Checker Map fixes

Fix #44
Original Materials are now restored when cycling Checker Maps from a dictionary stored in utilities_texel; this means, to not lose the original material assignations: MATERIALS SHOULD BE RESTORED BEFORE EXITING BLENDER / CHANGING THE BLEND FILE BEING EDITED.
The original materials won't be lost in any case, they will be marked as Fake Users while renamed with the prefix "backup_". Before, using this tool straigh deleted them and the materials slots, making imposible to reasign new materials easily in a multi-material object.
Checker Maps operates in both EDIT and OBJECT modes for multiple objects without issues.
The UV Editor back image won't be replaced by the "checker_map_gravity" map anymore.
Some cleanup in utilities_bake

op_texel_checker_map.py

@@ -12,7 +12,6 @@
 texture_modes = ['UV_GRID','COLOR_GRID','GRAVITY','NONE']
 
 
-
 class op(bpy.types.Operator):
 	bl_idname = "uv.textools_texel_checker_map"
 	bl_label = "Checker Map"
@@ -34,8 +33,6 @@ def execute(self, context):
 		return {'FINISHED'}
 
 
-
-
 def assign_checker_map(size_x, size_y):
 	# Force Object mode
 	previous_mode = bpy.context.active_object.mode
@@ -55,7 +52,6 @@ def assign_checker_map(size_x, size_y):
 				if space.type == 'VIEW_3D':
 					space.shading.type = 'MATERIAL'
 
-
 	if len(objects) > 0:
 
 		# Detect current Checker modes
@@ -84,6 +80,8 @@ def assign_checker_map(size_x, size_y):
 						image_sizes_x.append(image.size[0])
 					if image.size[1] not in image_sizes_y:
 						image_sizes_y.append(image.size[1])
+			else:
+				utilities_texel.store_materials(obj)
 
 			mode_count[mode]+=1
 
@@ -95,7 +93,6 @@ def assign_checker_map(size_x, size_y):
 		for key,val in mode_max_count:
 			print("{} = {}".format(key, val))
 
-
 		# Determine next mode
 		mode = 'NONE'
 		if mode_max_count[0][1] == 0:
@@ -120,16 +117,23 @@ def assign_checker_map(size_x, size_y):
 				else:
 					# Next mode
 					mode = texture_modes[ (index+1)%len(texture_modes) ]
-
-
-		print("Mode: "+mode)
-
-		if mode == 'NONE':
+
+		if mode == 'UV_GRID':
+			name = utilities_texel.get_checker_name(mode, size_x, size_y)
+			image = get_image(name, mode, size_x, size_y)
 			for obj in objects:
-				remove_material(obj)
+				apply_image(obj, image)
+
+		elif mode == 'NONE':
+			utilities_texel.restore_materials(objects)
 
 		elif mode == 'GRAVITY':
-			image = load_image("checker_map_gravity")
+			for area in bpy.context.screen.areas:
+				if area.type == 'IMAGE_EDITOR':
+					editorImage = area.spaces[0].image
+					image = load_image("checker_map_gravity")
+					area.spaces[0].image = editorImage
+					break
 			for obj in objects:
 				apply_image(obj, image)
 
@@ -159,8 +163,8 @@ def load_image(name):
 	pathTexture = icons_dir = os.path.join(os.path.dirname(__file__), "resources/{}.png".format(name))
 	image = bpy.ops.image.open(filepath=pathTexture, relative_path=False)
 	if "{}.png".format(name) in bpy.data.images:
-		bpy.data.images["{}.png".format(name)].name = name #remove extension in name
-	return bpy.data.images[name];
+		bpy.data.images["{}.png".format(name)].name = name	#remove extension in name
+	return bpy.data.images[name]
 
 
 
@@ -169,27 +173,11 @@ def get_valid_objects():
 	objects = []
 	for obj in bpy.context.selected_objects:
 		if obj.type == 'MESH' and obj.data.uv_layers:
-				objects.append(obj)
-
+			objects.append(obj)
 	return objects
 
 
 
-
-
-
-
-def remove_material(obj):
-	bpy.ops.object.mode_set(mode='OBJECT')
-	bpy.ops.object.select_all(action='DESELECT')
-	obj.select_set( state = True, view_layer = None)
-	bpy.context.view_layer.objects.active = obj
-	count = len(obj.material_slots)
-	for i in range(count):
-		bpy.ops.object.material_slot_remove()
-
-
-
 def apply_image(obj, image):
 
 	bpy.ops.object.mode_set(mode='OBJECT')
@@ -209,7 +197,8 @@ def apply_image(obj, image):
 
 	# Assign material
 	if len(obj.data.materials) > 0:
-		obj.data.materials[0] = material
+		for m in range(len(obj.data.materials)):
+			obj.data.materials[m] = material
 	else:
 		obj.data.materials.append(material)
 
@@ -233,19 +222,20 @@ def apply_image(obj, image):
 	links.new(nodo1.outputs['Color'], nodo2.inputs['Base Color'])
 
