Hi @igor.barcelosC54YD ,
Please take a look at this below code
Document doc = Autodesk.Navisworks.Api.Application.ActiveDocument;
Autodesk.Navisworks.Api.View view = doc.ActiveView;
string getRedLines = view.GetRedlines();
// The value of "getRedLines" will resemble the value I've set in the "s" variable.
// By adjusting the value of "s", you can customize your own set of red lines.
string s = "{\"Type\":\"RedlineCollection\",\"Version\":1,\"Values\":[{\"Type\":\"RedlineEllipse\",\"Version\":1,\"Thickness\":3,\"Color\":[1,0,0],\"MinPoint\":[-0.45388908606868772,0.3369782608691772],\"MaxPoint\":[0.54593652310359631,-0.2248285099990586]}]}";
view.TrySetRedlines(s);
Naveen Kumar T
Developer Technical Services
Autodesk Developer Network