Editor: Fix serialization of commands. (#28405)

* Editor: Fix serialization of commands.

* Editor: Restore order in `fromJSON()`.

* Editor: Fix regression when adding/removing scripts.

editor/js/Sidebar.Scene.js

@@ -522,13 +522,13 @@ function SidebarScene( editor ) {
 
 	signals.scriptAdded.add( function () {
 
-		signals.objectChanged.dispatch( editor.selected );
+		if ( editor.selected !== null ) signals.objectChanged.dispatch( editor.selected );
 
 	} );
 
 	signals.scriptRemoved.add( function () {
 
-		signals.objectChanged.dispatch( editor.selected );
+		if ( editor.selected !== null ) signals.objectChanged.dispatch( editor.selected );
 
 	} );
 

editor/js/commands/AddObjectCommand.js

@@ -8,14 +8,15 @@ import { ObjectLoader } from 'three';
  */
 class AddObjectCommand extends Command {
 
-	constructor( editor, object ) {
+	constructor( editor, object = null ) {
 
 		super( editor );
 
 		this.type = 'AddObjectCommand';
 
 		this.object = object;
-		if ( object !== undefined ) {
+
+		if ( object !== null ) {
 
 			this.name = editor.strings.getKey( 'command/AddObject' ) + ': ' + object.name;
 

editor/js/commands/AddScriptCommand.js

@@ -8,7 +8,7 @@ import { Command } from '../Command.js';
  */
 class AddScriptCommand extends Command {
 
-	constructor( editor, object, script ) {
+	constructor( editor, object = null, script = '' ) {
 
 		super( editor );
 

editor/js/commands/MoveObjectCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class MoveObjectCommand extends Command {
 
-	constructor( editor, object, newParent, newBefore ) {
+	constructor( editor, object = null, newParent = null, newBefore = null ) {
 
 		super( editor );
 
@@ -17,17 +17,17 @@ class MoveObjectCommand extends Command {
 		this.name = editor.strings.getKey( 'command/MoveObject' );
 
 		this.object = object;
-		this.oldParent = ( object !== undefined ) ? object.parent : undefined;
-		this.oldIndex = ( this.oldParent !== undefined ) ? this.oldParent.children.indexOf( this.object ) : undefined;
+		this.oldParent = ( object !== null ) ? object.parent : null;
+		this.oldIndex = ( this.oldParent !== null ) ? this.oldParent.children.indexOf( this.object ) : null;
 		this.newParent = newParent;
 
-		if ( newBefore !== undefined ) {
+		if ( newBefore !== null ) {
 
-			this.newIndex = ( newParent !== undefined ) ? newParent.children.indexOf( newBefore ) : undefined;
+			this.newIndex = ( newParent !== null ) ? newParent.children.indexOf( newBefore ) : null;
 
 		} else {
 
-			this.newIndex = ( newParent !== undefined ) ? newParent.children.length : undefined;
+			this.newIndex = ( newParent !== null ) ? newParent.children.length : null;
 
 		}
 

editor/js/commands/MultiCmdsCommand.js

@@ -7,14 +7,14 @@ import { Command } from '../Command.js';
  */
 class MultiCmdsCommand extends Command {
 
-	constructor( editor, cmdArray ) {
+	constructor( editor, cmdArray = [] ) {
 
 		super( editor );
 
 		this.type = 'MultiCmdsCommand';
 		this.name = editor.strings.getKey( 'command/MultiCmds' );
 
-		this.cmdArray = ( cmdArray !== undefined ) ? cmdArray : [];
+		this.cmdArray = cmdArray;
 
 	}
 

editor/js/commands/RemoveObjectCommand.js

@@ -9,21 +9,28 @@ import { ObjectLoader } from 'three';
  */
 class RemoveObjectCommand extends Command {
 
-	constructor( editor, object ) {
+	constructor( editor, object = null ) {
 
 		super( editor );
 
 		this.type = 'RemoveObjectCommand';
-		this.name = editor.strings.getKey( 'command/RemoveObject' ) + ': ' + object.name;
 
 		this.object = object;
-		this.parent = ( object !== undefined ) ? object.parent : undefined;
-		if ( this.parent !== undefined ) {
+		this.parent = ( object !== null ) ? object.parent : null;
+
+		if ( this.parent !== null ) {
 
 			this.index = this.parent.children.indexOf( this.object );
 
 		}
 
+		if ( object !== null ) {
+
+			this.name = editor.strings.getKey( 'command/RemoveObject' ) + ': ' + object.name;
+
+
+		}
+
 	}
 
 	execute() {

editor/js/commands/RemoveScriptCommand.js

@@ -8,7 +8,7 @@ import { Command } from '../Command.js';
  */
 class RemoveScriptCommand extends Command {
 
