Any examples of how to create a breps from raw meshes in RhinoCommon?

Rhino Developer
1

Suppose I have a vertex list:

((0, 0, 0), (1, 0, 0), (1, 1, 0), (0, 1, 0), (0, 0, 1), (1, 0, 1), (1, 1, 1), (0, 1, 1))

and a face list that indexes into the vertex list (this one for the surface of a cube with each cube face divided into triangular facets):

((1, 6, 5), (6, 7, 5), (8, 3, 4), (3, 1, 4), (1, 8, 4), (1, 3, 2), (3, 7, 2), (7, 6, 2), (6, 1, 2), (7, 3, 8), (8, 1, 5), (7, 8, 5))

Are there any examples that would hint at how to turn this into a Rhino Brep using RhinoCommon?

Chris

2

I found the answer in the examples for ObjectTable.AddMesh.

Chris

3

Here is a simple example:

protected override Result RunCommand(RhinoDoc doc, RunMode mode)
{
  double xdim = 15.0;
  double ydim = 10.0;
  double zdim = 5.0;

  Rhino.Geometry.Mesh mesh = new Rhino.Geometry.Mesh();
  mesh.Vertices.Add(0.0, 0.0, 0.0);
  mesh.Vertices.Add(xdim, 0.0, 0.0);
  mesh.Vertices.Add(xdim, ydim, 0.0);
  mesh.Vertices.Add(0.0, ydim, 0.0);
  mesh.Vertices.Add(0.0, 0.0, zdim);
  mesh.Vertices.Add(xdim, 0.0, zdim);
  mesh.Vertices.Add(xdim, ydim, zdim);
  mesh.Vertices.Add(0.0, ydim, zdim);

  mesh.Faces.AddFace(0, 1, 2, 3);
  mesh.Faces.AddFace(0, 1, 5, 4);
  mesh.Faces.AddFace(1, 2, 6, 5);
  mesh.Faces.AddFace(2, 3, 7, 6);
  mesh.Faces.AddFace(3, 0, 4, 7);
  mesh.Faces.AddFace(4, 5, 6, 7);

  mesh.Normals.ComputeNormals();
  mesh.Compact();

  Rhino.DocObjects.ObjectAttributes attribs = doc.CreateDefaultAttributes();
  attribs.Name = "Sample Mesh";

  doc.Objects.AddMesh(mesh, attribs);
  doc.Views.Redraw();

  return Result.Success;
}

What I don’t understand is why you want to create a Brep from the mesh. Can you explain?

4

At the time I thought that to get the geometry into Rhino, I had to turn it into a Brep. I didn’t know that Mesh is an alternative.

But I’m still wondering: if I have, for example, an arbitrary parametric surface and don’t want to lose resolution or efficiency by discretizing it, what’s the best way to get it into Rhino?

5

Not knowing full details, I’d tell you to create a NurbsSurface.