improving on the poin light attenuatiion formula

libraries/model/src/model/Light.cpp

@@ -40,25 +40,19 @@ Light::~Light() {
 
 void Light::setPosition(const Vec3& position) {
     _transform.setTranslation(position);
-    _transform.getMatrix(editSchema()._transform);
+    editSchema()._position = Vec4(position, 1.f);
 }
 
 void Light::setOrientation(const glm::quat& orientation) {
     _transform.setRotation(orientation);
-    _transform.getMatrix(editSchema()._transform);
 }
 
 void Light::setDirection(const Vec3& direction) {
-    glm::mat3 rotation(
+    editSchema()._direction = Vec4(direction, 0.f);
-        Vec3(1.0f, 0.0f, 0.0f),
-        Vec3(0.0f, 1.0f, 0.0f),
-        -direction);
-
-    setOrientation(glm::quat(rotation));
 }
 
 const Vec3& Light::getDirection() const {
-    return Vec3(_transform.transform(Vec4(0.0f, 0.0f, 1.0f, 0.0f)));
+    return Vec3(getSchema()._direction);
 }
 
 void Light::setColor(const Color& color) {
@@ -69,11 +63,13 @@ void Light::setIntensity(float intensity) {
     editSchema()._intensity = intensity;
 }
 
-void Light::setAttenuationRadius(float radius) {
+void Light::setMaximumRadius(float radius) {
     if (radius <= 0.f) {
         radius = 1.0f;
     }
-    editSchema()._attenuation = Vec4(1.0f, 2.0f/radius, 1.0f/(radius*radius), radius);
+    float CutOffIntensityRatio = 0.01f;
+    float surfaceRadius = radius / (sqrt(1.0f / CutOffIntensityRatio) - 1.f);
+    editSchema()._attenuation = Vec4(surfaceRadius, 1.0f/surfaceRadius, CutOffIntensityRatio, radius);
 }
 
 void Light::setSpotCone(float angle) {

libraries/model/src/model/Light.h

@@ -74,8 +74,8 @@ public:
 
     bool isRanged() const { return (getType() == POINT) || (getType() == SPOT ); }
  
-    void setAttenuationRadius(float radius);
+    void setMaximumRadius(float radius);
-    float getAttenuationRadius() const { return getSchema()._attenuation.w; }
+    float getMaximumRadius() const { return getSchema()._attenuation.w; }
 
     // Spot properties
     bool isSpot() const { return getType() == SPOT; }
@@ -87,7 +87,8 @@ public:
     // Schema to access the attribute values of the light
     class Schema {
     public:
-        glm::mat4 _transform; 
+        Vec4 _position; 
+        Vec4 _direction;
         Color _color;
         float _intensity;
         Vec4 _attenuation;
@@ -97,10 +98,11 @@ public:
         Vec4 _control;
 
         Schema() :
-            _transform(),
+            _position(0.0f, 0.0f, 0.0f, 1.0f), 
+            _direction(0.0f, 0.0f, -1.0f, 0.f), 
             _color(1.0f),
             _intensity(1.0f),
-            _attenuation(1.0f, 2.0f, 1.0f, 1.0f),
+            _attenuation(1.0f, 1.0f, 1.0f, 1.0f),
             _spot(0.0f, 0.0f, 0.0f, 0.0f),
             _control(0.0f)
             {}

libraries/render-utils/src/DeferredLightingEffect.cpp

@@ -275,7 +275,7 @@ void DeferredLightingEffect::addSpotLight(const glm::vec3& position, float radiu
 
         model::LightPointer lp = model::LightPointer(new model::Light());
         lp->setPosition(position);
-        lp->setAttenuationRadius(radius);
+        lp->setMaximumRadius(radius);
         lp->setColor(diffuse);
         lp->setIntensity(1.0f);
         lp->setType(model::Light::POINT);
@@ -297,7 +297,7 @@ void DeferredLightingEffect::addSpotLight(const glm::vec3& position, float radiu
         model::LightPointer ls = model::LightPointer(new model::Light());
         ls->setPosition(position);
         ls->setDirection(direction);
-        ls->setAttenuationRadius(radius);
+        ls->setMaximumRadius(radius);
         ls->setSpotCone(cutoff);
         ls->setColor(diffuse);
         ls->setIntensity(1.0f);
@@ -453,6 +453,8 @@ void DeferredLightingEffect::render() {
     
     const glm::vec3& eyePoint = _viewState->getCurrentViewFrustum()->getPosition();
     float nearRadius = glm::distance(eyePoint, _viewState->getCurrentViewFrustum()->getNearTopLeft());
+    glm::mat4 invViewMat;
+    _viewState->getViewTransform().getMatrix(invViewMat);
 
     auto geometryCache = DependencyManager::get<GeometryCache>();
     
