add simple fog

Editor/assets/shaders/PBRShader_Anim.glsl

@@ -75,6 +75,9 @@ const float Epsilon = 0.00001;
 const int LightCount = 1;
 const vec3 Fdielectric = vec3(0.04);
 
+layout(location = 0) out vec4 color;
+layout(location = 1) out vec4 o_BloomColor;
+
 struct DirectionalLight {
     vec3 Direction;
     vec3 Radiance;
@@ -113,8 +116,6 @@ in VertexOutput
     vec4 FragPosLightSpace;
 } vs_Input;
 
-layout(location = 0) out vec4 color;
-layout(location = 1) out vec4 o_BloomColor;
 
 uniform DirectionalLight u_DirectionalLights;
 uniform vec3 u_CameraPosition;

Editor/assets/shaders/PBRShader_Static.glsl

@@ -61,6 +61,9 @@ const float Epsilon = 0.00001;
 const int LightCount = 1;
 const vec3 Fdielectric = vec3(0.04);
 
+layout(location = 0) out vec4 color;
+layout(location = 1) out vec4 o_BloomColor;
+
 struct DirectionalLight {
 	vec3 Direction;
 	vec3 Radiance;
@@ -100,9 +103,6 @@ in VertexOutput
 	vec4 FragPosLightSpace;
 } vs_Input;
 
-layout(location = 0) out vec4 color;
-layout(location = 1) out vec4 o_BloomColor;
-
 uniform DirectionalLight u_DirectionalLights;
 
 uniform int u_PointLightCount;

Editor/assets/shaders/SceneComposite.glsl

@@ -22,8 +22,20 @@ layout(location = 1) out vec4 o_BloomTexture;
 in vec2 v_TexCoord;
 
 uniform sampler2DMS u_Texture;
+uniform sampler2DMS u_DepthTexture;
 uniform sampler2D u_BloomTexture;
 
+uniform mat4 u_InvProjection;
+uniform mat4 u_InvView;
+
+// Fog
+uniform float u_FogEnabled;
+uniform vec3  u_FogColor;
+uniform float u_FogDensity;        // 雾密度，典型值 0.01~0.05
+uniform float u_FogHeight;         // 雾的起始高度（世界 Y 坐标），低于此高度雾最浓
+uniform float u_FogHeightFalloff;  // 高度衰减系数，值越大高度影响越剧烈（典型 0.5~2.0）
+
+
 
 uniform bool u_EnableAutoExposure;
 uniform float u_ManualExposure;
@@ -62,7 +74,7 @@ float MultiSampleDepth(sampler2DMS tex, vec2 tc)
 	ivec2 texCoord = ivec2(tc * texSize);
 	float result = 0.0;
 	for (int i = 0; i < u_TextureSamples; i++)
-		result += texelFetch(tex, texCoord, i).r;
+	result += texelFetch(tex, texCoord, i).r;
 	result /= float(u_TextureSamples);
 	return result;
 }
@@ -82,10 +94,14 @@ void main()
 		color += bloomColor;
 	}
 
+
+	float exposure = 1.0f;
 	if(u_EnableAutoExposure)
-		color *= u_Exposure;
+	exposure = u_Exposure;
 	else
-		color *= u_ManualExposure;
+	exposure = u_ManualExposure;
+	color *= exposure;
+
 
 	// Reinhard tonemapping operator.
 	// see: "Photographic Tone Reproduction for Digital Images", eq. 4
@@ -95,6 +111,49 @@ void main()
 	// Scale color by ratio of average luminances.
 	vec3 mappedColor = (mappedLuminance / luminance) * color;
 
+	if (u_FogEnabled > 0.5)
+	{
+		// 1. 获取深度并重建视空间坐标
+		float depth = MultiSampleDepth(u_DepthTexture, v_TexCoord);
+		vec4 clipPos = vec4(v_TexCoord * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
+		vec4 viewPos4 = u_InvProjection * clipPos;
+		viewPos4 /= viewPos4.w;
+		vec3 viewPos = viewPos4.xyz;          // 视空间坐标（相机为原点，Z 轴向内）
+
+		// 2. 距离雾因子（指数雾）
+		float distance = length(viewPos);
+		float distanceFactor = 1.0 - exp(-distance * u_FogDensity);
+		// 可选：指数平方雾（更平滑）
+		// float distanceFactor = 1.0 - exp(-pow(distance * u_FogDensity, 2.0));
+
+		// 3. 高度雾因子（基于世界 Y）
+		// 将视空间坐标转换到世界空间
+		vec4 worldPos4 = u_InvView* vec4(viewPos, 1.0);
+		vec3 worldPos = worldPos4.xyz / worldPos4.w;
+		float worldY = worldPos.y;
+
+		float heightFactor = 0.0;
+		if (worldY < u_FogHeight)
+		{
+			// 低于起始高度：雾最浓，因子为 1
+			heightFactor = 1.0;
+		}
+		else
+		{
+			// 高于起始高度：指数衰减，高度越高雾越淡
+			float deltaY = worldY - u_FogHeight;
+			heightFactor = exp(-deltaY * u_FogHeightFalloff);
+		}
+		// 可选：使用 clamp 限制范围
+		heightFactor = clamp(heightFactor, 0.0, 1.0);
+
+		// 4. 综合雾因子（可相乘，也可取最大值，通常相乘）
+		float fogFactor = distanceFactor * heightFactor;
+
+		// 5. 混合雾颜色（雾颜色直接使用 u_FogColor，已在 LDR 空间）
+		mappedColor = mix(mappedColor, u_FogColor, fogFactor);
+	}
+
 	// Gamma correction.
 	o_Color = vec4(pow(mappedColor, vec3(1.0 / gamma)), 1.0);