-	constructor( editor, object, script ) {
+	constructor( editor, object = null, script = '' ) {
 
 		super( editor );
 
@@ -17,7 +17,8 @@ class RemoveScriptCommand extends Command {
 
 		this.object = object;
 		this.script = script;
-		if ( this.object && this.script ) {
+
+		if ( this.object !== null && this.script !== '' ) {
 
 			this.index = this.editor.scripts[ this.object.uuid ].indexOf( this.script );
 

editor/js/commands/SetColorCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class SetColorCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue ) {
+	constructor( editor, object = null, attributeName = '', newValue = null ) {
 
 		super( editor );
 
@@ -19,7 +19,7 @@ class SetColorCommand extends Command {
 
 		this.object = object;
 		this.attributeName = attributeName;
-		this.oldValue = ( object !== undefined ) ? this.object[ this.attributeName ].getHex() : undefined;
+		this.oldValue = ( object !== null ) ? this.object[ this.attributeName ].getHex() : null;
 		this.newValue = newValue;
 
 	}

editor/js/commands/SetGeometryCommand.js

@@ -10,7 +10,7 @@ import { ObjectLoader } from 'three';
 
 class SetGeometryCommand extends Command {
 
-	constructor( editor, object, newGeometry ) {
+	constructor( editor, object = null, newGeometry = null ) {
 
 		super( editor );
 
@@ -19,7 +19,7 @@ class SetGeometryCommand extends Command {
 		this.updatable = true;
 
 		this.object = object;
-		this.oldGeometry = ( object !== undefined ) ? object.geometry : undefined;
+		this.oldGeometry = ( object !== null ) ? object.geometry : null;
 		this.newGeometry = newGeometry;
 
 	}

editor/js/commands/SetGeometryValueCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class SetGeometryValueCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue ) {
+	constructor( editor, object = null, attributeName = '', newValue = null ) {
 
 		super( editor );
 
@@ -18,7 +18,7 @@ class SetGeometryValueCommand extends Command {
 
 		this.object = object;
 		this.attributeName = attributeName;
-		this.oldValue = ( object !== undefined ) ? object.geometry[ attributeName ] : undefined;
+		this.oldValue = ( object !== null ) ? object.geometry[ attributeName ] : null;
 		this.newValue = newValue;
 
 	}

editor/js/commands/SetMaterialColorCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class SetMaterialColorCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue, materialSlot ) {
+	constructor( editor, object = null, attributeName = '', newValue = null, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -20,9 +20,9 @@ class SetMaterialColorCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.material = ( this.object !== undefined ) ? this.editor.getObjectMaterial( object, materialSlot ) : undefined;
+		const material = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 
-		this.oldValue = ( this.material !== undefined ) ? this.material[ attributeName ].getHex() : undefined;
+		this.oldValue = ( material !== null ) ? material[ attributeName ].getHex() : null;
 		this.newValue = newValue;
 
 		this.attributeName = attributeName;
@@ -31,7 +31,9 @@ class SetMaterialColorCommand extends Command {
 
 	execute() {
 
-		this.material[ this.attributeName ].setHex( this.newValue );
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ].setHex( this.newValue );
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -39,7 +41,9 @@ class SetMaterialColorCommand extends Command {
 
 	undo() {
 
-		this.material[ this.attributeName ].setHex( this.oldValue );
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ].setHex( this.oldValue );
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -59,6 +63,7 @@ class SetMaterialColorCommand extends Command {
 		output.attributeName = this.attributeName;
 		output.oldValue = this.oldValue;
 		output.newValue = this.newValue;
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -72,6 +77,7 @@ class SetMaterialColorCommand extends Command {
 		this.attributeName = json.attributeName;
 		this.oldValue = json.oldValue;
 		this.newValue = json.newValue;
+		this.materialSlot = json.materialSlot;
 
 	}
 

editor/js/commands/SetMaterialCommand.js

@@ -9,7 +9,7 @@ import { ObjectLoader } from 'three';
  */
 class SetMaterialCommand extends Command {
 
-	constructor( editor, object, newMaterial, materialSlot ) {
+	constructor( editor, object = null, newMaterial = null, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -19,7 +19,7 @@ class SetMaterialCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.oldMaterial = this.editor.getObjectMaterial( object, materialSlot );
+		this.oldMaterial = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 		this.newMaterial = newMaterial;
 