@@ -470,7 +472,9 @@ void DeferredLightingEffect::render() {
                 batch.setUniformBuffer(_pointLightLocations.lightBufferUnit, light->getSchemaBuffer());
                 gpu::GLBackend::renderBatch(batch);
             }
-            _spotLight.setUniformValue(_pointLightLocations.radius, light->getAttenuationRadius());
+            glUniformMatrix4fv(_pointLightLocations.invViewMat, 1, false, reinterpret_cast< const GLfloat* >(&invViewMat));
+           // _pointLight.setUniformValue(_pointLightLocations.viewMat, reinterpret_cast< const GLfloat* >(&viewMat));
+         //   _spotLight.setUniformValue(_pointLightLocations.radius, light->getAttenuationRadius());
             
 
 /*
@@ -485,7 +489,7 @@ void DeferredLightingEffect::render() {
          */
             glPushMatrix();
             
-            float expandedRadius = light->getAttenuationRadius() * (1.0f + SCALE_EXPANSION);
+            float expandedRadius = light->getMaximumRadius() * (1.0f + SCALE_EXPANSION);
             if (glm::distance(eyePoint, glm::vec3(light->getPosition())) < expandedRadius + nearRadius) {
                 glLoadIdentity();
                 glTranslatef(0.0f, 0.0f, -1.0f);
@@ -525,7 +529,7 @@ void DeferredLightingEffect::render() {
                 batch.setUniformBuffer(_spotLightLocations.lightBufferUnit, light->getSchemaBuffer());
                 gpu::GLBackend::renderBatch(batch);
             }
-            _spotLight.setUniformValue(_spotLightLocations.radius, light->getAttenuationRadius());
+     //       _spotLight.setUniformValue(_spotLightLocations.radius, light->getAttenuationRadius());
             
             /*
                       _spotLight.setUniformValue(_spotLightLocations.radius, light.radius);
@@ -543,7 +547,7 @@ void DeferredLightingEffect::render() {
 
             glPushMatrix();
             
-            float expandedRadius = light->getAttenuationRadius() * (1.0f + SCALE_EXPANSION);
+            float expandedRadius = light->getMaximumRadius() * (1.0f + SCALE_EXPANSION);
             float edgeRadius = expandedRadius / glm::cos(light->getSpotConeAngle());
             if (glm::distance(eyePoint, glm::vec3(light->getPosition())) < edgeRadius + nearRadius) {
                 glLoadIdentity();
@@ -563,7 +567,7 @@ void DeferredLightingEffect::render() {
                 glm::quat spotRotation = rotationBetween(glm::vec3(0.0f, 0.0f, -1.0f), light->getDirection());
                 glm::vec3 axis = glm::axis(spotRotation);
                 glRotatef(glm::degrees(glm::angle(spotRotation)), axis.x, axis.y, axis.z);   
-                glTranslatef(0.0f, 0.0f, -light->getAttenuationRadius() * (1.0f + SCALE_EXPANSION * 0.5f));  
+                glTranslatef(0.0f, 0.0f, -light->getMaximumRadius() * (1.0f + SCALE_EXPANSION * 0.5f));  
                 geometryCache->renderCone(expandedRadius * glm::tan(light->getSpotConeAngle()),
                     expandedRadius, 32, 1);
             }
@@ -649,6 +653,7 @@ void DeferredLightingEffect::loadLightProgram(const char* fragSource, bool limit
     locations.depthTexCoordScale = program.uniformLocation("depthTexCoordScale");
     locations.radius = program.uniformLocation("radius");
     locations.ambientSphere = program.uniformLocation("ambientSphere.L00");
+    locations.invViewMat = program.uniformLocation("invViewMat");
 
     GLint loc = -1;
 #if defined(Q_OS_MAC)
@@ -661,8 +666,8 @@ void DeferredLightingEffect::loadLightProgram(const char* fragSource, bool limit
 #elif defined(Q_OS_WIN)
     loc = glGetUniformBlockIndex(program.programId(), "lightBuffer");
     if (loc >= 0) {
-        glUniformBlockBinding(program.programId(), loc, 1);
+        glUniformBlockBinding(program.programId(), loc, 0);
-        locations.lightBufferUnit = 1;
+        locations.lightBufferUnit = 0;
     } else {
         locations.lightBufferUnit = -1;
     }

libraries/render-utils/src/DeferredLightingEffect.h

@@ -105,6 +105,7 @@ private:
         int radius;
         int ambientSphere;
         int lightBufferUnit;
+        int invViewMat;
     };
     
     static void loadLightProgram(const char* fragSource, bool limited, ProgramObject& program, LightLocations& locations);

libraries/render-utils/src/Light.slh

@@ -12,8 +12,8 @@
 <@def LIGHT_SLH@>
 
 struct Light {
-    mat4 _transform;
+    vec4 _position;
-
+    vec4 _direction;
     vec4 _color;
     vec4 _attenuation;
     vec4 _spot;
@@ -23,14 +23,18 @@ struct Light {
     vec4 _control;
 };
 
