
+
+        gfxContext.SetPipelineState(m_mapPSO[E_EPT_TRANSPARENT]);
+
+        // 绘制
+        gfxContext.DrawIndexedInstanced(m_IndexBufferWaves.GetElementCount(), 1, 0, 0, 0);
+    }
 }
 
 void GameApp::UpdateWaves(float deltaT)

Chapter 10 Blending/GameApp.h

@@ -64,8 +64,9 @@ class GameApp : public GameCore::IGameApp
     enum ePSOType
     {
         E_EPT_DEFAULT = 1,
-        E_EPT_WIREFRAME = 2,
-        E_EPT_ALPHATEST = 3,
+        E_EPT_WIREFRAME = 2,        // 只画线
+        E_EPT_ALPHATEST = 3,        // 绘制透明类物体，去掉背面剔除
+        E_EPT_TRANSPARENT = 4,      // 半透混合效果
     };
     std::unordered_map<int, GraphicsPSO> m_mapPSO;
 

Chapter 10 Blending/d3dUtil.h

@@ -29,6 +29,11 @@ __declspec(align(16)) struct PassConstants
     Vector3 eyePosW = { 0.0f, 0.0f, 0.0f };     // 观察点也就是摄像机位置
     Vector4 ambientLight = { 0.0f, 0.0f, 0.0f, 1.0f };
 
+    Vector4 FogColor = { 0.7f, 0.7f, 0.7f, 0.3f };
+    float gFogStart = 40.0f;
+    float gFogRange = 150.0f;
+    XMFLOAT2 pad;
+
     // Indices [0, NUM_DIR_LIGHTS) are directional lights;
     // indices [NUM_DIR_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHTS) are point lights;
     // indices [NUM_DIR_LIGHTS+NUM_POINT_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHT+NUM_SPOT_LIGHTS)