 	}
@@ -47,6 +47,7 @@ class SetMaterialCommand extends Command {
 		output.objectUuid = this.object.uuid;
 		output.oldMaterial = this.oldMaterial.toJSON();
 		output.newMaterial = this.newMaterial.toJSON();
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -59,6 +60,7 @@ class SetMaterialCommand extends Command {
 		this.object = this.editor.objectByUuid( json.objectUuid );
 		this.oldMaterial = parseMaterial( json.oldMaterial );
 		this.newMaterial = parseMaterial( json.newMaterial );
+		this.materialSlot = json.materialSlot;
 
 		function parseMaterial( json ) {
 

editor/js/commands/SetMaterialMapCommand.js

@@ -10,7 +10,7 @@ import { ObjectLoader } from 'three';
  */
 class SetMaterialMapCommand extends Command {
 
-	constructor( editor, object, mapName, newMap, materialSlot ) {
+	constructor( editor, object = null, mapName = '', newMap = null, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -20,9 +20,9 @@ class SetMaterialMapCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.material = this.editor.getObjectMaterial( object, materialSlot );
+		const material = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 
-		this.oldMap = ( object !== undefined ) ? this.material[ mapName ] : undefined;
+		this.oldMap = ( object !== null ) ? material[ mapName ] : undefined;
 		this.newMap = newMap;
 
 		this.mapName = mapName;
@@ -33,8 +33,10 @@ class SetMaterialMapCommand extends Command {
 
 		if ( this.oldMap !== null && this.oldMap !== undefined ) this.oldMap.dispose();
 
-		this.material[ this.mapName ] = this.newMap;
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.mapName ] = this.newMap;
+		material.needsUpdate = true;
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -42,8 +44,10 @@ class SetMaterialMapCommand extends Command {
 
 	undo() {
 
-		this.material[ this.mapName ] = this.oldMap;
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.mapName ] = this.oldMap;
+		material.needsUpdate = true;
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -57,6 +61,7 @@ class SetMaterialMapCommand extends Command {
 		output.mapName = this.mapName;
 		output.newMap = serializeMap( this.newMap );
 		output.oldMap = serializeMap( this.oldMap );
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -112,6 +117,7 @@ class SetMaterialMapCommand extends Command {
 		this.mapName = json.mapName;
 		this.oldMap = parseTexture( json.oldMap );
 		this.newMap = parseTexture( json.newMap );
+		this.materialSlot = json.materialSlot;
 
 		function parseTexture( json ) {
 

editor/js/commands/SetMaterialRangeCommand.js

@@ -10,7 +10,7 @@ import { Command } from '../Command.js';
  */
 class SetMaterialRangeCommand extends Command {
 
-	constructor( editor, object, attributeName, newMinValue, newMaxValue, materialSlot ) {
+	constructor( editor, object = null, attributeName = '', newMinValue = - Infinity, newMaxValue = Infinity, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -21,9 +21,9 @@ class SetMaterialRangeCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.material = this.editor.getObjectMaterial( object, materialSlot );
+		const material = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 
-		this.oldRange = ( this.material !== undefined && this.material[ attributeName ] !== undefined ) ? [ ...this.material[ attributeName ] ] : undefined;
+		this.oldRange = ( material !== null && material[ attributeName ] !== undefined ) ? [ ...this.material[ attributeName ] ] : null;
 		this.newRange = [ newMinValue, newMaxValue ];
 
 		this.attributeName = attributeName;
@@ -32,8 +32,10 @@ class SetMaterialRangeCommand extends Command {
 
 	execute() {
 
-		this.material[ this.attributeName ] = [ ...this.newRange ];
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ] = [ ...this.newRange ];
+		material.needsUpdate = true;
 
 		this.editor.signals.objectChanged.dispatch( this.object );
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
@@ -42,8 +44,10 @@ class SetMaterialRangeCommand extends Command {
 
 	undo() {
 
-		this.material[ this.attributeName ] = [ ...this.oldRange ];
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ] = [ ...this.oldRange ];
+		material.needsUpdate = true;
 
 		this.editor.signals.objectChanged.dispatch( this.object );
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
@@ -64,6 +68,7 @@ class SetMaterialRangeCommand extends Command {
 		output.attributeName = this.attributeName;
 		output.oldRange = [ ...this.oldRange ];
 		output.newRange = [ ...this.newRange ];
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -77,6 +82,7 @@ class SetMaterialRangeCommand extends Command {
 		this.oldRange = [ ...json.oldRange ];
 		this.newRange = [ ...json.newRange ];
 		this.object = this.editor.objectByUuid( json.objectUuid );
+		this.materialSlot = json.materialSlot;
 
