Add documentation for functions to the readme

README.md

@@ -1,3 +1,76 @@
 # MeshTools
 
-This plugin adds several tools for analysis and manipulation of meshes
+This plugin adds several tools for analysis and manipulation of meshes.
+
+The following functions are available through both the `Extensions -> Mesh
+Tools` menu and the Mesh Tools submenu of the viewport context menu. These
+fuctions require one or more models being selected first.
+
+### Reload model
+Reloads the selected model(s) from disk, if the filename is known and the
+file still exists.
+
+### Rename model
+Changes the name of the model in the "Object List" in the lower left corner
+of the viewport. This currently does not work on groups.
+
+### Replace model
+Replaces the selected model(s) with a different file. This does not work on
+groups, and a single model can only be replaced with a single mesh.
+
+### Check mesh
+Checks to see if the model is "watertight", and if it contains separate 
+"submodels".
+
+### Analyse mesh
+Count the number of vertices and faces of the selected models.
+
+### Fix simple holes
+Try to fix simple holes in models to make them "watertight". This is not meant
+as an exhaustive way to repair all models. External tools may be necessary to
+repair extensively broken models.
+
+### Fix model normals
+Recalculate the model normals, so the visualisation of what parts of the model
+need support is accurate for models with reversed or invalid normals.
+
+### Split model into parts
+When multiple separate bodies are contained within a single mesh, this function
+can split them apart so they can be manipulated individually.
+
+### Randomise location
+When printing with a consumable build plate surface, it can be beneficial to
+print have each print on a different location on the build plate to make sure
+it wears down evenly.
+
+### Apply transformations to mesh
+This function applies the rotation and scale to the mesh coordinates, and
+resets the model rotation and scale to upright and 100%. This can make it
+easier to apply scale, and can prevent some manipulation inconsistencies in
+Cura (such as the wrong axis scaling when a model is rotated).
+
+### Reset origin to center of mesh
+When loading single models into Cura, the origin (the point around which the
+model is rotated) is normally reset to the center of the model. Some models
+may get a different origin, such as the resulting meshes from the "Split model
+into parts" function. It can be convenient to reset the origin to the center
+of these parts for further manipulation, but this will make Cura forget about
+the original relative position of parts so the "merge" function will no longer
+put the parts together properly.
+
+The following options can be set in the settings dialog which can be found via
+`Extensions -> Mesh Tools -> Mesh Tools Settings`:
+
+### Check models on load
+Automatically check the check models when loading them. In Cura 4.6 and newer
+this may lead to double messages that the model needs repair.
+
+### Fix normals on load
+Automatically recreate the normals for each loaded model. This can be useful
+if you use a modeler that uses a different normal "winding" than Cura, which
+causes Cura to show overhangs are needed on top of models.
+
+### Unit for files that don't specify a unit
+Automatically scale models that are loaded into Cura if they are exported in
+another unit than millimeters. This applies only to mesh files that do not
+specify the unit, such as STL, OBJ and PLY.