Brighter point lights and light fade

components/sceneutil/lightmanager.cpp

@@ -56,7 +56,15 @@ namespace SceneUtil
 
         void setDiffuse(int index, const osg::Vec4& value)
         {
-            *(unsigned int*)(&(*mData)[3*index][0]) = asRGBA(value);
+            auto signedValue = value;
+            float signBit = 1.0;
+            if (value[0] < 0)
+            {
+                signedValue *= -1.0;
+                signBit = -1.0;
+            }
+            *(unsigned int*)(&(*mData)[3*index][0]) = asRGBA(signedValue);
+            *(int*)(&(*mData)[3*index][3]) = signBit;
         }
 
         void setAmbient(int index, const osg::Vec4& value)
@@ -587,8 +595,16 @@ namespace SceneUtil
         : mStartLight(0)
         , mLightingMask(~0u)
         , mSun(nullptr)
-        , mPointLightRadiusMultiplier(std::max(0.0f, Settings::Manager::getFloat("light bounds multiplier", "Shaders")))
+        , mPointLightRadiusMultiplier(std::max(0.f, Settings::Manager::getFloat("light bounds multiplier", "Shaders")))
+        , mPointLightFadeStart(0.f)
     {
+        mPointLightFadeEnd = std::max(0.f, Settings::Manager::getFloat("maximum light distance", "Shaders"));
+        if (mPointLightFadeEnd > 0)
+        {
+            mPointLightFadeStart = std::clamp(Settings::Manager::getFloat("light fade start", "Shaders"), 0.f, 1.f);
+            mPointLightFadeStart = mPointLightFadeEnd * mPointLightFadeStart;
+        }
+
         auto lightingModelString = Settings::Manager::getString("lighting method", "Shaders");
         bool validLightingModel = isValidLightingModelString(lightingModelString);
         if (!validLightingModel)
@@ -869,6 +885,19 @@ namespace SceneUtil
                 osg::BoundingSphere viewBound = osg::BoundingSphere(osg::Vec3f(0,0,0), radius * mPointLightRadiusMultiplier);
                 transformBoundingSphere(worldViewMat, viewBound);
 
+                static const float fadeDelta = mPointLightFadeEnd - mPointLightFadeStart;
+
+                if (mPointLightFadeEnd != 0.f)
+                {
+                    float fade = 1 - std::clamp((viewBound.center().length() - mPointLightFadeStart) / fadeDelta, 0.f, 1.f);
+
+                    if (fade == 0.f)
+                        continue;
+
+                    auto* light = transform.mLightSource->getLight(frameNum);
+                    light->setDiffuse(light->getDiffuse() * fade);
+                }
+
                 LightSourceViewBound l;
                 l.mLightSource = transform.mLightSource;
                 l.mViewBound = viewBound;
@@ -896,7 +925,7 @@ namespace SceneUtil
         auto* light = lightSource->getLight(frameNum);
         auto& buf = getLightBuffer(frameNum);
         buf->setDiffuse(index, light->getDiffuse());
-        buf->setAmbient(index, light->getSpecular());
+        buf->setAmbient(index, light->getAmbient());
         buf->setAttenuation(index, light->getConstantAttenuation(), light->getLinearAttenuation(), light->getQuadraticAttenuation());
         buf->setRadius(index, lightSource->getRadius());
         buf->setPosition(index, light->getPosition() * (*viewMatrix));

components/sceneutil/lightmanager.hpp

@@ -215,6 +215,8 @@ namespace SceneUtil
         LightingMethod mLightingMethod;
 
         float mPointLightRadiusMultiplier;
+        float mPointLightFadeEnd;
+        float mPointLightFadeStart;
 
         int mMaxLights;
 

files/settings-default.cfg

@@ -448,7 +448,13 @@ lighting method = experimental
 # Sets the bounding sphere multiplier of light sources, which are used to determine if an object should
 # receive lighting. Higher values will allow for smoother transitions of light sources, but may have a performance cost and
 # requires a higher number of 'max lights' set. It is recommended to keep this at 1.0 with 'legacy' lighting enabled.
-light bounds multiplier =  1.9
+light bounds multiplier =  2.0
+
+# The distance from the camera at which lights fade away completely. Set to 0 to disable fading.
+maximum light distance = 8192
+
+# Fraction of the maximum distance at which lights begin to gradually fade away.
+light fade start = 0.85
 
