From 8556bd45c2733eb95a4b0829a677414dcccbb732 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Thu, 17 Jul 2025 16:47:39 -0700
Subject: [PATCH] Handle model projection in Altium import

If the model is seated on the back, KiCad just needs to rotate and
offset for the board (if it is placed)

Fixes https://gitlab.com/kicad/code/kicad/-/issues/213356
---
 pcbnew/pcb_io/altium/altium_parser_pcb.cpp |  1 +
 pcbnew/pcb_io/altium/altium_pcb.cpp        | 27 ++++++++++++++++++----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/pcbnew/pcb_io/altium/altium_parser_pcb.cpp b/pcbnew/pcb_io/altium/altium_parser_pcb.cpp
index 35ed585c61..d8cc640e0c 100644
--- a/pcbnew/pcb_io/altium/altium_parser_pcb.cpp
+++ b/pcbnew/pcb_io/altium/altium_parser_pcb.cpp
@@ -702,6 +702,7 @@ ACOMPONENTBODY6::ACOMPONENTBODY6( ALTIUM_BINARY_PARSER& aReader )
     rotation = ALTIUM_PROPS_UTILS::ReadDouble( properties, wxT( "MODEL.2D.ROTATION" ), 0. );
 
     body_opacity_3d = ALTIUM_PROPS_UTILS::ReadDouble( properties, wxT( "BODYOPACITY3D" ), 1. );
+    body_projection = ALTIUM_PROPS_UTILS::ReadInt( properties, wxT( "BODYPROJECTION" ), 0 );
 
     aReader.SkipSubrecord();
 
diff --git a/pcbnew/pcb_io/altium/altium_pcb.cpp b/pcbnew/pcb_io/altium/altium_pcb.cpp
index 44ae8cf67f..5705dfb74e 100644
--- a/pcbnew/pcb_io/altium/altium_pcb.cpp
+++ b/pcbnew/pcb_io/altium/altium_pcb.cpp
@@ -1116,6 +1116,7 @@ void ALTIUM_PCB::ParseBoard6Data( const ALTIUM_PCB_COMPOUND_FILE&     aAltiumPcb
     }
 
     HelperCreateBoardOutline( elem.board_vertices );
+    m_board->GetDesignSettings().SetBoardThickness( stackup.BuildBoardThicknessFromStackup() );
 }
 
 
@@ -1450,13 +1451,21 @@ void ALTIUM_PCB::ConvertComponentBody6ToFootprintItem( const ALTIUM_PCB_COMPOUND
         orientation              = -orientation;
     }
 
+    VECTOR3D modelRotation( aElem.modelRotation );
+
+    if( aElem.body_projection == 1 )
+    {
+        modelRotation.x += 180;
+        modelRotation.z += 180;
+    }
+
     RotatePoint( &modelSettings.m_Offset.x, &modelSettings.m_Offset.y, orientation );
 
-    modelSettings.m_Rotation.x = normalizeAngleDegrees( -aElem.modelRotation.x, -180, 180 );
-    modelSettings.m_Rotation.y = normalizeAngleDegrees( -aElem.modelRotation.y, -180, 180 );
-    modelSettings.m_Rotation.z = normalizeAngleDegrees( -aElem.modelRotation.z + aElem.rotation
-                                                                               + orientation.AsDegrees(),
-                                                                                 -180, 180 );
+    modelSettings.m_Rotation.x = normalizeAngleDegrees( -modelRotation.x, -180, 180 );
+    modelSettings.m_Rotation.y = normalizeAngleDegrees( -modelRotation.y, -180, 180 );
+    modelSettings.m_Rotation.z = normalizeAngleDegrees( -modelRotation.z + aElem.rotation
+                                                                         + orientation.AsDegrees(),
+                                                                           -180, 180 );
     modelSettings.m_Opacity = aElem.body_opacity_3d;
 
     aFootprint->Models().push_back( modelSettings );
@@ -1541,6 +1550,14 @@ void ALTIUM_PCB::ParseComponentsBodies6Data( const ALTIUM_PCB_COMPOUND_FILE&
             orientation              = -orientation;
         }
 
+        if( elem.body_projection == 1 )
+        {
+            elem.modelRotation.x += 180;
+            elem.modelRotation.z += 180;
+            modelSettings.m_Offset.z =  pcbIUScale.IUTomm( m_board->GetDesignSettings().GetBoardThickness() )
+                                       + modelSettings.m_Offset.z;
+        }
+
         RotatePoint( &modelSettings.m_Offset.x, &modelSettings.m_Offset.y, orientation );
 
         modelSettings.m_Rotation.x = normalizeAngleDegrees( -elem.modelRotation.x, -180, 180 );