exposing one more parameter

examples/utilities/tools/renderEngineDebug.js

@@ -129,6 +129,11 @@ panel.newCheckbox("Ambient Occlusion Dithering",
     function() { return Render.ambientOcclusion.ditheringEnabled; },
     function (value) { return (value); });
 
+panel.newSlider("Ambient Occlusion Falloff Bias", 0.0, 0.2,
+    function (value) { Render.ambientOcclusion.falloffBias = value; },
+    function() { return Render.ambientOcclusion.falloffBias; },
+    function (value) { return (value.toFixed(2)); });
+
 panel.newSlider("Ambient Occlusion Edge Sharpness", 0.0, 1.0,
     function (value) { Render.ambientOcclusion.edgeSharpness = value; },
     function() { return Render.ambientOcclusion.edgeSharpness; },

libraries/render-utils/src/AmbientOcclusionEffect.cpp

@@ -246,6 +246,15 @@ void AmbientOcclusionEffect::setDithering(bool enabled) {
     }
 }
 
+void AmbientOcclusionEffect::setFalloffBias(float bias) {
+    bias = std::max(0.0f, std::min(bias, 0.2f));
+    if (bias != getFalloffBias()) {
+        auto& current = _parametersBuffer.edit<Parameters>()._ditheringInfo;
+        current.z = (float)bias;
+    }
+}
+
+
 void AmbientOcclusionEffect::setNumSamples(int numSamples) {
     numSamples = std::max(1.f, (float) numSamples);
     if (numSamples != getNumSamples()) {

libraries/render-utils/src/AmbientOcclusionEffect.h

@@ -37,6 +37,10 @@ public:
     void setDithering(bool enabled);
     bool isDitheringEnabled() const { return _parametersBuffer.get<Parameters>()._ditheringInfo.x; }
 
+    // Faloff Bias
+    void setFalloffBias(float bias);
+    int getFalloffBias() const { return (int)_parametersBuffer.get<Parameters>()._ditheringInfo.z; }
+
     // Number of samples per pixel to evaluate the Obscurance
     void setNumSamples(int numSamples);
     int getNumSamples() const { return (int)_parametersBuffer.get<Parameters>()._sampleInfo.x; }
@@ -94,8 +98,8 @@ private:
         glm::vec4 _resolutionInfo{ -1.0, 0.0, 0.0, 0.0 };
         // radius info is { R, R^2, 1 / R^6, ObscuranceScale}
         glm::vec4 _radiusInfo{ 0.5, 0.5 * 0.5, 1.0 / (0.25 * 0.25 * 0.25), 1.0 };
-        // Dithering info
-        glm::vec4 _ditheringInfo{ 0.0, 0.0, 0.0, 0.0 };
+        // Dithering info 
+        glm::vec4 _ditheringInfo{ 0.0, 0.0, 0.01, 0.0 };
         // Sampling info
         glm::vec4 _sampleInfo{ 11.0, 1.0/11.0, 7.0, 1.0 };
         // Blurring info

libraries/render-utils/src/RenderDeferredTask.cpp

@@ -180,6 +180,7 @@ void RenderDeferredTask::run(const SceneContextPointer& sceneContext, const Rend
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setNumSamples(renderContext->getAmbientOcclusion().numSamples);
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setNumSpiralTurns(renderContext->getAmbientOcclusion().numSpiralTurns);
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setDithering(renderContext->getAmbientOcclusion().ditheringEnabled);
+        _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setFalloffBias(renderContext->getAmbientOcclusion().falloffBias);
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setEdgeSharpness(renderContext->getAmbientOcclusion().edgeSharpness);
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setBlurRadius(renderContext->getAmbientOcclusion().blurRadius);
         _jobs[_occlusionJobIndex].edit<AmbientOcclusionEffect>().setBlurDeviation(renderContext->getAmbientOcclusion().blurDeviation);

libraries/render-utils/src/RenderScriptingInterface.h

@@ -76,6 +76,7 @@ namespace RenderScripting {
         Q_PROPERTY(int numSamples MEMBER numSamples)
         Q_PROPERTY(float numSpiralTurns MEMBER numSpiralTurns)
         Q_PROPERTY(bool ditheringEnabled MEMBER ditheringEnabled)
+        Q_PROPERTY(float falloffBias MEMBER falloffBias)
         Q_PROPERTY(float edgeSharpness MEMBER edgeSharpness)
         Q_PROPERTY(int blurRadius MEMBER blurRadius)
         Q_PROPERTY(float blurDeviation MEMBER blurDeviation)

libraries/render-utils/src/ssao.slh

@@ -113,6 +113,9 @@ float getFrameDithering() {
     return params._ditheringInfo.y;
 }
 
+float getFalloffBias() {
+    return params._ditheringInfo.z;
+}
 
 float getNumSamples() {
     return params._sampleInfo.x;

libraries/render-utils/src/ssao_makeOcclusion.slf

@@ -84,13 +84,10 @@ float sampleAO(in ivec2 side, in ivec2 ssC, in vec3 C, in vec3 n_C, in float ssD
     float vv = dot(v, v);
     float vn = dot(v, n_C);
 
-    const float bias =  0.01;
-    const float epsilon = 0.01;
-    float radius2 = getRadius2();
-
     // Fall off function as recommended in SAO paper
-    float f = max(radius2 - vv, 0.0);
-    return f * f * f * max((vn - bias) / (epsilon + vv), 0.0);
+    const float epsilon = 0.01;
+    float f = max(getRadius2() - vv, 0.0);
+    return f * f * f * max((vn - getFalloffBias()) / (epsilon + vv), 0.0);
 }
 
 void main(void) {

libraries/render/src/render/Context.h

@@ -80,6 +80,7 @@ public:
         int numSamples = 11; // Num Samples per pixel
         float numSpiralTurns = 7.0f;
         bool ditheringEnabled = true;
+        float falloffBias = 0.01f;
         float edgeSharpness = 1.0f;
         int blurRadius = 4;
         float blurDeviation = 2.5f;