Reads the 3ds file and adds the 3d objects (as MeshGeometry3D, Lights, Materials) to Viewport3D If cameraIndex >= 0 than also sets the camera (if there is one in 3ds file) to Viewport3D

public Model3DGroup ReadFile(
	string fileName,
	Viewport3D viewport,
	int cameraIndex
)

Public Function ReadFile ( _
	fileName As String, _
	viewport As Viewport3D, _
	cameraIndex As Integer _
) As Model3DGroup

public:
Model3DGroup^ ReadFile(
	String^ fileName, 
	Viewport3D^ viewport, 
	int cameraIndex
)