diff --git a/addons/material_maker/engine/gen_debug.gd b/addons/material_maker/engine/gen_debug.gd
new file mode 100644
index 0000000..7065181
--- /dev/null
+++ b/addons/material_maker/engine/gen_debug.gd
@@ -0,0 +1,16 @@
+tool
+extends MMGenBase
+class_name MMGenDebug
+
+"""
+Can be used to get generated shader
+"""
+
+func get_type() -> String:
+	return "debug"
+
+func get_type_name() -> String:
+	return "Debug"
+
+func get_input_defs() -> Array:
+	return [ { name="in", type="rgba" } ]
diff --git a/addons/material_maker/engine/gen_export.gd b/addons/material_maker/engine/gen_export.gd
new file mode 100644
index 0000000..7ebc3e7
--- /dev/null
+++ b/addons/material_maker/engine/gen_export.gd
@@ -0,0 +1,54 @@
+tool
+extends MMGenBase
+class_name MMGenExport
+
+"""
+Can be used to export an additional texture
+"""
+
+var texture = null
+
+# The default texture size as a power-of-two exponent
+const TEXTURE_SIZE_DEFAULT = 10  # 1024x1024
+
+func get_image_size() -> int:
+	var rv : int
+	if parameters.has("size"):
+		rv = int(pow(2, parameters.size))
+	else:
+		rv = int(pow(2, TEXTURE_SIZE_DEFAULT))
+	return rv
+
+func get_type() -> String:
+	return "export"
+
+func get_type_name() -> String:
+	return "Export"
+
+func get_parameter_defs() -> Array:
+	return [
+			{ name="size", type="size", first=4, last=12, default=10 },
+			{ name="suffix", type="string", default="suffix" }
+		]
+
+func get_input_defs() -> Array:
+	return [ { name="in", type="rgba" } ]
+
+func render_textures(renderer : MMGenRenderer) -> void:
+	print("rendering texture...")
+	var source = get_source(0)
+	if source != null:
+		var result = source.generator.render(source.output_index, renderer, get_image_size())
+		while result is GDScriptFunctionState:
+			result = yield(result, "completed")
+		texture = ImageTexture.new()
+		result.copy_to_texture(texture)
+		result.release()
+	else:
+		texture = null
+
+func export_textures(prefix, __ = null) -> void:
+	print("exporting texture")
+	if texture != null:
+		var image = texture.get_data()
+		image.save_png("%s_%s.png" % [ prefix, parameters.suffix])
diff --git a/addons/material_maker/engine/gen_shader.gd b/addons/material_maker/engine/gen_shader.gd
index ca87782..7c0a77b 100644
--- a/addons/material_maker/engine/gen_shader.gd
+++ b/addons/material_maker/engine/gen_shader.gd
@@ -176,7 +176,7 @@ func subst(string, context, uv = "") -> Dictionary:
 			elif p.type == "color":
 				value_string = "vec4(%.9f, %.9f, %.9f, %.9f)" % [ value.r, value.g, value.b, value.a ]
 			elif p.type == "gradient":
-				value_string = genname+"__"+p.name+"_gradient_fct"
+				value_string = genname+"_p_"+p.name+"_gradient_fct"
 			elif p.type == "boolean":
 				value_string = "true" if value else "false"
 			else:
@@ -232,7 +232,7 @@ func _get_shader_code(uv : String, output_index : int, context : MMGenContext) -
 					if !(g is MMGradient):
 						g = MMGradient.new()
 						g.deserialize(parameters[p.name])
-					rv.defs += g.get_shader(genname+"__"+p.name+"_gradient_fct")
+					rv.defs += g.get_shader(genname+"_p_"+p.name+"_gradient_fct")
 		# Add inline code
 		if shader_model.has("code"):
 			var variant_index = context.get_variant(self, uv)
diff --git a/addons/material_maker/engine/loader.gd b/addons/material_maker/engine/loader.gd
index 648c1c6..1b6beeb 100644
--- a/addons/material_maker/engine/loader.gd
+++ b/addons/material_maker/engine/loader.gd
@@ -48,7 +48,9 @@ static func create_gen(data) -> MMGenBase:
 		material = MMGenMaterial,
 		buffer = MMGenBuffer,
 		image = MMGenImage,
-		switch = MMGenSwitch
+		switch = MMGenSwitch,
+		export = MMGenExport,
+		debug = MMGenDebug
 	}
 	var generator = null
 	if data.has("connections") and data.has("nodes"):
@@ -69,23 +71,17 @@ static func create_gen(data) -> MMGenBase:
 		generator = MMGenRemote.new()
 		generator.set_widgets(data.widgets.duplicate(true))
 	elif data.has("type"):
-		if data.type == "material":
-			generator = MMGenMaterial.new()
-		elif data.type == "buffer":
-			generator = MMGenBuffer.new()
+		if types.has(data.type):
+			generator = types[data.type].new()
 		elif data.type == "comment":
 			generator = MMGenComment.new()
 			if data.has("text"):
 				generator.text = data.text
 			if data.has("size"):
 				generator.size = Vector2(data.size.x, data.size.y)
-		elif data.type == "image":
-			generator = MMGenImage.new()
 		elif data.type == "ios":
 			generator = MMGenIOs.new()
 			generator.ports = data.ports
-		elif data.type == "switch":
-			generator = MMGenSwitch.new()
 		else:
 			var file = File.new()
 			var gen_paths = [ STD_GENDEF_PATH, OS.get_executable_path().get_base_dir()+"/generators" ]
diff --git a/addons/material_maker/graph_edit.gd b/addons/material_maker/graph_edit.gd
index 2e751d1..d9fcb24 100644
--- a/addons/material_maker/graph_edit.gd
+++ b/addons/material_maker/graph_edit.gd
@@ -207,8 +207,11 @@ func export_textures() -> void:
 	if save_path != null:
 		var prefix = save_path.left(save_path.rfind("."))
 		for c in get_children():
-			if c is GraphNode and c.generator.has_method("export_textures"):
-				c.generator.export_textures(prefix, editor_interface)
+			if c is GraphNode:
+				if c.generator.has_method("render_textures"):
+					c.generator.render_textures(renderer)
+					if c.generator.has_method("export_textures"):
+						c.generator.export_textures(prefix, editor_interface)
 