-vec3 getLightPosition(Light l) { return l._transform[3].xyz; }
+vec3 getLightPosition(Light l) { return l._position.xyz; }
-vec3 getLightDirection(Light l) { return -l._transform[2].xyz; } // direction is -Z axis
+vec3 getLightDirection(Light l) { return l._direction.xyz; } // direction is -Z axis
 
 vec3 getLightColor(Light l) { return l._color.rgb; }
 float getLightIntensity(Light l) { return l._color.w; }
 
 float evalLightAttenuation(Light l, float r) {
-    return clamp(1.0/(l._attenuation.x + l._attenuation.y * r + l._attenuation.z * r * r), 0.0, 1.0);
+    float d = max(r - l._attenuation.x, 0.0);
+    float denom = d * l._attenuation.y + 1.0;
+    float attenuation = 1.0 / (denom * denom);
+    return max((attenuation - l._attenuation.z)/(1.0 - l._attenuation.z), 0.0);
+  //  return clamp(1.0/(l._attenuation.x + l._attenuation.y * r + l._attenuation.z * r * r), 0.0, 1.0);
 }
 
 float evalLightSpotAttenuation(Light l, float cosA) {
@@ -40,6 +44,9 @@ float evalLightSpotAttenuation(Light l, float cosA) {
     return clamp(pow(cosA / l._spot.x, l._spot.w), 0.0, 1.0);
 }
 
+float getLightSquareRadius(Light l) {
+    return l._attenuation.w * l._attenuation.w;
+}
 
 
 <@if GLPROFILE == PC_GL@>

libraries/render-utils/src/point_light.slf

@@ -21,6 +21,8 @@
 // the radius (hard cutoff) of the light effect
 uniform float radius;
 
+uniform mat4 invViewMat;
+
 void main(void) {
     // get the depth and exit early if it doesn't pass the test
     vec2 texCoord = gl_TexCoord[0].st / gl_TexCoord[0].q;
@@ -32,18 +34,25 @@ void main(void) {
         discard;
     }
 
-    // compute the view space position using the depth
+    vec4 wPos;
-    float z = near / (depth * depthScale - 1.0);
+    wPos = invViewMat * frag.position;
-    vec4 position = vec4((depthTexCoordOffset + texCoord * depthTexCoordScale) * z, z, 1.0);
+    Light light = getLight();
+    gl_FragColor = vec4(frag.normal, 0.0);
 
-    // get the normal from the map
+    vec3 lightVector = getLightPosition(light) - wPos.xyz;
-    vec4 normal = texture2D(normalMap, texCoord);
+    if (dot(lightVector, lightVector) > getLightSquareRadius(light)) {
-    vec4 normalizedNormal = normalize(normal * 2.0 - vec4(1.0, 1.0, 1.0, 2.0));
+        discard;
+    }
 
-    // compute the base color based on OpenGL lighting model
-    vec4 lightVector = gl_LightSource[1].position - position;
     float lightDistance = length(lightVector);
     lightVector = lightVector / lightDistance;
+
+    float lightAttenuation = evalLightAttenuation(light, lightDistance);
+    gl_FragColor.xyz *= lightAttenuation;
+/*
+    float diffuse = dot(frag.normal, lightVector);
+
+ 
     float diffuse = dot(normalizedNormal, lightVector);
     float facingLight = step(0.0, diffuse);
     vec4 baseColor = texture2D(diffuseMap, texCoord) * (gl_FrontLightProduct[1].ambient +
@@ -59,6 +68,6 @@ void main(void) {
         normalizedNormal));    
     vec4 specularColor = texture2D(specularMap, texCoord);
     gl_FragColor = vec4((baseColor.rgb + pow(specular, specularColor.a * 128.0) * specularColor.rgb) * attenuation, 0.0);
-
+    */
-    gl_FragColor = vec4(frag.normal, 0.0);
+  //  gl_FragColor = vec4(frag.normal, 0.0);
 }