为什么我的网格没有出现？

Question

I'm creating an application with Delphi Seattle with FMX, and I'm working with creating meshes directly myself. What I don't understand is why this mesh doesn't appear:

Mesh.Data.VertexBuffer.Length := 4;
Mesh.Data.IndexBuffer.Length := 6;

with Mesh.Data.VertexBuffer do
begin
    Vertices[0] := TPoint3D.Create( 1,  1, 0);
    Vertices[1] := TPoint3D.Create( 1, -1, 0);
    Vertices[2] := TPoint3D.Create(-1, -1, 0);
    Vertices[3] := TPoint3D.Create(-1,  1, 0);

    TexCoord0[0] := TPointF.Create(0, 1);
    TexCoord0[1] := TPointF.Create(0, 1);
    TexCoord0[2] := TPointF.Create(0, 1);
    TexCoord0[3] := TPointF.Create(0, 1);
end;

with Mesh.Data.IndexBuffer do
begin
    Indices[0] := 0;
    Indices[1] := 1;
    Indices[2] := 2;

    Indices[3] := 2;
    Indices[4] := 3;
    Indices[5] := 0;
end;

The mesh has a colour material however when I run it, the mesh does not appear. Everything else does (a cube and a grid).

Answer 1

The answer is to set the mesh to TwoSide true, then I can see it. I did try rotating the object, but still couldn't see anything.