 
+
 def get_image(name, mode, size_x, size_y):
 	# Image already exists?
 	if name in bpy.data.images:
 		# Update texture UV checker mode
 		bpy.data.images[name].generated_type = mode
-		return bpy.data.images[name];
+		return bpy.data.images[name]
 
 	# Create new image instead
 	image = bpy.data.images.new(name, width=size_x, height=size_y)
 	image.generated_type = mode #UV_GRID or COLOR_GRID
 	image.generated_width = int(size_x)
 	image.generated_height = int(size_y)
-
 	return image
 
+
 bpy.utils.register_class(op)

utilities_bake.py

@@ -9,7 +9,6 @@
 
 from . import settings
 from . import utilities_color
-# from . import op_bake
 
 
 keywords_low = ['lowpoly','low','lowp','lp','lo','l']
@@ -132,7 +131,7 @@ def store_materials(obj):
 	bpy.context.view_layer.objects.active = obj
 
 	bpy.ops.object.mode_set(mode='EDIT')
-	bm = bmesh.from_edit_mesh(obj.data);
+	bm = bmesh.from_edit_mesh(obj.data)
 
 	# for each slot backup the material 
 	for s in range(len(obj.material_slots)):
@@ -157,7 +156,7 @@ def restore_materials():
 		# Enter edit mode
 		bpy.context.view_layer.objects.active = obj
 		bpy.ops.object.mode_set(mode='EDIT')
-		bm = bmesh.from_edit_mesh(obj.data);
+		bm = bmesh.from_edit_mesh(obj.data)
 
 		# Restore slots
 		for index in range(len(stored_materials[obj])):
@@ -177,7 +176,7 @@ def restore_materials():
 		bpy.ops.object.mode_set(mode='OBJECT')
 
 		# Remove material slots if none before
-		if len(stored_materials[obj]) == 0:
+		if len(stored_materials[obj]) == 0 :
 			for i in range(len(obj.material_slots)):
 				bpy.ops.object.material_slot_remove()
 

utilities_texel.py

@@ -136,3 +136,88 @@ def get_area_triangle(A,B,C):
 
 	# Use abs(s-a) for values that otherwise generate negative values e.g. pinched UV verts, otherwise math domain error
 	return math.sqrt(s * abs(s-a) * abs(s-b) * abs(s-c))
+
+
+
+stored_materials = {}
+stored_material_faces = {}
+def store_materials_clear():
+	stored_materials.clear()
+	stored_material_faces.clear()
+
+
+
+def store_materials(obj):
+	stored_materials[obj] = []
+	stored_material_faces[obj] = []
+
+	# Enter edit mode
+	bpy.ops.object.select_all(action='DESELECT')
+	obj.select_set( state = True, view_layer = None)
+	bpy.context.view_layer.objects.active = obj
+
+	bpy.ops.object.mode_set(mode='EDIT')
+	bm = bmesh.from_edit_mesh(obj.data)
+
+	# for each slot backup the material 
+	for s in range(len(obj.material_slots)):
+		slot = obj.material_slots[s]
+
+		stored_materials[obj].append(slot.material)
+		stored_material_faces[obj].append( [face.index for face in bm.faces if face.material_index == s] )
+
+		# print("Faces: {}x".format( len(stored_material_faces[obj][-1])  ))
+
+		if slot and slot.material:
+			slot.material.name = "backup_"+slot.material.name
+			slot.material.use_fake_user = True
+			print("- Store {} = {}".format(obj.name,slot.material.name))
+
+	# Back to object mode
+	bpy.ops.object.mode_set(mode='OBJECT')
+
+
+
+def restore_materials(objs):
+	if len(objs) == 0 :
+		return
+	else:
+		for obj in objs :
+			if stored_materials.get(obj) == None :
+				bpy.ops.object.mode_set(mode='OBJECT')
+				bpy.ops.object.select_all(action='DESELECT')
+				obj.select_set( state = True, view_layer = None)
+				bpy.context.view_layer.objects.active = obj
+				count = len(obj.material_slots)
+				for i in range(count):
+					bpy.ops.object.material_slot_remove()
+		objs = [obj for obj in objs if obj in stored_materials]
+
+	for obj in objs :
+		# Enter edit mode
+		bpy.context.view_layer.objects.active = obj
+		bpy.ops.object.mode_set(mode='EDIT')
+		bm = bmesh.from_edit_mesh(obj.data)
+
+		# Restore slots
+		for index in range(len(stored_materials[obj])):
+			material = stored_materials[obj][index]
+			faces = stored_material_faces[obj][index]
+
+			if material:
+				material.name = material.name.replace("backup_","")
+				obj.material_slots[index].material = material
+				material.use_fake_user = False
+
+				# Face material indexies
+				for face in bm.faces:
+					if face.index in faces:
+						face.material_index = index
+
+		# Back to object mode
+		bpy.ops.object.mode_set(mode='OBJECT')
+
+		# Remove material slots if none before
+		if len(stored_materials[obj]) == 0 :
+			for i in range(len(obj.material_slots)):
+				bpy.ops.object.material_slot_remove()