RealDWG: Extracting Color Information from Solids

<?xml encoding=”UTF-8″>By Madhukar
Moogala

Using RealDWG SDK,  following code extracts the color information of 3d solids in AutoCAD drawings.

To extract color from sub elements of Solid we will use BREP api, you need to refer AcDbMgdBrep.dll module from sdk.

You can use – Testdrawing 

        private void DumpSolid3d(Transaction tr, ObjectId solId)
{
using (OpenCloseTransaction oct = new OpenCloseTransaction())
{
Solid3d solid = tr.GetObject(solId, OpenMode.ForRead) as Solid3d;
ObjectId[] ids = new ObjectId[] { solid.ObjectId };
FullSubentityPath path =
new FullSubentityPath(
ids,
new SubentityId(SubentityType.Null, IntPtr.Zero)
);
// For storing SubentityIds of cylindrical faces
List subentIds = new List();
using (Brep brep = new Brep(path))
{
foreach (Autodesk.AutoCAD.BoundaryRepresentation.Face face in brep.Faces)
{
/*
// How to get colors of only cylinderical
Autodesk.AutoCAD.Geometry.Surface surf = face.Surface;
var ebSurf = surf as Autodesk.AutoCAD.Geometry.ExternalBoundedSurface;
if (ebSurf != null && ebSurf.IsCylinder)
{
subentIds.Add(face.SubentityPath.SubentId);
}
*/
subentIds.Add(face.SubentityPath.SubentId);
}
}
if (subentIds.Count > 0)
{
List> ColorSubEntityPairs
= GetColors(solid, subentIds);
foreach (var item in ColorSubEntityPairs)
{
var color = item.Key as Color;
SubentityId id = item.Value;
Console.WriteLine($"nColor - {color.ColorNameForDisplay}
| SubEntity Index - {id.IndexPtr}");
}
}
oct.Commit();
}
}
List< KeyValuePair< Color,SubentityId >>
GetColors(Solid3d solid, List subentIds)
{
List < KeyValuePair < Color, SubentityId >> ColorSubEntityPairs
= new List< KeyValuePair >();
foreach (SubentityId subentId in subentIds)
{
try
{
Color col = solid.GetSubentityColor(subentId);
ColorSubEntityPairs.Add(new KeyValuePair(col, subentId));
}
catch (Autodesk.AutoCAD.BoundaryRepresentation.Exception ex)
{
if(ex.ErrorStatus == ErrorStatus.NotApplicable)
continue;
}
}
return ColorSubEntityPairs;
}
</keyvaluepair

Output

SolidColors.exe "C:rd2020RealDWG 2020SamplesSolidColorstestBox.dwg"
BlockTable -*Model_Space
Color - 250 | SubEntity Index - 1
Color - 250 | SubEntity Index - 2
Color - 250 | SubEntity Index - 3
Color - 250 | SubEntity Index - 4
Color - 250 | SubEntity Index - 5
Color - 250 | SubEntity Index - 6
Color - 250 | SubEntity Index - 7
Color - 50 | SubEntity Index - 8
Color - 50 | SubEntity Index - 9
Color - 50 | SubEntity Index - 10
Color - 50 | SubEntity Index - 11
Color - 50 | SubEntity Index - 12
Color - 50 | SubEntity Index - 13
BlockTable -*Paper_Space
BlockTable -*Paper_Space0

Source code