Photoshop script to export textures from layered PSD

ExportPBRTextures.jsx

// Enables exporting of several PBR maps from a single PSD with a few clicks:
// 1. Select an export folder (default to PSD path on Windows)
// 2. Choose which PSD layer group corresponds to which map (split into separate RGB/Alpha channels)
// 3. Change the file export options (if required)
// 4. Hit export.

#target photoshop
app.bringToFront();

// DEFAULT EXPORT OPTIONS
var options = {
	autoSave: true,
	lowercaseFilename: true,
	removeFilenameSpaces: true,
	closeDocsOnSave:true,
	exportedFileExtension: ".tga" // Not fully support, don't change!
};

// MAP CONSTRUCTOR (includes defaults)
var Map = function(defaultLayerName, defaultAlphaLayerName, filePostfix, alphaState)
{
	this.defaultLayerName = defaultLayerName;
	this.defaultAlphaLayerName = defaultAlphaLayerName;
	
	this.filePostfix = filePostfix;
	
	this.exportMap = false;
	this.exportAlpha = false;
	
	this.rgbLayerIndex = 0;
	this.alphaLayerIndex = 0;
	
	this.alphaState = alphaState;
	
	this.setLayerIndexes = function(rgb, a)
	{
		this.rgbLayerIndex = rgb;
		this.alphaLayerIndex = a;
		
		this.exportMap = rgb > 0 ? true : false;
		this.exportAlpha = a > 0 ? true : false;
	};
	
	this.selectedToExport = function()
	{
		return this.exportMap || this.exportAlpha;
	}
	
	this.readyToExport = function()
	{
		if (!this.exportMap && this.exportAlpha)
		{
			errorsLog += "- The " + this.defaultLayerName + " map won't be exported. You can't export an Alpha channel without an RGB channel.\n\n";
			
			return false;
		}
		else if (this.exportMap && (!this.exportAlpha && this.alphaState == alpha.REQUIRED))
		{
			errorsLog += "- The " + this.defaultLayerName + " map won't be exported. The required Alpha channel wasn't specified.\n\n";
			
			return false;
		}
		else if (this.exportMap && (this.exportAlpha && this.alphaState == alpha.DISABLED))
		{
			errorsLog += "- The " + this.defaultLayerName + " map won't be exported. The Alpha channel can't be exported on this map.\n\n";
			
			return false;
		}
		
		return true;
	}
}

var alpha = { AVAILABLE: 0, REQUIRED: 1, DISABLED: 2 }

//TODO: Loop to create form sections for each variable created here
var maps = {};
maps.albedo = new Map("albedo", "", "_albedo", alpha.AVAILABLE);
maps.normal = new Map("normal", "", "_normal", alpha.AVAILABLE);
maps.metallic = new Map("metallic", "smoothness", "_metallic", alpha.REQUIRED);

// Document caches
var doc;	// Active document
var docFilename;	// Document filename
var docPath;	// Document path

// Other variables
var exportedFilename;	// Filename for exported file
var exportedFilePath;	// Path for exported file
var errorsLog;	// Error log

// Let the fun begin...
function showDialog()
{
	// Create the window
	var win = new Window ("dialog", "Export PBR textures");
	var mainPanel = win.add("panel", undefined, "Export Textures");
	
	// Add a group for the export path
	var folderGroup = mainPanel.add("group");
	folderGroup.add("statictext", undefined, "Export folder: ");
	var exportPath = folderGroup.add("edittext", undefined, docPath.fsName);
	exportPath.size = [400, ""];
	var selectFolderBtn = folderGroup.add ("iconbutton", undefined, "DestinationFolderIcon");
	//TODO: Option to enter base filename
	
	// Add a panel for the albedo map labels and drop-downs
	var albedoGroup = mainPanel.add("panel", undefined, "Albedo map:");
	albedoGroup.orientation = "row";
	
	albedoGroup.add("statictext", undefined, "RGB channel: ");
	var albedoRGB = albedoGroup.add("listbox");
	albedoRGB.size = "width: 120, height: 120";
	populateList(albedoRGB, maps.albedo.defaultLayerName);
	
	albedoGroup.add("statictext", undefined, "Alpha channel: ");
	var albedoAlpha = albedoGroup.add("listbox");
	albedoAlpha.size = "width: 120, height: 120";
	populateList(albedoAlpha, maps.albedo.defaultAlphaLayerName);
	