 	}
 

editor/js/commands/SetMaterialValueCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class SetMaterialValueCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue, materialSlot ) {
+	constructor( editor, object = null, attributeName = '', newValue = null, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -20,9 +20,9 @@ class SetMaterialValueCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.material = this.editor.getObjectMaterial( object, materialSlot );
+		const material = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 
-		this.oldValue = ( this.material !== undefined ) ? this.material[ attributeName ] : undefined;
+		this.oldValue = ( material !== null ) ? material[ attributeName ] : null;
 		this.newValue = newValue;
 
 		this.attributeName = attributeName;
@@ -31,8 +31,10 @@ class SetMaterialValueCommand extends Command {
 
 	execute() {
 
-		this.material[ this.attributeName ] = this.newValue;
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ] = this.newValue;
+		material.needsUpdate = true;
 
 		this.editor.signals.objectChanged.dispatch( this.object );
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
@@ -41,8 +43,10 @@ class SetMaterialValueCommand extends Command {
 
 	undo() {
 
-		this.material[ this.attributeName ] = this.oldValue;
-		this.material.needsUpdate = true;
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ] = this.oldValue;
+		material.needsUpdate = true;
 
 		this.editor.signals.objectChanged.dispatch( this.object );
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
@@ -63,6 +67,7 @@ class SetMaterialValueCommand extends Command {
 		output.attributeName = this.attributeName;
 		output.oldValue = this.oldValue;
 		output.newValue = this.newValue;
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -76,6 +81,7 @@ class SetMaterialValueCommand extends Command {
 		this.oldValue = json.oldValue;
 		this.newValue = json.newValue;
 		this.object = this.editor.objectByUuid( json.objectUuid );
+		this.materialSlot = json.materialSlot;
 
 	}
 

editor/js/commands/SetMaterialVectorCommand.js

@@ -2,7 +2,7 @@ import { Command } from '../Command.js';
 
 class SetMaterialVectorCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue, materialSlot ) {
+	constructor( editor, object = null, attributeName = '', newValue = null, materialSlot = - 1 ) {
 
 		super( editor );
 
@@ -13,9 +13,9 @@ class SetMaterialVectorCommand extends Command {
 		this.object = object;
 		this.materialSlot = materialSlot;
 
-		this.material = this.editor.getObjectMaterial( object, materialSlot );
+		const material = ( object !== null ) ? editor.getObjectMaterial( object, materialSlot ) : null;
 
-		this.oldValue = ( this.material !== undefined ) ? this.material[ attributeName ].toArray() : undefined;
+		this.oldValue = ( material !== null ) ? material[ attributeName ].toArray() : null;
 		this.newValue = newValue;
 
 		this.attributeName = attributeName;
@@ -24,7 +24,9 @@ class SetMaterialVectorCommand extends Command {
 
 	execute() {
 
-		this.material[ this.attributeName ].fromArray( this.newValue );
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ].fromArray( this.newValue );
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -32,7 +34,9 @@ class SetMaterialVectorCommand extends Command {
 
 	undo() {
 
-		this.material[ this.attributeName ].fromArray( this.oldValue );
+		const material = this.editor.getObjectMaterial( this.object, this.materialSlot );
+
+		material[ this.attributeName ].fromArray( this.oldValue );
 
 		this.editor.signals.materialChanged.dispatch( this.object, this.materialSlot );
 
@@ -52,6 +56,7 @@ class SetMaterialVectorCommand extends Command {
 		output.attributeName = this.attributeName;
 		output.oldValue = this.oldValue;
 		output.newValue = this.newValue;
+		output.materialSlot = this.materialSlot;
 
 		return output;
 
@@ -65,6 +70,7 @@ class SetMaterialVectorCommand extends Command {
 		this.attributeName = json.attributeName;
 		this.oldValue = json.oldValue;
 		this.newValue = json.newValue;
+		this.materialSlot = json.materialSlot;
 
 	}
 

editor/js/commands/SetPositionCommand.js

@@ -10,7 +10,7 @@ import { Vector3 } from 'three';
  */
 class SetPositionCommand extends Command {
 
-	constructor( editor, object, newPosition, optionalOldPosition ) {
+	constructor( editor, object = null, newPosition = null, optionalOldPosition = null ) {
 
 		super( editor );
 
@@ -20,14 +20,14 @@ class SetPositionCommand extends Command {
 
 		this.object = object;
 
-		if ( object !== undefined && newPosition !== undefined ) {
+		if ( object !== null && newPosition !== null ) {
 
 			this.oldPosition = object.position.clone();
 			this.newPosition = newPosition.clone();
 
