LDrawLoader: Fail gracefully if an object could not be loaded, update part defaults for faster loading & more robust loading (#22957)

examples/jsm/loaders/LDrawLoader.js

@@ -967,13 +967,14 @@ class LDrawLoader extends Loader {
 			mainEdgeColourCode: parentScope ? parentScope.mainEdgeColourCode : '24',
 			currentMatrix: new Matrix4(),
 			matrix: new Matrix4(),
+			type: 'Model',
 
 			// If false, it is a root material scope previous to parse
 			isFromParse: true,
 
-			faces: null,
-			lineSegments: null,
-			conditionalSegments: null,
+			faces: [],
+			lineSegments: [],
+			conditionalSegments: [],
 			totalFaces: 0,
 
 			// If true, this object is the start of a construction step
@@ -1443,9 +1444,6 @@ class LDrawLoader extends Loader {
 
 								type = lp.getToken();
 
-								currentParseScope.faces = [];
-								currentParseScope.lineSegments = [];
-								currentParseScope.conditionalSegments = [];
 								currentParseScope.type = type;
 
 								const isRoot = ! parentParseScope.isFromParse;
@@ -1856,6 +1854,13 @@ class LDrawLoader extends Loader {
 
 	finalizeObject( subobjectParseScope ) {
 
+		// fail gracefully if an object could not be loaded
+		if ( subobjectParseScope === null ) {
+
+			return;
+
+		}
+
 		const parentParseScope = subobjectParseScope.parentScope;
 
 		// Smooth the normals if this is a part or if this is a case where the subpart
@@ -2045,6 +2050,7 @@ class LDrawLoader extends Loader {
 			} ).catch( function () {
 
 				console.warn( 'LDrawLoader: Subobject "' + subobject.fileName + '" could not be found.' );
+				return null;
 
 			} );