Add SSAO fade out distance

core/src/main/java/com/seibel/distanthorizons/core/config/Config.java

@@ -419,6 +419,14 @@ public class Config
 									"")
 							.build();
 					
+					public static ConfigEntry<Integer> fadeDistanceInBlocks = new ConfigEntry.Builder<Integer>()
+							.setMinDefaultMax(0, 1_600, 30_000_000)
+							.comment("" +
+									"The distance in blocks from the camera where the SSAO will fade out to. \n"+
+									"This is done to prevent banding and noise at extreme distances. \n"+
+									"")
+							.build();
+					
 				}
 				
 				public static class GenericRendering

core/src/main/java/com/seibel/distanthorizons/core/render/renderer/shaders/SSAOShader.java

@@ -25,8 +25,10 @@ import com.seibel.distanthorizons.core.render.glObject.shader.ShaderProgram;
 import com.seibel.distanthorizons.core.render.renderer.LodRenderer;
 import com.seibel.distanthorizons.core.render.renderer.SSAORenderer;
 import com.seibel.distanthorizons.core.render.renderer.ScreenQuad;
+import com.seibel.distanthorizons.core.util.NumberUtil;
 import com.seibel.distanthorizons.core.util.math.Mat4f;
 import com.seibel.distanthorizons.core.wrapperInterfaces.minecraft.IMinecraftGLWrapper;
+import com.seibel.distanthorizons.coreapi.util.MathUtil;
 import org.lwjgl.opengl.GL32;
 
 /**
@@ -58,6 +60,7 @@ public class SSAOShader extends AbstractShaderRenderer
 	public int uMinLight;
 	public int uBias;
 	public int uDepthMap;
+	public int uFadeDistanceInBlocks;
 	
 	
 	
@@ -81,6 +84,7 @@ public class SSAOShader extends AbstractShaderRenderer
 		this.uMinLight = this.shader.getUniformLocation("uMinLight");
 		this.uBias = this.shader.getUniformLocation("uBias");
 		this.uDepthMap = this.shader.getUniformLocation("uDepthMap");
+		this.uFadeDistanceInBlocks = this.shader.getUniformLocation("uFadeDistanceInBlocks");
 	}
 	
 	
@@ -120,6 +124,10 @@ public class SSAOShader extends AbstractShaderRenderer
 		this.shader.setUniform(this.uBias, bias.floatValue());
 		
 		GL32.glUniform1i(this.uDepthMap, 0);
+		
+		float fadeDistanceInBlocks = Config.Client.Advanced.Graphics.Ssao.fadeDistanceInBlocks.get().floatValue();
+		fadeDistanceInBlocks = MathUtil.clamp(0.0f, fadeDistanceInBlocks, Float.MAX_VALUE); // clamp to prevent accidentally setting a negative number
+		this.shader.setUniform(this.uFadeDistanceInBlocks, fadeDistanceInBlocks);
 	}
 	
 	

core/src/main/resources/assets/distanthorizons/lang/en_us.json

@@ -208,6 +208,10 @@
     "Blur Radius",
   "distanthorizons.config.client.advanced.graphics.ssao.blurRadius.@tooltip":
     "The radius, measured in pixels, that blurring is calculated for the SSAO. \nHigher numbers will reduce banding at the cost of GPU performance.",
+  "distanthorizons.config.client.advanced.graphics.ssao.fadeDistanceInBlocks":
+    "Fade Distance",
+  "distanthorizons.config.client.advanced.graphics.ssao.fadeDistanceInBlocks.@tooltip":
+    "The distance in blocks from the camera where the SSAO will fade out to. \nThis is done to prevent banding and noise at extreme distances.",
 
 
 

core/src/main/resources/shaders/ssao/ao.frag

@@ -17,6 +17,7 @@ uniform float uMinLight;
 uniform float uBias;
 uniform mat4 uInvProj;
 uniform mat4 uProj;
+uniform float uFadeDistanceInBlocks;
 
 const float EPSILON = 1.e-6;
 const float GOLDEN_ANGLE = 2.39996323;
@@ -99,16 +100,30 @@ void main()
     {
         vec3 viewPos = calcViewPosition(vec3(TexCoord, fragmentDepth));
         
-        #ifdef GL_ARB_derivative_control
-        // Get higher precision derivatives when available
-        vec3 viewNormal = cross(dFdxFine(viewPos.xyz), dFdyFine(viewPos.xyz));
-        #else
-        vec3 viewNormal = cross(dFdx(viewPos.xyz), dFdy(viewPos.xyz));
-        #endif
+        // fading is done to prevent banding/noise
+        // at super far distance
+        float distanceFromCamera = length(viewPos);
+        float fadeDistance = uFadeDistanceInBlocks;
+        if (distanceFromCamera < fadeDistance)
+        {
+            #ifdef GL_ARB_derivative_control
+            // Get higher precision derivatives when available
+            vec3 viewNormal = cross(dFdxFine(viewPos.xyz), dFdyFine(viewPos.xyz));
+            #else
+            vec3 viewNormal = cross(dFdx(viewPos.xyz), dFdy(viewPos.xyz));
+            #endif
 
-        viewNormal = normalize(viewNormal);
-
-        occlusion = GetSpiralOcclusion(TexCoord, viewPos, viewNormal);
+            viewNormal = normalize(viewNormal);
+            occlusion = GetSpiralOcclusion(TexCoord, viewPos, viewNormal);
+            
+            // linearly fade with distance
+            occlusion *= (fadeDistance - distanceFromCamera) / fadeDistance;
+        }
+        else
+        {
+            // we're out of range, no need to do any SSAO calculations
+            occlusion = 0.0;
+        }
     }
     
     fragColor = vec4(vec3(1.0 - occlusion), 1.0);