 		}
 
-		if ( optionalOldPosition !== undefined ) {
+		if ( optionalOldPosition !== null ) {
 
 			this.oldPosition = optionalOldPosition.clone();
 

editor/js/commands/SetRotationCommand.js

@@ -10,7 +10,7 @@ import { Euler } from 'three';
  */
 class SetRotationCommand extends Command {
 
-	constructor( editor, object, newRotation, optionalOldRotation ) {
+	constructor( editor, object = null, newRotation = null, optionalOldRotation = null ) {
 
 		super( editor );
 
@@ -20,14 +20,14 @@ class SetRotationCommand extends Command {
 
 		this.object = object;
 
-		if ( object !== undefined && newRotation !== undefined ) {
+		if ( object !== null && newRotation !== null ) {
 
 			this.oldRotation = object.rotation.clone();
 			this.newRotation = newRotation.clone();
 
 		}
 
-		if ( optionalOldRotation !== undefined ) {
+		if ( optionalOldRotation !== null ) {
 
 			this.oldRotation = optionalOldRotation.clone();
 

editor/js/commands/SetScaleCommand.js

@@ -10,7 +10,7 @@ import { Vector3 } from 'three';
  */
 class SetScaleCommand extends Command {
 
-	constructor( editor, object, newScale, optionalOldScale ) {
+	constructor( editor, object = null, newScale = null, optionalOldScale = null ) {
 
 		super( editor );
 
@@ -20,14 +20,14 @@ class SetScaleCommand extends Command {
 
 		this.object = object;
 
-		if ( object !== undefined && newScale !== undefined ) {
+		if ( object !== null && newScale !== null ) {
 
 			this.oldScale = object.scale.clone();
 			this.newScale = newScale.clone();
 
 		}
 
-		if ( optionalOldScale !== undefined ) {
+		if ( optionalOldScale !== null ) {
 
 			this.oldScale = optionalOldScale.clone();
 

editor/js/commands/SetSceneCommand.js

@@ -10,7 +10,7 @@ import { AddObjectCommand } from './AddObjectCommand.js';
  */
 class SetSceneCommand extends Command {
 
-	constructor( editor, scene ) {
+	constructor( editor, scene = null ) {
 
 		super( editor );
 
@@ -19,7 +19,7 @@ class SetSceneCommand extends Command {
 
 		this.cmdArray = [];
 
-		if ( scene !== undefined ) {
+		if ( scene !== null ) {
 
 			this.cmdArray.push( new SetUuidCommand( this.editor, this.editor.scene, scene.uuid ) );
 			this.cmdArray.push( new SetValueCommand( this.editor, this.editor.scene, 'name', scene.name ) );

editor/js/commands/SetScriptValueCommand.js

@@ -10,7 +10,7 @@ import { Command } from '../Command.js';
  */
 class SetScriptValueCommand extends Command {
 
-	constructor( editor, object, script, attributeName, newValue ) {
+	constructor( editor, object = null, script = '', attributeName = '', newValue = null ) {
 
 		super( editor );
 
@@ -22,7 +22,7 @@ class SetScriptValueCommand extends Command {
 		this.script = script;
 
 		this.attributeName = attributeName;
-		this.oldValue = ( script !== undefined ) ? script[ this.attributeName ] : undefined;
+		this.oldValue = ( script !== '' ) ? script[ this.attributeName ] : null;
 		this.newValue = newValue;
 
 	}

editor/js/commands/SetUuidCommand.js

@@ -8,7 +8,7 @@ import { Command } from '../Command.js';
  */
 class SetUuidCommand extends Command {
 
-	constructor( editor, object, newUuid ) {
+	constructor( editor, object = null, newUuid = null ) {
 
 		super( editor );
 
@@ -17,7 +17,7 @@ class SetUuidCommand extends Command {
 
 		this.object = object;
 
-		this.oldUuid = ( object !== undefined ) ? object.uuid : undefined;
+		this.oldUuid = ( object !== null ) ? object.uuid : null;
 		this.newUuid = newUuid;
 
 	}

editor/js/commands/SetValueCommand.js

@@ -9,7 +9,7 @@ import { Command } from '../Command.js';
  */
 class SetValueCommand extends Command {
 
-	constructor( editor, object, attributeName, newValue ) {
+	constructor( editor, object = null, attributeName = '', newValue = null ) {
 
 		super( editor );
 
@@ -19,7 +19,7 @@ class SetValueCommand extends Command {
 
 		this.object = object;
 		this.attributeName = attributeName;
-		this.oldValue = ( object !== undefined ) ? object[ attributeName ] : undefined;
+		this.oldValue = ( object !== null ) ? object[ attributeName ] : null;
 		this.newValue = newValue;
 
 	}