public static void Run()
{
// ExStart:GenerateDataForMeshes
// Load a 3ds file, 3ds file doesn't have normal data, but it has smoothing group
Scene s = new Scene(RunExamples.GetDataFilePath("camera.3ds"));
// Visit all nodes and create normal data for all meshes
s.RootNode.Accept(delegate(Node n)
{
Mesh mesh = n.GetEntity <Mesh>();
if (mesh != null)
{
VertexElementNormal normals = PolygonModifier.GenerateNormal(mesh);
mesh.VertexElements.Add(normals);
}
return(true);
});
// ExEnd:GenerateDataForMeshes
Console.WriteLine("\nNormal data generated successfully for all meshes.");
}
/// <summary>
/// Build the normal data from the scene,
/// the vertex buffer stores the coordinate of the normal
/// lines in world coordinate system.
/// </summary>
/// <param name="scene"></param>
private void BuildNormals(Scene scene)
{
vecs.Clear();
scene.RootNode.Accept(delegate(Node n)
{
var mc = n.Entity as IMeshConvertible;
if (mc == null)
{
return(true);
}
SetNode(n);
var mesh = mc.ToMesh();
var ven = (VertexElementNormal)mesh.GetElement(VertexElementType.Normal);
if (ven == null)
{
ven = PolygonModifier.GenerateNormal(mesh);
}
var indirect = ven.ReferenceMode == ReferenceMode.IndexToDirect;
//The normal data is mapped by polygon
if (ven.MappingMode == MappingMode.Polygon)
{
for (int i = 0; i < ven.Data.Count; i++)
{
var polygon = mesh.Polygons[i];
var center = CalculateCenter(polygon, mesh.ControlPoints);
var idx = indirect ? ven.Indices[i] : i;
var norm = ven.Data[idx];
DrawNormal(center, norm);
}
}
//The normal data is mapped by polygon vertex
else if (ven.MappingMode == MappingMode.PolygonVertex)
{
int vtx = 0;
for (int p = 0; p < mesh.PolygonCount; p++)
{
var polygon = mesh.Polygons[p];
for (int v = 0; v < polygon.Length; v++, vtx++)
{
var idx = indirect ? ven.Indices[vtx] : vtx;
var norm = ven.Data[idx];
var center = mesh.ControlPoints[polygon[v]];
DrawNormal(center, norm);
}
}
}
//The normal data is mapped by control point
else if (ven.MappingMode == MappingMode.ControlPoint)
{
int vtx = 0;
for (int p = 0; p < mesh.ControlPoints.Count; p++)
{
var center = mesh.ControlPoints[p];
var idx = indirect ? ven.Indices[p] : p;
var norm = ven.Data[idx];
DrawNormal(center, norm);
}
}
else
{
Console.WriteLine("Unsupported mapping mode");
}
return(true);
});
normals = vecs.Count / 2;
//load the data to buffer
buffer.LoadData(vecs.ToArray());
}