 # Cut / copy / paste
 
@@ -270,8 +273,10 @@ func paste(pos = Vector2(0, 0)) -> void:
 		if c is GraphNode:
 			c.selected = false
 	var data = parse_json(OS.clipboard)
-	for c in create_nodes(data, scroll_offset+0.5*rect_size):
-		c.selected = true
+	var new_nodes = create_nodes(data, scroll_offset+0.5*rect_size)
+	if new_nodes != null:
+		for c in new_nodes:
+			c.selected = true
 
 # Delay after graph update
 
diff --git a/addons/material_maker/library/base.json b/addons/material_maker/library/base.json
index 3d9383c..b0ef25c 100644
--- a/addons/material_maker/library/base.json
+++ b/addons/material_maker/library/base.json
@@ -406,5 +406,15 @@
 	{
 		"tree_item":"Miscellaneous/Comment",
 		"type":"comment"
+	},
+	{
+		"tree_item":"Miscellaneous/Export",
+		"type":"export",
+		"parameters":{"size":10}
+	},
+	{
+		"tree_item":"Miscellaneous/Debug",
+		"icon":"debug",
+		"type":"debug"
 	}
 ]}
\ No newline at end of file
diff --git a/addons/material_maker/library/base/debug.png b/addons/material_maker/library/base/debug.png
new file mode 100644
index 0000000..ca85e2d
Binary files /dev/null and b/addons/material_maker/library/base/debug.png differ
diff --git a/addons/material_maker/nodes/debug.gd b/addons/material_maker/nodes/debug.gd
new file mode 100644
index 0000000..5cce0e9
--- /dev/null
+++ b/addons/material_maker/nodes/debug.gd
@@ -0,0 +1,32 @@
+extends MMGraphNodeBase
+
+static func generate_shader(src_code) -> String:
+	var code
+	code = ""
+	var file = File.new()
+	file.open("res://addons/material_maker/common.shader", File.READ)
+	code += file.get_as_text()
+	code += "\n"
+	if src_code.has("textures"):
+		for t in src_code.textures.keys():
+			code += "uniform sampler2D "+t+";\n"
+	if src_code.has("globals"):
+		for g in src_code.globals:
+			code += g
+	var shader_code = src_code.defs
+	shader_code += "\nvoid mainImage(out vec4 fragColor, in vec2 fragCoord) {\nvec2 UV = fragCoord/iResolution.xy;\n"
+	shader_code += src_code.code
+	shader_code += "fragColor = "+src_code.rgba+";\n"
+	shader_code += "}\n"
+	#print("GENERATED SHADER:\n"+shader_code)
+	code += shader_code
+	return code
+
+func _on_Button_pressed():
+	var src = generator.get_source(0)
+	if src != null:
+		var context : MMGenContext = MMGenContext.new(null)
+		var source = src.generator.get_shader_code("UV", src.output_index, context)
+		var popup = preload("res://addons/material_maker/nodes/debug/debug_popup.tscn").instance()
+		get_parent().add_child(popup)
+		popup.show_code(generate_shader(source))
diff --git a/addons/material_maker/nodes/debug.tscn b/addons/material_maker/nodes/debug.tscn
new file mode 100644
index 0000000..52a95e0
--- /dev/null
+++ b/addons/material_maker/nodes/debug.tscn
@@ -0,0 +1,24 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://addons/material_maker/nodes/debug.gd" type="Script" id=1]
+
+[node name="Debug" type="GraphNode"]
+margin_right = 124.0
+margin_bottom = 49.0
+title = "Debug"
+show_close = true
+slot/0/left_enabled = true
+slot/0/left_type = 0
+slot/0/left_color = Color( 0, 1, 0, 0.501961 )
+slot/0/right_enabled = false
+slot/0/right_type = 0
+slot/0/right_color = Color( 1, 1, 1, 1 )
+script = ExtResource( 1 )
+