	// Add a panel for the normal map labels and drop-downs
	var normalGroup = mainPanel.add("panel", undefined, "Normal map:");
	normalGroup.orientation = "row";
	
	normalGroup.add("statictext", undefined, "RGB channel: ");
	var normalRGB = normalGroup.add("listbox");
	normalRGB.size = "width: 120, height: 120";
	populateList(normalRGB, maps.normal.defaultLayerName);
	
	normalGroup.add("statictext", undefined, "Alpha channel: ");
	var normalAlpha = normalGroup.add("listbox");
	normalAlpha.size = "width: 120, height: 120";
	populateList(normalAlpha, maps.normal.defaultAlphaLayerName);
	
	// Add a group for the metallic map labels and drop-downs
	var metallicGroup = mainPanel.add("panel", undefined, "Metallic map:");
	metallicGroup.orientation = "row";
	
	metallicGroup.add("statictext", undefined, "RGB channel: ");
	var metallicRGB = metallicGroup.add("listbox");
	metallicRGB.size = "width: 120, height: 120";
	populateList(metallicRGB, maps.metallic.defaultLayerName);
	
	metallicGroup.add("statictext", undefined, "Alpha channel: ");
	var metallicAlpha = metallicGroup.add("listbox");
	metallicAlpha.size = "width: 120, height: 120";
	populateList(metallicAlpha, maps.metallic.defaultAlphaLayerName);
	
	// Export options group
	var optionsGroup = mainPanel.add("panel", undefined, "Export options");
	var autoSaveCheckbox = optionsGroup.add("checkbox", undefined, "Auto-save files (Overwrites any existing files)");
	autoSaveCheckbox.value = options.autoSave;
	var lowercaseCheckbox = optionsGroup.add("checkbox", undefined, "Convert filename to lowercase ('ExportMap' to 'exportmap')");
	lowercaseCheckbox.value = options.lowercaseFilename;
	var removeSpacesCheckbox = optionsGroup.add("checkbox", undefined, "Convert filename spaces to underscores ('export map' to 'export_map')");
	removeSpacesCheckbox.value = options.removeFilenameSpaces;
	var closeOnSaveCheckbox = optionsGroup.add("checkbox", undefined, "Close exported documents when auto-saved");
	closeOnSaveCheckbox.value = options.closeDocsOnSave;
	
	// Add buttons group
	var buttonGroup = mainPanel.add("group");
	var exportBtn = buttonGroup.add("button", undefined, "Export maps", {name: "ok"});
	var cancelBtn = buttonGroup.add("button", undefined, "Cancel");
	
	// CALLBACKS -- SELECT FOLDER
	selectFolderBtn.onClick = function ()
	{
		var newPath = docPath.selectDlg("Select a folder to export to: ");
		
		if (newPath != null)
		{
			exportPath.text = newPath.fsName;
		}
		
	}
	
	// CALLBACKS -- EXPORT
	exportBtn.onClick = function ()
	{
		options.autoSave = autoSaveCheckbox.value;
		options.lowercaseFilename = lowercaseCheckbox.value;
		options.removeFilenameSpaces = removeSpacesCheckbox.value;
		options.closeDocsOnSave = closeOnSaveCheckbox.value;
		
		exportedFilePath = exportPath.text;
		
		maps.albedo.setLayerIndexes(albedoRGB.selection, albedoAlpha.selection);
		maps.normal.setLayerIndexes(normalRGB.selection, normalAlpha.selection);
		maps.metallic.setLayerIndexes(metallicRGB.selection, metallicAlpha.selection);
		
		if (validateForm()) win.close(1);   // If validation passes
		else { alert(errorsLog); }
		
		errorsLog = "The following errors occurred: \n\n";
	}
	
	if (win.show() == 1)
	{
		errorsLog = "The following errors occurred: \n\n";
		return 0;
	}
	else
	{
		return 1;
	}
}

function populateList (list, defaultLayerName)
{
	list.add("item", "None");
	list.selection = 0;
	
	for (var i = 0; i < doc.layerSets.length; i++)
	{
		var layerName = doc.layerSets[i].name;
		
		list.add("item", layerName);
		
		if (layerName.toLowerCase() == defaultLayerName)
		{
			list.selection = list.find(layerName);
		}
	}
}

function validateForm ()
{
	if (exportMapSelectionsValid() && folderExists ()) return true;
}

function exportMapSelectionsValid ()
{
	var mapsToExport = 0;
	var errorsCount = 0;
	
