3DCoatScripting  4.8.31β
You can manage 3DСoat features with help of scripting
🌀 2D layers for painting

In Paint Room you may from script:

// add new layer for painting
void AddPaintLayer( string );
// get current layer's name
string GetCurrentPaintLayerName();
// rename current layer
void RenameCurrentPaintLayer( string );
// select layer by its name
bool SelectPaintLayer( string )
// select bottom layer
void SelectFirstPaintLayer( bool )
// select next layer
bool SelectNextPaintLayer( bool )
// get layer visibility (true/false)
bool GetPaintLayerVisibility()
// make layer visible (`true`) or invisible (`false`)
void SetPaintLayerVisibility( bool )
// set layer's opacity (`0 .. 100`)
void SetPaintLayerOpacity( float )
// set layer's depth channel opacity (`0 .. 100`)
void SetPaintLayerDepthOpacity( float )

Check this set of functions for fuller understanding:

// Returns whole command line.
string getCommandLine();
// Stores some string as global value that may be read later in
// the session. The value will be stored in 3B file and you will
// be able to read in further work with this scene.
DEPRECATED void SetGlobalVar(string& Name,string& Value)
// Returns value previously stored using SetGlobalVar.
DEPRECATED string GetGlobalVar (string& Name)
// Returns scene filename (last saved or opened as 3B file).
DEPRECATED string GetSceneFileName()
// Sets scene filename for further saving.
DEPRECATED void SetSceneFileName(string& Name)
// Highlight element with red rectangle.
// Pass the `time` in seconds.
void HighlightUIElement(string &ID, float time);
// Goes to one of previous dialogs in call stack.
DEPRECATED void back(int steps=1);
// Opens window described by xml-file pointed by Path.
// If Path contains .3b file will be opened as 3B file.
DEPRECATED void open(string &Path);
// Opens model for PPP, if path is empty, shows open dialog.
DEPRECATED void ppp(string &path);
// Opens model for MV painting, if path is empty, shows open dialog.
DEPRECATED void mv(string &path);
// Opens model for Ptex, if path is empty, shows open dialog.
DEPRECATED void ptex(string &path);
// Import image as mesh, dialog will be shown.
DEPRECATED void imagemesh();
// Import mesh as reference, if path is empty dialog will be shown.
DEPRECATED void refmesh(string &path);
// Import mesh for vertex painting, if path is empty dialog will be shown.
DEPRECATED void vertexpaint(string &path);
// Perform autopo over the mesh chosen in dialog.
DEPRECATED void autopo(string &path);
// Opens mesh for repairing. If id contains "vox" then model will be
// voxelized, if there is substring "shell" then mesh will be imported
// as thin shell. Mesh Opening dialog will be shown.
DEPRECATED void repair(string &id);
// Activate bas-relief tool.
DEPRECATED void bass();
// Activale remove undercuts mode.
DEPRECATED void undercut();
// Activate special voxel tool. id may be found in English.xml between
// <ID>...</ID> if you will find name of tool between
// <Text>...</Text> tags.
DEPRECATED void activate(string &id);
// Activate retopo tool.
DEPRECATED void retopo();
// Open mesh using dialog and merge as retopo mesh.
DEPRECATED void retopopen();
// Activate any room - name is one of "Paint", "Tweak", "UV",
// "Voxels", "Retopo", "Render".
DEPRECATED void ToRoom(string &name);
// Check if you are in specified room - name is one of "Paint",
// "Tweak", "UV", "Voxels", "Retopo", "Render".
DEPRECATED bool IsInRoom(string &name);
// Add new volume in voxel room. If name is empty name will be
// assigned automatically.
DEPRECATED void AddNewVolume(string &name);
// Activate UV room.
DEPRECATED void uv();
// Activate voxel room and add new volume.
DEPRECATED void vox();
// Create sphere of radius R in voxel room in current object.
// \param mode 0 - add, 1 - subtract, 2 - intersect with scene.
DEPRECATED void sphere(float x,float y,float z,float r,int mode);
// Create cube in voxel room in current object.
// \param mode 0 - add, 1 - subtract, 2 - intersect with scene.
// \param sizex Size by X-axis.
// \param sizey Size by Y-axis.
// \param sizez Size by Z-axis.
DEPRECATED void cube(float x,float y,float z,float sizex,float sizey,float sizez,int mode);
// Turn all volumes to surface mode.
DEPRECATED void surf();
// Turn current volume to the surface mode.
DEPRECATED void cursurf();
// Turn current volume to voxel mode, voxelize if need.
DEPRECATED void voxelize();
// Sets merging options in voxel room. opt is just set of substrings
// with different options. Possible values are:
// [voxelize=true]
// [voxelize=false]
// [separate=true]
// [separate=false]
// [respectneg=true]
// [respectneg=false]
// [as_skin=true]
// [as_skin=false]
// [skin=....] - to set skin thickness.
DEPRECATED void mergeopt(string &opt);
// Example:
mergeopt( "[voxelize=true][as_skin=true][skin=4.5]" );
// Merge model in voxel room. Empty string means that dialog will be shown.
DEPRECATED void merge(string &model);
// Activate voxel primitives tool. Possible primitives:
// cube, cylinder, sphere, tube, cone, ellipse, n-gon, gear.
DEPRECATED void prim(string &id);
// Apply in current tool (same as press enter).
DEPRECATED void apply();
// Apply in Merge tool without asking "Keep scale?".
// Scale will not be kept and scene scale will not be changed.
DEPRECATED void ApplyAndKeepScale();
// Apply in current tool (same as press enter) wint one difference -
// in Merge tool scale of merged object sill be automatically kept and
// scene scale changed if this merge is first.
DEPRECATED void mapply();
// Open recent 3B-file.
DEPRECATED void recent3b();
// Print text to MyDocuments/3D-CoatV4/log.txt.
DEPRECATED void Log(string &line);
// Generate integer random number min..max.
int rand(int min,int max);
// Generate floating random number min..max.
float randF(float min,float max);
// Set random generator seed.
void seed(int val);
// Show progress bar pos = 0..100.
DEPRECATED void ProgressBar(const string& message,int pos);
// Set orthogonal (true) or perspective (false) view mode.
DEPRECATED void SetOrthoMode(bool value);