   how moves the mesh??
  there are many mesh .and how can i move only one?   
  DirectX has three projections: WORLD, VIEW and PROJECTION. You set up the PROJECTION in the beginning to get the near/far clipping and camera field of view; you set VIEW also in the beginning to position/rotate the camera in the world; then you set the WORLD transform for each mesh instance you draw to draw that instance in various positions/orientations.   ;  As mentioned by hplus0603,You basically have a world transformation matrix for each mesh and this transformation places the mesh in the world. So you can follow a simple pattern1) Set World Transformation Matrix2) Render Mesh3) Set World Transformation Matrix4) Render 2nd Mesh... and so forth.example c++pDevice->SetTransform(D3DTS_WORLD, &matWorld);pMesh->DrawSubset(0);example C#Device.Transform.World = matWorld;mesh.DrawSubset(i);I hope this helps.Take care.   ;  thank you very much!this's so easy!hehe   