Basic fast filtering implementation

3 files changed, 17 insertions, 8 deletions

diff --git a/doc/classes/ProjectSettings.xml b/doc/classes/ProjectSettings.xml
index 679a462d65..a2c6ed34e0 100644
--- a/doc/classes/ProjectSettings.xml
+++ b/doc/classes/ProjectSettings.xml
@@ -1037,23 +1037,28 @@
 			Lower-end override for [member rendering/quality/intended_usage/framebuffer_allocation] on mobile devices, due to performance concerns or driver support.
 		</member>
 		<member name="rendering/quality/reflection_atlas/reflection_count" type="int" setter="" getter="" default="64">
+			Number of cubemaps to store in the reflection atlas. The number of [ReflectionProbe]s in a scene will be limited by this amount. A higher number requires more VRAM.
 		</member>
-		<member name="rendering/quality/reflection_atlas/reflection_size" type="int" setter="" getter="" default="256">
+		<member name="rendering/quality/reflection_atlas/reflection_size" type="int" setter="" getter="" default="128">
+			Size of cubemap faces for [ReflectionProbe]s. A higher number requires more VRAM and may make reflection probe updating slower.
 		</member>
 		<member name="rendering/quality/reflection_atlas/reflection_size.mobile" type="int" setter="" getter="" default="128">
+			Lower-end override for [member rendering/quality/reflection_atlas/reflection_size] on mobile devices, due to performance concerns or driver support.
+		</member>
+		<member name="rendering/quality/reflections/fast_filter_high_quality" type="bool" setter="" getter="" default="false">
+			Use a higher quality variant of the fast filtering algorithm. Significantly slower than using default quality, but results in smoother reflections. Should only be used when the scene is especially detailed.
 		</member>
 		<member name="rendering/quality/reflections/ggx_samples" type="int" setter="" getter="" default="1024">
+			Sets the number of samples to take when using importance sampling for [Sky]s and [ReflectionProbe]s. A higher value will result in smoother, higher quality reflections, but increases time to calculate radiance maps. In general, fewer samples are needed for simpler, low dynamic range environments while more samples are needed for HDR environments and environments with a high level of detail.
 		</member>
 		<member name="rendering/quality/reflections/ggx_samples.mobile" type="int" setter="" getter="" default="128">
-		</member>
-		<member name="rendering/quality/reflections/ggx_samples_realtime" type="int" setter="" getter="" default="64">
-		</member>
-		<member name="rendering/quality/reflections/ggx_samples_realtime.mobile" type="int" setter="" getter="" default="16">
+			Lower-end override for [member rendering/quality/reflections/ggx_samples] on mobile devices, due to performance concerns or driver support.
 		</member>
 		<member name="rendering/quality/reflections/roughness_layers" type="int" setter="" getter="" default="6">
+			Limits the number of layers to use in radiance maps when using importance sampling. A lower number will be slightly faster and take up less VRAM.
 		</member>
 		<member name="rendering/quality/reflections/texture_array_reflections" type="bool" setter="" getter="" default="true">
-			If [code]true[/code], uses texture arrays instead of mipmaps for reflection probes and panorama backgrounds (sky). This reduces jitter noise on reflections, but costs more performance and memory.
+			If [code]true[/code], uses texture arrays instead of mipmaps for reflection probes and panorama backgrounds (sky). This reduces jitter noise and upscaling artifacts on reflections, but is significantly slower to compute and uses [member rendering/quality/reflections/roughness_layers] times more memory.
 		</member>
 		<member name="rendering/quality/reflections/texture_array_reflections.mobile" type="bool" setter="" getter="" default="false">
 			Lower-end override for [member rendering/quality/reflections/texture_array_reflections] on mobile devices, due to performance concerns or driver support.
diff --git a/doc/classes/ReflectionProbe.xml b/doc/classes/ReflectionProbe.xml
index 9c7a645fec..e138af6841 100644
--- a/doc/classes/ReflectionProbe.xml
+++ b/doc/classes/ReflectionProbe.xml
@@ -4,7 +4,7 @@
 		Captures its surroundings to create reflections.
 	</brief_description>
 	<description>
-		Capture its surroundings as a dual parabolid image, and stores versions of it with increasing levels of blur to simulate different material roughnesses.
+		Captures its surroundings as a cubemap, and stores versions of it with increasing levels of blur to simulate different material roughnesses.
 		The [ReflectionProbe] is used to create high-quality reflections at the cost of performance. It can be combined with [GIProbe]s and Screen Space Reflections to achieve high quality reflections. [ReflectionProbe]s render all objects within their [member cull_mask], so updating them can be quite expensive. It is best to update them once with the important static objects and then leave them.
 	</description>
 	<tutorials>
@@ -52,7 +52,7 @@
 	</members>
 	<constants>
 		<constant name="UPDATE_ONCE" value="0" enum="UpdateMode">
-			Update the probe once on the next frame.
+			Update the probe once on the next frame. The corresponding radiance map will be generated over the following six frames. This is slower to update than [constant UPDATE_ALWAYS] but can result in higher quality reflections.
 		</constant>
 		<constant name="UPDATE_ALWAYS" value="1" enum="UpdateMode">
 			Update the probe every frame. This is needed when you want to capture dynamic objects. However, it results in an increased render time. Use [constant UPDATE_ONCE] whenever possible.
diff --git a/doc/classes/Sky.xml b/doc/classes/Sky.xml
index 72599a323d..ba9c5ee661 100644
--- a/doc/classes/Sky.xml
+++ b/doc/classes/Sky.xml
@@ -12,6 +12,7 @@
 	</methods>
 	<members>
 		<member name="process_mode" type="int" setter="set_process_mode" getter="get_process_mode" enum="Sky.ProcessMode" default="0">
+			Sets the method for generating the radiance map from the sky. The radiance map is a cubemap with increasingly blurry versions of the sky corresponding to different levels of roughness. Radiance maps can be expensive to calculate. See [enum ProcessMode] for options.
 		</member>
 		<member name="radiance_size" type="int" setter="set_radiance_size" getter="get_radiance_size" enum="Sky.RadianceSize" default="2">
 			The [Sky]'s radiance map size. The higher the radiance map size, the more detailed the lighting from the [Sky] will be.
@@ -45,8 +46,11 @@
 			Represents the size of the [enum RadianceSize] enum.
 		</constant>
 		<constant name="PROCESS_MODE_QUALITY" value="0" enum="ProcessMode">
+			Uses high quality importance sampling to process the radiance map. In general, this results in much higher quality than [constant PROCESS_MODE_REALTIME] but takes much longer to generate. This should not be used if you plan on changing the sky at runtime.
 		</constant>
 		<constant name="PROCESS_MODE_REALTIME" value="1" enum="ProcessMode">
+			Uses the fast filtering algorithm to process the radiance map. In general this results in lower quality, but substantially faster run times.
+			[b]Note:[/b] The fast filtering algorithm is limited to 128x128 cubemaps, so [member radiance_size] must be set to [constant RADIANCE_SIZE_128].
 		</constant>
 	</constants>
 </class>