Hight Order Primitive

[RobyDx]

I have 2 problems:

1)I want to draw cubic bezier rectangular patch. When I draw 1 path I put vertex from left to right and up to down to create a 4 x 4 group (an array of 16 vertex). How I must order then if for example I want to create a plane of 4 x 4 patch?

2)How work patch mesh? I create one, I use tessellate applied to the normal mesh and in present it give me an error if I draw the mesh that I tessellate.

 

patchMesh.Tessellate(4, normalMesh)

normalMesh.DrawSubset(i)

 

 

Initialitation code is this

 

Dim paInfo As New PatchInformation

paInfo.BasisType = BasisType.BSpline

paInfo.PatchType = PatchType.Rectangle

paInfo.Degree = DegreeType.Cubic

paInfo.TessellateLevel = New Single() {3, 3, 3, 3}

Dim elementi() As VertexElement = {New VertexElement(0, 0, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Position, 0), New VertexElement(0, 12, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Normal, 0), New VertexElement(0, 24, DeclarationType.Float2, DeclarationMethod.Default, DeclarationUsage.TextureCoordinate, 0), VertexElement.VertexDeclarationEnd}

 

PatchMesh = New PatchMesh(device, paInfo, 4, normalMesh.NumberVertices, elementi)

 

How it works patchMesh? Anyone can help me or give me a website that cover also in C++ this topic?