Rename 'transparency' to 'colorFilter' in the ring classes

to avoid confusion with opacity name change. Also, the 'transparency'
used in the rings had a diffrent meaning than for the rest of the
rendered objects. It affects the filtering of the color values.

modules/globebrowsing/shaders/rings_fs.glsl

@@ -35,7 +35,7 @@ in vec4 shadowCoords;
 uniform sampler2DShadow shadowMapTexture;
 uniform sampler1D ringTexture;
 uniform vec2 textureOffset;
-uniform float transparency;
+uniform float colorFilterValue;
 
 uniform vec3 sunPosition;
 uniform float _nightFactor;
@@ -67,12 +67,11 @@ Fragment getFragment() {
     }
 
     vec4 diffuse = texture(ringTexture, texCoord);
-    float colorValue = length(diffuse.rgb);
-    // times 3 as length of vec3(1.0, 1.0, 1.0) will return 3 and we want
-    // to normalize the transparency value to [0,1]
-    if (colorValue < 3.0 * transparency) {
-        diffuse.a = pow(colorValue / (3.0 * transparency), 1);
-        //diffuse.a = (colorValue / 3.0) * transparency;
+    // divided by 3 as length of vec3(1.0, 1.0, 1.0) will return 3 and we want
+    // to normalize the alpha value to [0,1]
+    float colorValue = length(diffuse.rgb) / 3.0;
+    if (colorValue < colorFilterValue) {
+        diffuse.a = colorValue * colorFilterValue;
         if (diffuse.a < 0.65)
             discard;
     }

modules/globebrowsing/src/ringscomponent.cpp

@@ -52,7 +52,7 @@ namespace {
     constexpr const char* _loggerCat = "RingsComponent";
 
     constexpr const std::array<const char*, 9> UniformNames = {
-        "modelViewProjectionMatrix", "textureOffset", "transparency", "_nightFactor",
+        "modelViewProjectionMatrix", "textureOffset", "colorFilterValue", "_nightFactor",
         "sunPosition", "ringTexture", "shadowMatrix", "shadowMapTexture",
         "zFightingPercentage"
     };
@@ -91,11 +91,11 @@ namespace {
         "of the night side occurs."
     };
 
-    constexpr openspace::properties::Property::PropertyInfo TransparencyInfo = {
-        "Transparency",
-        "Transparency",
-        "This value determines the transparency of part of the rings depending on the "
-        "color values. For this value v, the transparency is equal to length(color) / v."
+    constexpr openspace::properties::Property::PropertyInfo ColorFilterInfo = {
+        "ColorFilter",
+        "Color Filter",
+        "This value affects the filtering out of part of the rings depending on the "
+        "color values of the texture. The higher value, the more rings are filtered out."
     };
 
     constexpr openspace::properties::Property::PropertyInfo ZFightingPercentageInfo = {
@@ -146,10 +146,10 @@ documentation::Documentation RingsComponent::Documentation() {
                 NightFactorInfo.description
             },
             {
-                TransparencyInfo.identifier,
+                ColorFilterInfo.identifier,
                 new DoubleVerifier,
                 Optional::Yes,
-                TransparencyInfo.description
+                ColorFilterInfo.description
             },
             {
                 ZFightingPercentageInfo.identifier,
@@ -173,7 +173,7 @@ RingsComponent::RingsComponent(const ghoul::Dictionary& dictionary)
     , _size(SizeInfo, 1.f, 0.f, 1e25f)
     , _offset(OffsetInfo, glm::vec2(0.f, 1.f), glm::vec2(0.f), glm::vec2(1.f))
     , _nightFactor(NightFactorInfo, 0.33f, 0.f, 1.f)
-    , _transparency(TransparencyInfo, 0.15f, 0.f, 1.f)
+    , _colorFilter(ColorFilterInfo, 0.15f, 0.f, 1.f)
     , _enabled({ "Enabled", "Enabled", "Enable/Disable Rings" }, true)
     , _zFightingPercentage(ZFightingPercentageInfo, 0.995f, 0.000001f, 1.f)
     , _nShadowSamples(NumberShadowSamplesInfo, 2, 1, 7)
@@ -228,9 +228,9 @@ void RingsComponent::initialize() {
     }
     addProperty(_nightFactor);
 
-    if (_ringsDictionary.hasKeyAndValue<double>(TransparencyInfo.identifier)) {
-        _transparency = static_cast<float>(
-            _ringsDictionary.value<double>(TransparencyInfo.identifier)
+    if (_ringsDictionary.hasKeyAndValue<double>(ColorFilterInfo.identifier)) {
+        _colorFilter = static_cast<float>(
+            _ringsDictionary.value<double>(ColorFilterInfo.identifier)
         );
     }
 
@@ -248,7 +248,7 @@ void RingsComponent::initialize() {
     _nShadowSamples.onChange([this]() { compileShadowShader(); });
     addProperty(_nShadowSamples);
 
-    addProperty(_transparency);
+    addProperty(_colorFilter);
 }
 
 bool RingsComponent::isReady() const {
@@ -327,7 +327,7 @@ void RingsComponent::draw(const RenderData& data,
             modelViewProjectionTransform
         );
         _shader->setUniform(_uniformCache.textureOffset, _offset);
-        _shader->setUniform(_uniformCache.transparency, _transparency);
+        _shader->setUniform(_uniformCache.colorFilterValue, _colorFilter);
         _shader->setUniform(_uniformCache.nightFactor, _nightFactor);
         _shader->setUniform(_uniformCache.sunPosition, _sunPosition);
         _shader->setUniform(_uniformCache.zFightingPercentage, _zFightingPercentage);

modules/globebrowsing/src/ringscomponent.h

@@ -81,14 +81,14 @@ private:
     properties::FloatProperty _size;
     properties::Vec2Property _offset;
     properties::FloatProperty _nightFactor;
-    properties::FloatProperty _transparency;
+    properties::FloatProperty _colorFilter;
     properties::BoolProperty _enabled;
     properties::FloatProperty _zFightingPercentage;
     properties::IntProperty _nShadowSamples;
 
     std::unique_ptr<ghoul::opengl::ProgramObject> _shader;
     std::unique_ptr<ghoul::opengl::ProgramObject> _geometryOnlyShader;
-    UniformCache(modelViewProjectionMatrix, textureOffset, transparency, nightFactor,
+    UniformCache(modelViewProjectionMatrix, textureOffset, colorFilterValue, nightFactor,
         sunPosition, ringTexture, shadowMatrix, shadowMapTexture, zFightingPercentage
     ) _uniformCache;
     UniformCache(modelViewProjectionMatrix, textureOffset, ringTexture