glTF importer/exporter: fix ortho camera fram import/export

io_scene_gltf2/__init__.py

@@ -4,7 +4,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (3, 4, 38),
+    "version": (3, 4, 39),
     'blender': (3, 3, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',

io_scene_gltf2/blender/exp/gltf2_blender_gather_cameras.py

@@ -58,8 +58,16 @@ def __gather_orthographic(blender_camera, export_settings):
             znear=None
         )
 
-        orthographic.xmag = blender_camera.ortho_scale
-        orthographic.ymag = blender_camera.ortho_scale
+        _render = bpy.context.scene.render
+        scene_x = _render.resolution_x * _render.pixel_aspect_x
+        scene_y = _render.resolution_y * _render.pixel_aspect_y
+        scene_square = max(scene_x, scene_y)
+        del _render
+
+        # `Camera().ortho_scale` (and also FOV FTR) maps to the maximum of either image width or image height— This is the box that gets shown from camera view with the checkbox `.show_sensor = True`.
+
+        orthographic.xmag = blender_camera.ortho_scale * (scene_x / scene_square) / 2
+        orthographic.ymag = blender_camera.ortho_scale * (scene_y / scene_square) / 2
 
         orthographic.znear = blender_camera.clip_start
         orthographic.zfar = blender_camera.clip_end
@@ -79,9 +87,11 @@ def __gather_perspective(blender_camera, export_settings):
             znear=None
         )
 
-        width = bpy.context.scene.render.pixel_aspect_x * bpy.context.scene.render.resolution_x
-        height = bpy.context.scene.render.pixel_aspect_y * bpy.context.scene.render.resolution_y
+        _render = bpy.context.scene.render
+        width = _render.pixel_aspect_x * _render.resolution_x
+        height = _render.pixel_aspect_y * _render.resolution_y
         perspective.aspect_ratio = width / height
+        del _render
 
         if width >= height:
             if blender_camera.sensor_fit != 'VERTICAL':

io_scene_gltf2/blender/imp/gltf2_blender_camera.py

@@ -28,7 +28,7 @@ class BlenderCamera():
         if pycamera.type == "orthographic":
             cam.type = "ORTHO"
 
-            # TODO: xmag/ymag
+            cam.ortho_scale = max(pycamera.orthographic.xmag, pycamera.orthographic.ymag) * 2
 
             cam.clip_start = pycamera.orthographic.znear
             cam.clip_end = pycamera.orthographic.zfar