need to perform string parsing and formatting without depending on notation. (#7)

- https://github.com/ikpil/DotRecast/issues/7
- thank you @BasicCPPDev

src/DotRecast.Recast/ObjImporter.cs

@@ -18,6 +18,7 @@ freely, subject to the following restrictions:
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using DotRecast.Recast.Geom;
 
@@ -85,7 +86,13 @@ namespace DotRecast.Recast
                 throw new Exception("Invalid vector, expected 3 coordinates, found " + (v.Length - 1));
             }
 
-            return new float[] { float.Parse(v[1]), float.Parse(v[2]), float.Parse(v[3]) };
+            // fix - https://github.com/ikpil/DotRecast/issues/7
+            return new float[]
+            {
+                float.Parse(v[1], CultureInfo.InvariantCulture), 
+                float.Parse(v[2], CultureInfo.InvariantCulture), 
+                float.Parse(v[3], CultureInfo.InvariantCulture)
+            };
         }
 
         private static void ReadFace(string line, ObjImporterContext context)