manual/render/eevee/world_settings.rst

@@ -1,13 +1,12 @@
 
-*****
-World
-*****
+**************
+World Settings
+**************
 
 The world environment can emit light, ranging from a single solid color
 to arbitrary textures.
 
-In EEVEE, the world lighting contribution is first rendered and
-stored in smaller resolution textures before being applied to the objects.
+In EEVEE, the world lighting contribution is stored into internal :ref:`Light Probe`.
 This makes the lighting less precise than Cycles.
 
 Mist Pass
@@ -17,27 +16,92 @@ Mist Pass
 
    :Panel:     :menuselection:`World --> Mist Pass`
 
+.. note::
+
+   The mist pass must be enabled in the View Layer tab
+   of the :doc:`Properties Editor </editors/properties_editor>`
+   before the settings below are available in the World tab.
+
+Mist can greatly enhance the illusion of depth in your rendering. To create mist,
+Blender generates a render layer with a depth map ranging between 0.0 and 1.0
+that can be used in the Compositor to generate a mist effect.
+
+.. _bpy.types.WorldMistSettings.start:
+
 Start
-   Starting distance of the mist, measured from the camera.
+   The distance from the camera at which the mist starts to fade in.
+
+.. _bpy.types.WorldMistSettings.depth:
 
 Depth
-   Distance over which the mist effect fades in.
+   The distance from *Start* of the mist, that it fades in over.
+   Objects further from the camera than *Start + Depth* are completely hidden by the mist.
+
+.. _bpy.types.WorldMistSettings.falloff:
 
 Falloff
-   Type of transition used to face mist.
+   The curve function that controls the rate of change of the mist's strength further and further into the distance.
+
+   :Quadratic:
+      Uses the same calculation as light falloff (:math:`1\over{x^2}`) and provides the smoothest
+      transition from transparent (0.0) to opaque (1.0).
+   :Linear: Has a steeper start than quadratic (:math:`1\over{x}`).
+   :Inverse Quadratic:
+      Has the steepest start (:math:`1\over{\sqrt{x}}`) and approaches 1.0 faster than the other two functions.
+
+.. tip::
+
+   A visualization can be activated in the :menuselection:`Camera --> Viewport Display` panel.
+
+.. figure:: /images/render_cycles_world-settings_mist-example1-BI.jpg
+
+   Mist example
+   (`blend-file <https://archive.blender.org/wiki/2015/index.php/File:25-Manual-World-Mist-Example1.blend>`__).
 
 
-Light Probe
-===========
+Settings
+========
 
 .. reference::
 
    :Panel:     :menuselection:`World --> Light Probe`
 
+
+Light Probe
+-----------
+
+.. _bpy.types.World.probe_resolution:
+
 Resolution
    The resolution used to store the light from the world.
-
+   This is equivalent to the resolution for light probe spheres.
 
 .. seealso::
 
-   :doc:`Indirect Lighting </render/eevee/render_settings/light_probes>`.
+   :doc:`Light Probe Sphere </render/eevee/light_probes/sphere>`.
+
+Sun
+---
+
+EEVEE can separate the light from intense light sources (e.g. a sun from an outdoor HDRI) and
+replace them by a sun light. This increases the quality of the lighting as the internal light probes
+alone cannot reproduce this type of lighting with enough precision.
+
+Threshold
+   If non-zero, the maximum value for world contribution that will be recorded inside the world light probe.
+   The excess contribution is converted to a sun light.
+   This reduces the light bleeding caused by very bright light sources.
+   A value of zero will disable this feature and all lighting will be stored inside the internal light probes.
+
+Angle
+   Angle of the extracted sun light.
+   Angular diameter of the Sun as seen from the Earth
+
+Use Shadow
+   Enable shadow casting on the extracted sun light.
+
+.. seealso::
+
+   The shadow properties control the extracted sun shadows.
+   They are exactly the same as for a sun light object.
+   :doc:`Light Properties </render/eevee/light_settings>`.