Making a custom mesh in C# managed DirectX

Question

I need to make a DirectX 3D mesh at run time using Managed DirectX from C#. I have not been able to locate any information on how to do this.

1. No, I can't use a 3D modeler program to make my objects. They must be precisely sized and shaped, and I don't have ANY of the size or shape information until runtime.
2. No, I can't build up the model from existing DirectX mesh capabilities. (A simple example: DirectX would let you easily model a pencil by using a cone mesh and a cylinder mesh. Of course, you have to carry around two meshes for your pencil, not just one, and properly position and orient each. But you can not even make a model of a pencil split in half lengthwise as there is no half cylinder nor half cone mesh provided.)
3. At runtime, I have all of the vertices already computed and know which ones to connect to make the necessary triangles.
4. All I need is a solid color. I don't need to texture map.

One can get a mesh of a sphere using this DirectX call:
Mesh sphere = Mesh.Sphere(device, sphereRadius, sphereSlices, sphereStacks);
This mesh is built at runtime.

What I need to know is how to make a similar function:
Mesh shape = MakeCustomMesh(device, vertexlist, trianglelist);
where the two lists could be any suitable container/format.

If anyone can point me to managed DirectX (C#) sample code, even if it just builds a mesh from 3 hardcoded triangles, that would be a great benefit.

Answer 1

There's some sample code showing how to do this on MDXInfo. This creates a mesh with multiple subsets - if you don't need that, it's even easier.

Basically, you just create the mesh:

Mesh mesh = new Mesh(numIndices, numVerticess, MeshFlags.Managed, CustomVertex.PositionColored.Format /* you'll need to set this */ , device);

Then, you can grab the mesh vertex buffer and index buffer, and overwrite it, using:

IndexBuffer indices = mesh.IndexBuffer;
VertexBuffer vertices = mesh.VertexBuffer;

Then, fill in the indices and vertices appropriately.