From 4e7acc4be8d03111b1c1245f263b1b8f5328b761 Mon Sep 17 00:00:00 2001
From: Aras Pranckevicius <aras@nesnausk.org>
Date: Sat, 24 May 2025 15:22:19 +0200
Subject: [PATCH] Fix #138834: FBX import improved pivot handling

This does not fully fix the issue (pivots are still not handled
correctly when an object contains negative scale -- filed upstream
ufbx issue https://github.com/ufbx/ufbx/issues/218), but for regular
cases the pivots are in much better places now.

Pull Request: https://projects.blender.org/blender/blender/pulls/139381
---
 source/blender/io/fbx/importer/fbx_import.cc  |  2 +
 .../files/io_tests/fbx/issue138834_pivots.fbx |  3 +
 .../fbx/reference/issue138834_pivots.txt      | 76 +++++++++++++++++++
 .../ufbx_motionbuilder_pivot_7700a.txt        | 55 ++++++++++++++
 .../fbx/ufbx_motionbuilder_pivot_7700a.fbx    |  3 +
 5 files changed, 139 insertions(+)
 create mode 100644 tests/files/io_tests/fbx/issue138834_pivots.fbx
 create mode 100644 tests/files/io_tests/fbx/reference/issue138834_pivots.txt
 create mode 100644 tests/files/io_tests/fbx/reference/ufbx_motionbuilder_pivot_7700a.txt
 create mode 100644 tests/files/io_tests/fbx/ufbx_motionbuilder_pivot_7700a.fbx

diff --git a/source/blender/io/fbx/importer/fbx_import.cc b/source/blender/io/fbx/importer/fbx_import.cc
index 80572d73eb4..4ada3e4beff 100644
--- a/source/blender/io/fbx/importer/fbx_import.cc
+++ b/source/blender/io/fbx/importer/fbx_import.cc
@@ -343,6 +343,8 @@ void importer_main(Main *bmain, Scene *scene, ViewLayer *view_layer, const FBXIm
    * cause armatures/skins to not import correctly, when inserted in the middle of bone chain. */
   opts.geometry_transform_handling = UFBX_GEOMETRY_TRANSFORM_HANDLING_MODIFY_GEOMETRY_NO_FALLBACK;
 
