addressed some more PR edit requests, mostly clarification;

bumped ghoul to match current master

data/assets/examples/celestial_globe.asset

@@ -14,7 +14,9 @@ local celestial_globe_folder = asset.resource({
   Version = 1
 })
 
-local ModelMars1 = {
+-- These models are in the same shadow group, so will cast onto and receive
+--  shadows from each other, as well as the Mars surface
+local ModelMarsSmall = {
   Identifier = "celestial-globe-mars1",
   Parent = mars.Mars.Identifier,
   Transform = {
@@ -52,7 +54,7 @@ local ModelMars1 = {
   }
 }
 
-local ModelMars2 = {
+local ModelMarsLarge = {
   Identifier = "celestial-globe-mars2",
   Parent = mars.Mars.Identifier,
   Transform = {
@@ -94,7 +96,8 @@ local ModelMars2 = {
   }
 }
 
-local ModelMars3 = {
+-- This model is in a different shadow group, so will not receive or cast shadows onto the other Mars models
+local ModelMarsOtherGroup = {
   Identifier = "celestial-globe-mars3",
   Parent = mars.Mars.Identifier,
   Transform = {
@@ -136,6 +139,7 @@ local ModelMars3 = {
   }
 }
 
+-- Models that are far away MUST have their own shadow groups, otherwise no shadows will be visible
 local ModelEarth = {
   Identifier = "celestial-globe-earth",
   Parent = earth.Earth.Identifier,
@@ -214,9 +218,9 @@ local ModelMoon = {
 
 
 asset.onInitialize(function()
-  openspace.addSceneGraphNode(ModelMars1)
-  openspace.addSceneGraphNode(ModelMars2)
-  openspace.addSceneGraphNode(ModelMars3)
+  openspace.addSceneGraphNode(ModelMarsSmall)
+  openspace.addSceneGraphNode(ModelMarsLarge)
+  openspace.addSceneGraphNode(ModelMarsOtherGroup)
   openspace.addSceneGraphNode(ModelEarth)
   openspace.addSceneGraphNode(ModelMoon)
 end)
@@ -224,7 +228,7 @@ end)
 asset.onDeinitialize(function()
   openspace.removeSceneGraphNode(ModelMoon)
   openspace.removeSceneGraphNode(ModelEarth)
-  openspace.removeSceneGraphNode(ModelMars3)
-  openspace.removeSceneGraphNode(ModelMars2)
-  openspace.removeSceneGraphNode(ModelMars1)
+  openspace.removeSceneGraphNode(ModelMarsOtherGroup)
+  openspace.removeSceneGraphNode(ModelMarsLarge)
+  openspace.removeSceneGraphNode(ModelMarsSmall)
 end)

data/profiles/shadows_test.profile

@@ -26,6 +26,7 @@
     "celestial-globe-earth",
     "celestial-globe-mars1",
     "celestial-globe-mars2",
+    "celestial-globe-mars3",
     "celestial-globe-moon",
     "Earth",
     "Moon",

modules/base/shaders/model_fs.glsl

@@ -183,18 +183,20 @@ Fragment getFragment() {
     if (has_shadow_depth_map) {
       const float bias = 0.0005;
       vec3 coords = 0.5 + 0.5 * lightspace_position.xyz / lightspace_position.w;
-      vec2 ssz = 1.f / textureSize(shadow_depth_map, 0);
-      const int sz = 3;
-      const float norm = pow(2.f * sz + 1, 2.f);
-      float accum = 0.f;
 
-      for (int x = -sz; x <= sz; ++x) {
-        for (int y = -sz; y <= sz; ++y) {
-          float depth = texture(shadow_depth_map, coords.xy + vec2(x * ssz.x, y * ssz.y)).r;
+      // Any fragment that is behind the stored depth is in shadow, multisampling for smoother shadows
+      const int shadowFilterSize = 3;
+      float accum = 0.f;
+      vec2 stepSize = 1.f / textureSize(shadow_depth_map, 0);
+      for (int x = -shadowFilterSize; x <= shadowFilterSize; ++x) {
+        for (int y = -shadowFilterSize; y <= shadowFilterSize; ++y) {
+          float depth = texture(shadow_depth_map, coords.xy + vec2(x * stepSize.x, y * stepSize.y)).r;
           accum += float(coords.z < 1.f && depth > coords.z - bias);
         }
       }
 
+      // Scale the accumulated shadow factor to [0, 1]
+      const float norm = pow(2.f * shadowFilterSize + 1, 2.f);
       float shadowFactor = accum / norm;
       // Apply shadow to diffuse lighting (with ambient contribution)
       vec3 ambientLightColor = ambientIntensity * lightColor * diffuseAlbedo.rgb;

modules/globebrowsing/src/renderableglobe.cpp

@@ -136,7 +136,7 @@ namespace {
     constexpr openspace::properties::Property::PropertyInfo PerformHorizonCullingInfo = {
         "PerformHorizonCulling",
         "Perform horizon culling",
-        "If this value is set to 'true', horizon culling will be performed.",
+        "If this value is set to 'true', renderables below the horizon will be culled.",
         openspace::properties::Property::Visibility::AdvancedUser
     };
 

src/rendering/framebufferrenderer.cpp

@@ -487,7 +487,7 @@ void FramebufferRenderer::registerShadowCaster(const std::string& shadowgroup,
 std::pair<GLuint, glm::dmat4> FramebufferRenderer::shadowInformation(
     const SceneGraphNode* node, const std::string& shadowgroup) const
 {
-    ghoul_assert(_shadowMaps.contains(shadowgroup), "");
+    ghoul_assert(_shadowMaps.contains(shadowgroup), "Shadow group not registered");
     return {
         _shadowMaps.at(shadowgroup).depthMap,
         _shadowMaps.at(shadowgroup).viewProjectionMatrix