Recently I was working on a project and I had to use TinSurfaceTriangle object to access the Surface triangle vertices. You might be knowing already that TinSurfaceTriangle class encapsulates a triangle in a TinSurface in AutoCAD Civil 3D. TinSurfaceTriangle type exposes the following members -
Vertex1 - > Gets the first vertex in the triangle.
Vertex2 - > Gets the second vertex in the triangle.
Vertex3 - > Gets the third vertex in the triangle.
One question came up during our discussion - in which direction (clock-wise or anti-clockwise) these vertex points are counted. So, to figure out that I did a quick test to iterate through the vertices and see which direction they are returned by Civil 3D API. Here is the result which shows us the direction :
And the C# .NET code snippet I used :
using (Transaction trans = db.TransactionManager.StartTransaction())
{
TinSurface surface = trans.GetObject(surfaceId, OpenMode.ForRead) as TinSurface;
TinSurfaceTriangleCollection tinSurfTrianglColl = surface.GetTriangles(true);
if (tinSurfTrianglColl.Count > 0)
{
foreach (TinSurfaceTriangle tinsurfTriangle in tinSurfTrianglColl)
{
// Vertex1
Point3d pnt3d = tinsurfTriangle.Vertex1.Location;
ed.WriteMessage("\n Vertex1 :: X1 : " + pnt3d.X.ToString() +
" Y1 : " + pnt3d.Y.ToString() +
" Z1 : " + pnt3d.Z.ToString());
// Vertex2
pnt3d = tinsurfTriangle.Vertex2.Location;
ed.WriteMessage("\n Vertex2 :: X1 : " + pnt3d.X.ToString() +
" Y1 : " + pnt3d.Y.ToString() +
" Z1 : " + pnt3d.Z.ToString());
// Vertex3
pnt3d = tinsurfTriangle.Vertex3.Location;
ed.WriteMessage("\n Vertex3 :: X1 : " + pnt3d.X.ToString() +
" Y1 : " + pnt3d.Y.ToString() +
" Z1 : " + pnt3d.Z.ToString());
}
}
trans.Commit();
}
Hope this is useful to you!