	for (var map in maps)
	{
		if (maps[map].selectedToExport())
		{
			if (!maps[map].readyToExport())
			{
				errorsCount++;
			}
			else
			{
				mapsToExport++;
			}
		}
	}
	
	if (mapsToExport == 0) { errorsLog += "- There are no maps selected for export.\n\n"; errorsCount++; }
	if (errorsCount > 0) return false;
	
	return true;
}

function folderExists ()
{
	if (exportedFilePath.exists) return true;
	else
	{
		var newPath = new Folder (exportedFilePath);
		
		if (newPath.create()) return true;
		else
		{
			errorsLog += "- The export folder doesn't exist and couldn't be created. Please check you've entered a valid path.\n\n";
			return false;
		}
	}
}

function getBaseFilename()
{
	if (options.lowercaseFilename) exportedFilename = exportedFilename.toLowerCase();
	if (options.removeFilenameSpaces) exportedFilename =  exportedFilename.replace (" ", "_");
}

function exportMaps(mapToExport)
{
	doc.activeChannels = doc.componentChannels;
	
	hideAllLayers ();
	
	var layerToExport = doc.layerSets[mapToExport.rgbLayerIndex];
	layerToExport.visible = true;
	doc.activeLayer = layerToExport;
	
	var selection = doc.selection.selectAll();
	doc.selection.copy (true);
	
	var newDoc = app.documents.add(doc.width, doc.height, doc.resolution, exportedFilename + mapToExport.filePostfix);
	
	newDoc.activeChannels = newDoc.componentChannels;
	newDoc.paste();
	
	if (mapToExport.exportAlpha)
	{
		app.activeDocument = doc;
		
		hideAllLayers ();
		
		var layerToExport = doc.layerSets[mapToExport.alphaLayerIndex];
		layerToExport.visible = true;
		doc.activeLayer = layerToExport;
		
		var selection = doc.selection.selectAll();
		doc.selection.copy (true);
		
		app.activeDocument = newDoc;
		var alphaChannel = newDoc.channels.add();
		newDoc.activeChannels = [alphaChannel];
		newDoc.paste();
		
		newDoc.activeChannels = newDoc.componentChannels;
	}
	
	if (options.autoSave)
	{
		saveFile(newDoc);
	}
	
	app.activeDocument = doc;
	doc.activeChannels = doc.componentChannels;
	doc.activeLayer = layerToExport;
}

function hideAllLayers ()
{
	for (var i = 0; i < doc.layerSets.length; i++)
	{    
		var currentLayer = doc.layerSets[i];
		currentLayer.visible = false;
	}
}

function saveFile ()
{
	var currentDoc = app.activeDocument;
	
	// Set SaveOptions
	tgaSaveOptions = new TargaSaveOptions();
	
	tgaSaveOptions.alphaChannels = currentDoc.channels.length > 3 ? true : false;
	tgaSaveOptions.resolution = currentDoc.channels.length > 3 ? TargaBitsPerPixels.THIRTYTWO : TargaBitsPerPixels.TWENTYFOUR;
	tgaSaveOptions.rleCompression = false;
	
	// Generate full file path
	fullSavePath = new File(exportedFilePath + "/" + currentDoc.name + options.exportedFileExtension);
	
	// Save the file
	currentDoc.saveAs(fullSavePath, tgaSaveOptions, true, Extension.LOWERCASE);
	
	if (options.closeDocsOnSave) currentDoc.close(SaveOptions.DONOTSAVECHANGES);
}

function main ()
{
	// Check there is an open document, otherwise quit
	if (app.documents.length == 0) { alert ("No active document."); return 1; }
	
	// Document caches
	doc = app.activeDocument;
	docFilename = doc.name.substr(0, doc.name.lastIndexOf('.'));
	docPath = doc.saved ? doc.path : Folder.myDocuments;
	
	if (doc.layerSets.length == 0) { alert ("There are no Layer Groups in the active document."); return 1; }
	
	// Other variables
	exportedFilename = docFilename;
	exportedFilePath = docPath;
	errorsLog = "The following errors occurred: \n\n";
	
	var result = showDialog();
	
	if (result == 0) // Form has passed validation
	{
		getBaseFilename();  // Get the updated filename
		
		for (var map in maps)
		{
			if (maps[map].selectedToExport() && maps[map].readyToExport())
			{
				exportMaps(maps[map]);
			}
		}
		
		alert("All textures exported.");
	}
	else
	{
		return 1;
	}
	
	return 0;
}

main();