+  opts.pivot_handling = UFBX_PIVOT_HANDLING_ADJUST_TO_PIVOT;
+
   opts.space_conversion = UFBX_SPACE_CONVERSION_ADJUST_TRANSFORMS;
   opts.target_axes.right = UFBX_COORDINATE_AXIS_POSITIVE_X;
   opts.target_axes.up = UFBX_COORDINATE_AXIS_POSITIVE_Z;
diff --git a/tests/files/io_tests/fbx/issue138834_pivots.fbx b/tests/files/io_tests/fbx/issue138834_pivots.fbx
new file mode 100644
index 00000000000..2067273fd92
--- /dev/null
+++ b/tests/files/io_tests/fbx/issue138834_pivots.fbx
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b6b61d87ad4e627a383a4af1ff73f5bcf1b9b5c34b39185005542b79c94294d3
+size 25584
diff --git a/tests/files/io_tests/fbx/reference/issue138834_pivots.txt b/tests/files/io_tests/fbx/reference/issue138834_pivots.txt
new file mode 100644
index 00000000000..81df96d144f
--- /dev/null
+++ b/tests/files/io_tests/fbx/reference/issue138834_pivots.txt
@@ -0,0 +1,76 @@
+==== Meshes: 4
+- Mesh 'Mesh' vtx:86 face:67 loop:300 edge:159
+    - 2 0 1 3 6 ... 36 16 17 41 40 
+    - 2/3 0/2 0/1 1/3 4/6 ... 81/85 13/37 12/36 17/41 16/40 
+  - attr 'position' FLOAT_VECTOR POINT
+    - (94.377, 9.507, 3.486)
+    - (8.077, 9.507, 3.486)
+    - (94.377, 213.684, 3.486)
+      ...
+    - (93.954, 158.336, 9.005)
+    - (97.952, 159.099, 8.925)
+    - (100.487, 156.998, 9.133)
+
+- Mesh 'Mesh.001' vtx:86 face:67 loop:300 edge:159
+    - 2 3 1 0 6 ... 16 16 40 41 17 
+    - 0/2 2/3 1/3 0/1 6/7 ... 81/85 13/37 12/36 17/41 16/40 
+  - attr 'position' FLOAT_VECTOR POINT
+    - (-94.377, 9.507, 3.486)
+    - (-8.077, 9.507, 3.486)
+    - (-94.377, 213.684, 3.486)
+      ...
+    - (-93.954, 158.336, 9.005)
+    - (-97.952, 159.099, 8.925)
+    - (-100.487, 156.998, 9.133)
+
+- Mesh 'Mesh.002' vtx:86 face:67 loop:300 edge:159
+    - 2 0 1 3 6 ... 36 16 17 41 40 
+    - 2/3 0/2 0/1 1/3 4/6 ... 81/85 13/37 12/36 17/41 16/40 
+  - attr 'position' FLOAT_VECTOR POINT
+    - (541.521, 28.042, -164.886)
+    - (455.221, 28.042, -164.886)
+    - (541.521, 232.219, -164.886)
+      ...
+    - (541.098, 176.871, -159.367)
+    - (545.096, 177.634, -159.447)
+    - (547.631, 175.533, -159.239)
+
+- Mesh 'Mesh.003' vtx:52 face:44 loop:176 edge:92
+    - 2 0 1 3 6 ... 50 28 30 48 51 
+    - 2/3 0/2 0/1 1/3 4/6 ... 26/47 30/48 42/49 41/50 28/51 
+  - attr 'position' FLOAT_VECTOR POINT
+    - (-10.789, 100.289, -4.808)
+    - (-91.753, 100.289, -4.808)
+    - (-10.789, 211.997, -4.808)
+      ...
+    - (-66.088, 88.947, 5.940)
+    - (-66.088, 93.392, 5.940)
+    - (-66.088, 93.392, 10.185)
+
+==== Objects: 5
+- Obj '01' EMPTY
+  - pos 0.000, 0.000, 0.000
+  - rot 1.571, 0.000, 0.000 (XYZ)
+  - scl 0.010, 0.010, 0.010
+  - props: str:currentUVSet='map1'
+- Obj 'Door_01' MESH data:'Mesh' par:'01'
+  - pos -102.530, 18.535, 136.567
+  - rot 0.000, 0.000, 0.000 (XYZ)
+  - scl 1.000, 1.000, 1.000
+  - props: str:currentUVSet='map1'
+- Obj 'Door_02' MESH data:'Mesh.001' par:'01'
+  - pos 102.530, 18.535, 136.567
+  - rot 0.000, 0.000, 0.000 (XYZ)
+  - scl 1.000, 1.000, 1.000
+  - props: str:currentUVSet='map1'
+- Obj 'Door_03' MESH data:'Mesh.002' par:'01'
+  - pos 710.133, 300.000, 305.051
+  - rot 3.142, 0.000, 0.000 (XYZ)
+  - scl -1.000, -1.000, -1.000
+  - props: str:currentUVSet='map1'
+- Obj 'Door_04' MESH data:'Mesh.003' par:'01'
+  - pos 203.475, 18.535, -332.622
+  - rot 0.000, 0.000, 0.000 (XYZ)
+  - scl 1.000, 1.000, 1.000
+  - props: str:currentUVSet='map1'
+
diff --git a/tests/files/io_tests/fbx/reference/ufbx_motionbuilder_pivot_7700a.txt b/tests/files/io_tests/fbx/reference/ufbx_motionbuilder_pivot_7700a.txt
new file mode 100644
index 00000000000..9a5c34a3c20
--- /dev/null
+++ b/tests/files/io_tests/fbx/reference/ufbx_motionbuilder_pivot_7700a.txt
@@ -0,0 +1,55 @@
+==== Meshes: 1
+- Mesh 'Mesh' vtx:8 face:6 loop:24 edge:12
+    - 0 1 3 2 2 ... 3 6 0 2 4 
+    - 0/2 0/1 1/3 2/3 2/4 ... 4/6 5/7 6/7 0/6 1/7 
+  - attr 'position' FLOAT_VECTOR POINT
+    - (-4.183, 1.500, 3.683)
+    - (-3.317, 1.500, 3.183)
+    - (-4.183, 2.500, 3.683)
+      ...
+    - (-3.817, 2.500, 2.317)
+    - (-4.683, 1.500, 2.817)
+    - (-3.817, 1.500, 2.317)
+  - attr 'sharp_edge' BOOLEAN EDGE
+    - 1 1 1 1 1 ... 1 1 1 1 1 
+  - attr 'material_index' INT FACE
+    - 0 0 0 0 0 0 
+  - attr 'custom_normal' INT16_2D CORNER
+    - (0, 0)
+    - (0, 0)
+    - (0, 0)
+      ...
+    - (0, 0)
+    - (0, 0)
+    - (0, 0)
+  - attr 'map1' FLOAT2 CORNER
+    - (0.375, 0.000)
+    - (0.625, 0.000)
+    - (0.625, 0.250)
+      ...
+    - (0.375, 0.000)
+    - (0.375, 0.250)
+    - (0.125, 0.250)
+  - 1 materials
+    - 'lambert1' 
+
+==== Objects: 1
+- Obj 'pCube1' MESH data:'Mesh'
+  - pos 0.050, 0.000, 0.000
+  - rot 1.571, 0.000, -0.785 (XYZ)
+  - scl 0.010, 0.010, 0.010
+
+==== Materials: 1
+- Mat 'lambert1'
+  - base color (0.500, 0.500, 0.500)
+  - specular ior 0.500
+  - specular tint (1.000, 1.000, 1.000)
+  - roughness 0.500
+  - metallic 0.000
+  - ior 1.500
+  - viewport diffuse (0.500, 0.500, 0.500, 1.000)
+  - viewport specular (1.000, 1.000, 1.000), intensity 0.500
+  - viewport metallic 0.000, roughness 0.500
+  - backface False probe True shadow False
+  - props: f3:Ambient=(0.000, 0.000, 0.000) f3:Diffuse=(0.400, 0.400, 0.400) f3:Emissive=(0.000, 0.000, 0.000) fl:Opacity=1.000
+
diff --git a/tests/files/io_tests/fbx/ufbx_motionbuilder_pivot_7700a.fbx b/tests/files/io_tests/fbx/ufbx_motionbuilder_pivot_7700a.fbx
new file mode 100644
index 00000000000..517859b688d
--- /dev/null
+++ b/tests/files/io_tests/fbx/ufbx_motionbuilder_pivot_7700a.fbx
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ce1b6168a4ad4d1b360df9271e95bc565315175b00c966ba7c6dcd11c09520bf
+size 38612