 # Set maximum number of lights per object. 
 # Only used when 'lighting method' is not set to 'legacy'

files/shaders/lighting.glsl

@@ -16,22 +16,21 @@ float quickstep(float x)
 #if @useUBO
 
 const uint mask = uint(0xff);
+const uvec4 shift = uvec4(uint(0), uint(8), uint(16), uint(24));
 
-vec3 unpackRGB(float data)
+vec3 unpackRGB(uint data)
 {
-    uint colors = uint(data);
-    return vec3( (((colors >>  0) & mask) / 255.0)
-                ,(((colors >>  8) & mask) / 255.0)
-                ,(((colors >> 16) & mask) / 255.0));
+    return vec3( (float(((data >> shift.x) & mask)) / 255.0)
+                ,(float(((data >> shift.y) & mask)) / 255.0)
+                ,(float(((data >> shift.z) & mask)) / 255.0));
 }
 
-vec4 unpackRGBA(float data)
+vec4 unpackRGBA(uint data)
 {
-    uint colors = uint(data);
-    return vec4( (((colors >>  0) & mask) / 255.0)
-                ,(((colors >>  8) & mask) / 255.0)
-                ,(((colors >> 16) & mask) / 255.0)
-                ,(((colors >> 24) & mask) / 255.0));
+    return vec4( (float(((data >> shift.x) & mask)) / 255.0)
+                ,(float(((data >> shift.y) & mask)) / 255.0)
+                ,(float(((data >> shift.z) & mask)) / 255.0)
+                ,(float(((data >> shift.w) & mask)) / 255.0));
 }
 
 struct LightData
@@ -74,7 +73,7 @@ void perLightSun(out vec3 ambientOut, out vec3 diffuseOut, vec3 viewPos, vec3 vi
     vec3 lightDir = normalize(getLight[0].position.xyz);
 
 #if @lightingModel == LIGHTING_MODEL_SINGLE_UBO
-    vec4 data = getLight[0].packedColors;
+    uvec4 data = getLight[0].packedColors;
     ambientOut = unpackRGB(data.y);
     vec3 sunDiffuse = unpackRGB(data.x);
 #else
@@ -108,11 +107,11 @@ void perLightPoint(out vec3 ambientOut, out vec3 diffuseOut, int lightIndex, vec
     float illumination = clamp(1.0 / (getLight[lightIndex].constantAttenuation + getLight[lightIndex].linearAttenuation * lightDistance + getLight[lightIndex].quadraticAttenuation * lightDistance * lightDistance), 0.0, 1.0);
 #else
     float illumination = clamp(1.0 / (getLight[lightIndex].attenuation.x + getLight[lightIndex].attenuation.y * lightDistance + getLight[lightIndex].attenuation.z * lightDistance * lightDistance), 0.0, 1.0);
-    illumination *= 1.0 - quickstep((lightDistance * 0.887 / getLight[lightIndex].attenuation.w) - 0.887);
+    illumination *= 1.0 - quickstep((lightDistance / (getLight[lightIndex].attenuation.w)) - 1.0);
 #endif
 
 #if @useUBO
-    vec4 data = getLight[lightIndex].packedColors;
+    uvec4 data = getLight[lightIndex].packedColors;
     ambientOut = unpackRGB(data.y) * illumination;
 #else
     ambientOut = getLight[lightIndex].ambient.xyz * illumination;
@@ -133,7 +132,7 @@ void perLightPoint(out vec3 ambientOut, out vec3 diffuseOut, int lightIndex, vec
 #endif
 
 #if @useUBO
-    diffuseOut = unpackRGB(data.x) * lambert;
+    diffuseOut =  unpackRGB(data.x) * lambert * float(int(data.w));
 #else
     diffuseOut = getLight[lightIndex].diffuse.xyz * lambert;
 #endif