Support point specular lighting (#6188)

Fix passing light specular colors with shader lighting methods (with help from wazabear)

CHANGELOG.md

@@ -95,6 +95,7 @@
     Feature #5492: Let rain and snow collide with statics
     Feature #6149: Dehardcode Lua API_REVISION
     Feature #6152: Playing music via lua scripts
+    Feature #6188: Specular lighting from point light sources
     Feature #6447: Add LOD support to Object Paging
     Feature #6491: Add support for Qt6
     Feature #6556: Lua API for sounds

components/sceneutil/lightcontroller.cpp

@@ -36,9 +36,11 @@ namespace SceneUtil
         // if (time == mLastTime)
         //    return;
 
+        osg::Light* light = node->getLight(nv->getTraversalNumber());
+
         if (mType == LT_Normal)
         {
-            node->getLight(nv->getTraversalNumber())->setDiffuse(mDiffuseColor);
+            light->setDiffuse(mDiffuseColor);
             traverse(node, nv);
             return;
         }
@@ -63,7 +65,10 @@ namespace SceneUtil
                 mPhase = mPhase <= 0.5f ? 1.f : 0.25f;
         }
 
-        node->getLight(nv->getTraversalNumber())->setDiffuse(mDiffuseColor * mBrightness * node->getActorFade());
+        osg::Vec4f result = mDiffuseColor * mBrightness * node->getActorFade();
+
+        light->setDiffuse(result);
+        light->setSpecular(result);
 
         traverse(node, nv);
     }

components/sceneutil/lightmanager.cpp

@@ -536,6 +536,7 @@ namespace SceneUtil
                 configurePosition(lightMat, light->getPosition() * mViewMatrix);
                 configureAmbient(lightMat, light->getAmbient());
                 configureDiffuse(lightMat, light->getDiffuse());
+                configureSpecular(lightMat, light->getSpecular());
                 configureAttenuation(lightMat, light->getConstantAttenuation(), light->getLinearAttenuation(),
                     light->getQuadraticAttenuation(), lightList[i]->mLightSource->getRadius());
 
@@ -1214,6 +1215,7 @@ namespace SceneUtil
         auto& buf = getUBOManager()->getLightBuffer(frameNum);
         buf->setDiffuse(index, light->getDiffuse());
         buf->setAmbient(index, light->getAmbient());
+        buf->setSpecular(index, light->getSpecular());
         buf->setAttenuationRadius(index,
             osg::Vec4(light->getConstantAttenuation(), light->getLinearAttenuation(), light->getQuadraticAttenuation(),
                 lightSource->getRadius()));

components/sceneutil/lightutil.cpp

@@ -124,7 +124,7 @@ namespace SceneUtil
         }
         light->setDiffuse(diffuse);
         light->setAmbient(ambient);
-        light->setSpecular(osg::Vec4f(0, 0, 0, 0));
+        light->setSpecular(diffuse); // ESM format doesn't provide specular
 
         lightSource->setLight(light);
 

files/shaders/compatibility/bs/default.frag

@@ -95,7 +95,7 @@ void main()
 #endif
 
     if (matSpec != vec3(0.0))
-        gl_FragData[0].xyz += getSpecular(viewNormal, normalize(passViewPos.xyz), shininess, matSpec) * shadowing;
+        gl_FragData[0].xyz += matSpec * getSpecular(viewNormal, passViewPos, shininess, shadowing);
 
     gl_FragData[0] = applyFogAtDist(gl_FragData[0], euclideanDepth, linearDepth, far);
 

files/shaders/compatibility/objects.frag

@@ -242,7 +242,7 @@ vec3 viewNormal = normalize(gl_NormalMatrix * normal);
     matSpec *= specStrength;
     if (matSpec != vec3(0.0))
     {
-        gl_FragData[0].xyz += getSpecular(viewNormal, viewVec, shininess, matSpec) * shadowing;
+        gl_FragData[0].xyz += matSpec * getSpecular(viewNormal, passViewPos, shininess, shadowing);
     }
 
     gl_FragData[0] = applyFogAtPos(gl_FragData[0], passViewPos, far);

files/shaders/compatibility/terrain.frag

@@ -108,7 +108,7 @@ void main()
 
     if (matSpec != vec3(0.0))
     {
-        gl_FragData[0].xyz += getSpecular(viewNormal, normalize(passViewPos), shininess, matSpec) * shadowing;
+        gl_FragData[0].xyz += matSpec * getSpecular(viewNormal, passViewPos, shininess, shadowing);
     }
 
     gl_FragData[0] = applyFogAtDist(gl_FragData[0], euclideanDepth, linearDepth, far);

files/shaders/lib/light/lighting.glsl

@@ -90,15 +90,47 @@ void doLighting(vec3 viewPos, vec3 viewNormal, out vec3 diffuseLight, out vec3 a
     }
 }
 
-vec3 getSpecular(vec3 viewNormal, vec3 viewDirection, float shininess, vec3 matSpec)
+float calcSpecIntensity(vec3 viewNormal, vec3 viewDir, float shininess, vec3 lightDir)
 {
-    vec3 lightDir = normalize(lcalcPosition(0));
-    float NdotL = dot(viewNormal, lightDir);
-    if (NdotL <= 0.0)
-        return vec3(0.0);
-    vec3 halfVec = normalize(lightDir - viewDirection);
-    float NdotH = dot(viewNormal, halfVec);
-    return pow(max(NdotH, 0.0), max(1e-4, shininess)) * lcalcSpecular(0).xyz * matSpec;
+    if (dot(viewNormal, lightDir) > 0.0)
+    {
+        vec3 halfVec = normalize(lightDir - viewDir);
+        float NdotH = max(dot(viewNormal, halfVec), 0.0);
+        return pow(NdotH, shininess);
+    }
+
+    return 0.0;
+}
+
+vec3 getSpecular(vec3 viewNormal, vec3 viewPos, float shininess, float shadowing)
+{
+    shininess = max(shininess, 1e-4);
+    vec3 viewDir = normalize(viewPos);
+    vec3 specularLight = lcalcSpecular(0).xyz * calcSpecIntensity(viewNormal, viewDir, shininess, normalize(lcalcPosition(0)));
+    specularLight *= shadowing;
+
+    for (int i = @startLight; i < @endLight; ++i)
+    {
+#if @lightingMethodUBO
+        int lightIndex = PointLightIndex[i];
+#else
+        int lightIndex = i;
+#endif
+
+        vec3 lightPos = lcalcPosition(lightIndex) - viewPos;
+        float lightDistance = length(lightPos);
+
+#if !@lightingMethodFFP
+        if (lightDistance > lcalcRadius(lightIndex) * 2.0)
+            continue;
+#endif
+
+        float illumination = lcalcIllumination(lightIndex, lightDistance);
+        float intensity = calcSpecIntensity(viewNormal, viewDir, shininess, normalize(lightPos));
+        specularLight += lcalcSpecular(lightIndex).xyz * intensity * illumination;
+    }
+
+    return specularLight;
 }
 
 #endif