From 36ef660763a2daa60ce22be936b47ab2c8c0362e Mon Sep 17 00:00:00 2001
From: Andrej730 <azhilenkov@gmail.com>
Date: Thu, 15 Jun 2023 12:45:43 +0500
Subject: [PATCH] Added option to choose triangulation method on fbx export

---
 io_scene_fbx/__init__.py       | 24 ++++++++++++++++++++++++
 io_scene_fbx/export_fbx_bin.py |  9 +++++++--
 io_scene_fbx/fbx_utils.py      |  3 ++-
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/io_scene_fbx/__init__.py b/io_scene_fbx/__init__.py
index 0c0c15eca..78f5f61e6 100644
--- a/io_scene_fbx/__init__.py
+++ b/io_scene_fbx/__init__.py
@@ -512,6 +512,25 @@ class ExportFBX(bpy.types.Operator, ExportHelper):
             description="Convert all faces to triangles",
             default=False,
             )
+    triangulation_quad_method: EnumProperty(
+            name="Quad Method",
+            items=(('BEAUTY', "Beauty", "Split the quads in nice triangles, slower method"),
+                   ('FIXED', "Fixed", "Split the quads on the first and third vertices"),
+                   ('ALTERNATE', "Fixed Alternate", "Split the quads on the 2nd and 4th vertices"),
+                   ('SHORT_EDGE', "Shortest Diagonal", "Split the quads along their shortest diagonal"),
+                   ('LONG_EDGE', "Longest Diagonal", "Split the quads along their longest diagonal"),
+                   ),
+            description="Method for splitting the quads into triangles",
+            default='BEAUTY',
+            )
+    triangulation_ngon_method: EnumProperty(
+            name="N-gon Method",
+            items=(('BEAUTY', "Beauty", "Arrange the new triangles evenly (slow)"),
+                   ('EAR_CLIP', "Clip", "Split the polygons with an ear clipping algorithm"),
+                   ),
+            description="Method for splitting the n-gons into triangles",
+            default='BEAUTY',
+            )
     use_custom_props: BoolProperty(
             name="Custom Properties",
             description="Export custom properties",
@@ -791,6 +810,11 @@ class FBX_PT_export_geometry(bpy.types.Panel):
         #sub.prop(operator, "use_mesh_modifiers_render")
         layout.prop(operator, "use_mesh_edges")
         layout.prop(operator, "use_triangles")
+        if operator.use_triangles:
+            layout.label(text="Triangulation settings")
+            box = layout.box()
+            box.prop(operator, "triangulation_quad_method")
+            box.prop(operator, "triangulation_ngon_method")
         sub = layout.row()
         #~ sub.enabled = operator.mesh_smooth_type in {'OFF'}
         sub.prop(operator, "use_tspace")
diff --git a/io_scene_fbx/export_fbx_bin.py b/io_scene_fbx/export_fbx_bin.py
index 66cd9e691..4d671ea9e 100644
--- a/io_scene_fbx/export_fbx_bin.py
+++ b/io_scene_fbx/export_fbx_bin.py
@@ -2567,7 +2567,9 @@ def fbx_data_from_scene(scene, depsgraph, settings):
                     import bmesh
                     bm = bmesh.new()
                     bm.from_mesh(tmp_me)
-                    bmesh.ops.triangulate(bm, faces=bm.faces)
+                    bmesh.ops.triangulate(bm, faces=bm.faces, 
+                        quad_method=settings.triangulation_quad_method, 
+                        ngon_method=settings.triangulation_ngon_method)
                     bm.to_mesh(tmp_me)
                     bm.free()
                 # Usually the materials of the evaluated object will be the same, but modifiers, such as Geometry Nodes,
@@ -3294,6 +3296,8 @@ def save_single(operator, scene, depsgraph, filepath="",
                 use_mesh_edges=True,
                 use_tspace=True,
                 use_triangles=False,
+                triangulation_quad_method='BEAUTY',
+                triangulation_ngon_method='BEAUTY',
                 embed_textures=False,
                 use_custom_props=False,
                 bake_space_transform=False,
@@ -3362,7 +3366,8 @@ def save_single(operator, scene, depsgraph, filepath="",
         operator.report, (axis_up, axis_forward), global_matrix, global_scale, apply_unit_scale, unit_scale,
         bake_space_transform, global_matrix_inv, global_matrix_inv_transposed,
         context_objects, object_types, use_mesh_modifiers, use_mesh_modifiers_render,
-        mesh_smooth_type, use_subsurf, use_mesh_edges, use_tspace, use_triangles,
+        mesh_smooth_type, use_subsurf, use_mesh_edges, use_tspace, 
+        use_triangles, triangulation_quad_method, triangulation_ngon_method,
         armature_nodetype, use_armature_deform_only,
         add_leaf_bones, bone_correction_matrix, bone_correction_matrix_inv,
         bake_anim, bake_anim_use_all_bones, bake_anim_use_nla_strips, bake_anim_use_all_actions,
diff --git a/io_scene_fbx/fbx_utils.py b/io_scene_fbx/fbx_utils.py
index 3bbb342d3..1035cdc9a 100644
--- a/io_scene_fbx/fbx_utils.py
+++ b/io_scene_fbx/fbx_utils.py
@@ -1543,7 +1543,8 @@ FBXExportSettings = namedtuple("FBXExportSettings", (
     "report", "to_axes", "global_matrix", "global_scale", "apply_unit_scale", "unit_scale",
     "bake_space_transform", "global_matrix_inv", "global_matrix_inv_transposed",
     "context_objects", "object_types", "use_mesh_modifiers", "use_mesh_modifiers_render",
-    "mesh_smooth_type", "use_subsurf", "use_mesh_edges", "use_tspace", "use_triangles",
+    "mesh_smooth_type", "use_subsurf", "use_mesh_edges", "use_tspace", 
+    "use_triangles", "triangulation_quad_method", "triangulation_ngon_method",
     "armature_nodetype", "use_armature_deform_only", "add_leaf_bones",
     "bone_correction_matrix", "bone_correction_matrix_inv",
     "bake_anim", "bake_anim_use_all_bones", "bake_anim_use_nla_strips", "bake_anim_use_all_actions",
-- 
2.30.2