[Bf-docboard-svn] bf-manual: [9486] branches/blender-3.3-release/blender_docs/manual/modeling/meshes/uv/tools/relax.rst: Update Relax Brush documentation

[Aaron Carlisle]

Revision: 9486
          https://developer.blender.org/rBM9486
Author:   Blendify
Date:     2022-08-17 23:32:02 +0200 (Wed, 17 Aug 2022)
Log Message:
-----------
Update Relax Brush documentation

Author: @chrisbblend

Differential Revision: https://developer.blender.org/D15609

Modified Paths:
--------------
    branches/blender-3.3-release/blender_docs/manual/modeling/meshes/uv/tools/relax.rst

Modified: branches/blender-3.3-release/blender_docs/manual/modeling/meshes/uv/tools/relax.rst
===================================================================
--- branches/blender-3.3-release/blender_docs/manual/modeling/meshes/uv/tools/relax.rst	2022-08-16 02:20:14 UTC (rev 9485)
+++ branches/blender-3.3-release/blender_docs/manual/modeling/meshes/uv/tools/relax.rst	2022-08-17 21:32:02 UTC (rev 9486)
@@ -8,16 +8,16 @@
    :Mode:      Edit Mode
    :Tool:      :menuselection:`Toolbar --> Relax`
 
-The Relax brush makes UVs more evenly distributed.
-The algorithm relies on space, not stretch minimization,
-so most probably a minimize stretch will have to be run for optimal results.
-However, it is great to use after stitching islands
-or when unwrap produces cluttered results to smooth the distribution of UVs.
+The Relax brush can be used to distribute UVs more evenly.
+It works by pulling vertices along UV edges to bring the UV unwrap into balance.
 
-Relaxation Method
-   There are two relax algorithms:
+The Relax brush can be compared with the :ref:`minimize-stretch` tool which works directly
+on faces to reduce texture stretching and shearing.
+You may find that sometimes minimize stretch works better, sometimes the unwrap
+tool and other times the relax brush.
 
-   Laplacian, HC
+First using Unwrap, then Minimize Stretch and touching up with the Relax Brush often gives the best results.
+Remember, you can use "Undo" at any time to return to an earlier state.
 
 
 Tool Settings
@@ -53,11 +53,26 @@
    Use Unified Strength
       Use the same brush *Strength* across all brushes.
 
+.. _bpy.types.ToolSettings.uv_relax_method:
+
 Relaxation Method
-   There are two relax algorithms:
+   There are three ways to determine the edge weighting:
 
-   Laplacian, HC
+   :Laplacian:
+     The classic discrete laplace operator applied to the UV graph. Each edge has equal weighting,
+     resulting in triangles which resemble a honeycomb shape, or quads aligned into square grid.
+   :HC:
+     Similar to Laplacian, the HC method uses equal weighting while trying to preserve
+     a gradient between dense regions of the mesh and regions with fewer edges.e
 
+     Note, this method uses the The "Humphrey's Classes" operator as described in the paper:
+     `"Improved Laplacian Smoothing of Noisy Surface Meshes"
+     <http://informatikbuero.com/downloads/Improved_Laplacian_Smoothing_of_Noisy_Surface_Meshes.pdf>`
+   :Geometry:
+     Edges are weighted according to the discrete laplace operator (cotangent formula) applied to the 3D geometry.
+     This tries to bring the relative lengths of edges in UV closer to the relative lengths of edges in 3D,
+     resulting in a UV unwrap with less distortion across edge boundaries.
+
 .. note::
 
    All brushes use the :doc:`Airbrush Stroke Method </sculpt_paint/brush/stroke>`;
@@ -83,7 +98,7 @@
 
 Lock Borders
    Locks the boundary of UV islands from being affected by the brush.
-   This is very useful to preserve the shape of UV islands.
+   This is useful to preserve the shape of UV islands.
 Sculpt All Islands
    To edit all islands and not only the island nearest to the brush center
    when the sculpt stroke was started.