From 63940db13153be69d0da1c93d2788a12585b533a Mon Sep 17 00:00:00 2001
From: Sakai-san <o_edo@hotmail.com>
Date: Thu, 2 Oct 2025 14:29:58 +0200
Subject: [PATCH] Add support for quoted filenames in mtllib entries

- Handle quoted filenames (single or double quotes) in mtllib statements
- Support filenames with spaces when properly quoted
- Maintain backward compatibility with unquoted filenames
---
 src/OBJFile.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/OBJFile.js b/src/OBJFile.js
index f4c9e6e..b1faa56 100644
--- a/src/OBJFile.js
+++ b/src/OBJFile.js
@@ -28,7 +28,15 @@ class OBJFile {
     for (let i = 0; i < lines.length; i += 1) {
       const line = _stripComments(lines[i]);
 
-      const lineItems = line.replace(/\s+/g, ' ').trim().split(' ');
+      // splitting by blanks. For mtllib entry, balanced quote (single or double) around referreed file is stripped and file name having blanks is supported.
+      let lineItems;
+      let mtllibMatch = line.match(/^\s*(mtllib)\s+(['"]?)(.*?)\2\s*$/i);
+
+      if (mtllibMatch) {
+        lineItems = [mtllibMatch[1].toLowerCase(), mtllibMatch[3]];
+      } else {
+        lineItems = line.replace(/\s+/g, ' ').trim().split(' ');
+      }
 
       switch (lineItems[0].toLowerCase()) {
         case 'o': // Start A New Model