   directx 10 meshes and submeshes
  Hy.I create some importer from collada .The problem is that a document can contains more than on meshes and a meshes can contains more than one submesh.I have the scene graph that rappresent all the position of the imported meshes.How i render all the meshes with a shader in directx 10?How i change the position of the mesh(a matrix) and the mesh(vertexbuffer) from one node to another?I coumunicate with the shader with the constant buffer the new position and then draw in a loop?Thanks   
  I'm not sure I follow you.If you have a graph data structure with appropriate data at each node (e.g. the vertex buffer containing that subset of geometry) then you'll usually walk the graph and apply the transformations as appropriate. It's reasonably common to use a stack of transformations where you'll peek at the top matrix, multiply it by the current node's matrix and push the result on to the top and use that when rendering (e.g. set it to your shader's CB). The next step down the graph has the chain of matrices all ready and waiting...hthJack   ;  You set the world matrix for each subset, which you declare as a variable in your shader. So yes, "you communicate the position to the shader" via the world matrix.You calculate the world matrix by multiplying matrices from the root down to the subset, before you set the value to be communicated to the shader.