Removed falloff distance from shader

libraries/render-utils/src/AmbientOcclusionEffect.h

@@ -79,7 +79,7 @@ public:
 
     void setRadius(float newRadius) { radius = std::max(0.01f, newRadius); emit dirty(); }
     void setObscuranceLevel(float level) { obscuranceLevel = std::max(0.01f, level); emit dirty(); }
-    void setFalloffAngle(float bias) { falloffAngle = std::max(0.0f, std::min(bias, 0.2f)); emit dirty(); }
+    void setFalloffAngle(float bias) { falloffAngle = std::max(0.0f, std::min(bias, 1.0f)); emit dirty(); }
     void setFalloffDistance(float value) { falloffDistance = std::max(0.0f, value); emit dirty(); }
     void setEdgeSharpness(float sharpness) { edgeSharpness = std::max(0.0f, (float)sharpness); emit dirty(); }
     void setBlurDeviation(float deviation) { blurDeviation = std::max(0.0f, deviation); emit dirty(); }

libraries/render-utils/src/ssao.slh

@@ -290,14 +290,14 @@ float evalVisibilitySSAO(in vec3 centerPosition, in vec3 centerNormal, in vec3 t
     return f * f * f * max((vn - getFalloffAngle()) / (epsilon + vv), 0.0);
 }
 
-float computeHorizonFromTap(vec3 tapPositionES, vec3 fragPositionES, vec3 fragNormalES, float normalizedRadius) {
+float computeHorizonFromTap(vec3 tapPositionES, vec3 fragPositionES, vec3 fragNormalES) {
     vec3 deltaVec = tapPositionES - fragPositionES;
-    float distance = abs(deltaVec.z);
+    float distanceSquared = dot(deltaVec, deltaVec);
     float rawHorizon = dot(normalize(deltaVec), fragNormalES);
+    float radiusFalloff = distanceSquared / getRadius2();
 
-    rawHorizon = (rawHorizon - getFalloffAngle()) / (1.0 - getFalloffAngle());
-    rawHorizon *= 1.0 - normalizedRadius * normalizedRadius;
-    rawHorizon *= 1.0 - smoothstep(getFalloffDistance()/2, getFalloffDistance(), distance);
+    rawHorizon = max(0.0, (rawHorizon - getFalloffAngle()) / (1.0 - getFalloffAngle()));
+    rawHorizon *= 1.0 - radiusFalloff;
 
     return rawHorizon;
 }
@@ -306,12 +306,12 @@ float computeHorizonFromTap(vec3 tapPositionES, vec3 fragPositionES, vec3 fragNo
             vec3 tap = vec3(tapPixelPos, radius);
             vec4 tapUVZ_mip = fetchTap(side, centerPixelPos, tap, imageSize);
             vec3 tapPositionES = evalEyePositionFromZeye(side.x, tapUVZ_mip.z, tapUVZ_mip.xy);
-            float rawHorizon = computeHorizonFromTap(tapPositionES, fragPositionES, fragNormalES, radius / searchRadius);
+            float rawHorizon = computeHorizonFromTap(tapPositionES, fragPositionES, fragNormalES);
 
             <$horizon$> = max(<$horizon$>, rawHorizon);
 <@endfunc@>
 
-#define SSAO_LINEAR_SAMPLING 0
+#define SSAO_LINEAR_SAMPLING 1
 
 <@func updateHorizon(horizon, deltaPixelTap)@>
     {

libraries/render-utils/src/ssao_makeOcclusion.slf

@@ -69,8 +69,7 @@ void main(void) {
 #endif
     }
 
-    visibilitySum = visibilitySum * getInvNumSamples();
-    float occlusion = clamp(1.0 - visibilitySum * getObscuranceScaling(), 0.0, 1.0);
+    float occlusion = clamp(1.0 - visibilitySum * getObscuranceScaling() * getInvNumSamples(), 0.0, 1.0);
 
      // KEEP IT for Debugging
     // Bilateral box-filter over a quad for free, respecting depth edges

scripts/developer/utilities/render/ambientOcclusionPass.qml

@@ -37,7 +37,7 @@ Rectangle {
                 "Level:obscuranceLevel:1.0:false",
                 "Num Taps:numSamples:32:true",
                 "Taps Spiral:numSpiralTurns:10.0:false",
-                "Falloff Angle:falloffAngle:0.2:false",
+                "Falloff Angle:falloffAngle:0.5:false",
                 "Falloff Distance:falloffDistance:2.0:false",
                 "Blur Edge Sharpness:edgeSharpness:1.0:false",
                 "Blur Radius:blurRadius:15.0:false",