Ensure consistent use of mm within SG models and that SG models write VRML files using 0.1 inch units

3d-viewer/3d_cache/sg/sg_coords.cpp

@@ -223,10 +223,14 @@ bool SGCOORDS::WriteVRML( std::ofstream& aFile, bool aReuseFlag )
     std::string tmp;
     size_t n = coords.size();
     bool nline = false;
+    SGPOINT pt;
 
     for( size_t i = 0; i < n; )
     {
-        S3D::FormatPoint( tmp, coords[i] );
+        pt = coords[i];
+        // ensure VRML output has 1U = 0.1 inch as per legacy kicad expectations
+        pt.x /= 2.54;
+        S3D::FormatPoint( tmp, pt );
         aFile << tmp ;
         ++i;
 

plugins/3d/vrml/v1/vrml1_coords.cpp

@@ -163,6 +163,19 @@ bool WRL1COORDS::Read( WRLPROC& proc, WRL1BASE* aTopNode )
         return false;
     }
 
+    // assuming legacy kicad expectation of 1U = 0.1 inch,
+    // convert to mm to meet the expectations of the SG structure
+    std::vector< WRLVEC3F >::iterator sP = points.begin();
+    std::vector< WRLVEC3F >::iterator eP = points.end();
+
+    while( sP != eP )
+    {
+        sP->x *= 2.54;
+        sP->y *= 2.54;
+        sP->z *= 2.54;
+        ++sP;
+    }
+
     if( proc.Peek() == '}' )
     {
         proc.Pop();

plugins/3d/vrml/v2/vrml2_coords.cpp

@@ -173,6 +173,19 @@ bool WRL2COORDS::Read( WRLPROC& proc, WRL2BASE* aTopNode )
         return false;
     }
 
+    // assuming legacy kicad expectation of 1U = 0.1 inch,
+    // convert to mm to meet the expectations of the SG structure
+    std::vector< WRLVEC3F >::iterator sP = points.begin();
+    std::vector< WRLVEC3F >::iterator eP = points.end();
+
+    while( sP != eP )
+    {
+        sP->x *= 2.54;
+        sP->y *= 2.54;
+        sP->z *= 2.54;
+        ++sP;
+    }
+
     if( proc.Peek() == '}' )
     {
         proc.Pop();