+[node name="Button" type="Button" parent="."]
+margin_left = 16.0
+margin_top = 24.0
+margin_right = 108.0
+margin_bottom = 44.0
+text = "Show shader"
+[connection signal="pressed" from="Button" to="." method="_on_Button_pressed"]
diff --git a/addons/material_maker/nodes/debug/debug_popup.gd b/addons/material_maker/nodes/debug/debug_popup.gd
new file mode 100644
index 0000000..82447eb
--- /dev/null
+++ b/addons/material_maker/nodes/debug/debug_popup.gd
@@ -0,0 +1,5 @@
+extends Popup
+
+func show_code(text : String) -> void:
+	$TextEdit.text = text
+	popup_centered()
\ No newline at end of file
diff --git a/addons/material_maker/nodes/debug/debug_popup.tscn b/addons/material_maker/nodes/debug/debug_popup.tscn
new file mode 100644
index 0000000..2a8747e
--- /dev/null
+++ b/addons/material_maker/nodes/debug/debug_popup.tscn
@@ -0,0 +1,16 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://addons/material_maker/nodes/debug/debug_popup.gd" type="Script" id=1]
+
+[node name="Popup" type="Popup"]
+visible = true
+margin_right = 739.0
+margin_bottom = 662.0
+rect_min_size = Vector2( 500, 300 )
+script = ExtResource( 1 )
+
+[node name="TextEdit" type="TextEdit" parent="."]
+anchor_right = 1.0
+anchor_bottom = 1.0
+syntax_highlighting = true
+show_line_numbers = true
diff --git a/addons/material_maker/nodes/generic.gd b/addons/material_maker/nodes/generic.gd
index 9c145a6..d02e8c5 100644
--- a/addons/material_maker/nodes/generic.gd
+++ b/addons/material_maker/nodes/generic.gd
@@ -25,7 +25,7 @@ func on_parameter_changed(p, v) -> void:
 	elif controls.has(p):
 		var o = controls[p]
 		if o is LineEdit:
-			o.text = str(v)
+			o.text = v
 		elif o is SpinBox:
 			o.value = v
 		elif o is HSlider:
@@ -81,7 +81,7 @@ func update_shaders() -> void:
 
 func _on_text_changed(new_text, variable) -> void:
 	ignore_parameter_change = variable
-	generator.set_parameter(variable, float(new_text))
+	generator.set_parameter(variable, new_text)
 	ignore_parameter_change = ""
 	update_shaders()
 
@@ -135,6 +135,8 @@ func create_parameter_control(p : Dictionary) -> Control:
 		control = ColorPickerButton.new()
 	elif p.type == "gradient":
 		control = preload("res://addons/material_maker/widgets/gradient_editor.tscn").instance()
+	elif p.type == "string":
+		control = LineEdit.new()
 	return control
 
 func save_preview_widget() -> void:
diff --git a/project.godot b/project.godot
index 210aeb8..82e6091 100644
--- a/project.godot
+++ b/project.godot
@@ -35,6 +35,16 @@ _global_script_classes=[ {
 "path": "res://addons/material_maker/engine/gen_convolution.gd"
 }, {
 "base": "MMGenBase",
+"class": "MMGenDebug",
+"language": "GDScript",
+"path": "res://addons/material_maker/engine/gen_debug.gd"
+}, {
+"base": "MMGenBase",
+"class": "MMGenExport",
+"language": "GDScript",
+"path": "res://addons/material_maker/engine/gen_export.gd"
+}, {
+"base": "MMGenBase",
 "class": "MMGenGraph",
 "language": "GDScript",
 "path": "res://addons/material_maker/engine/gen_graph.gd"
@@ -135,6 +145,8 @@ _global_script_class_icons={
 "MMGenComment": "",
 "MMGenContext": "",
 "MMGenConvolution": "",
+"MMGenDebug": "",
+"MMGenExport": "",
 "MMGenGraph": "",
 "MMGenIOs": "",
 "MMGenImage": "",