package require -exact vtkrendering 5.0 if {[info commands ::vtk::init::require_package] != ""} { if {[::vtk::init::require_package vtkVolumeRenderingTCL 5.0]} { package provide vtkvolumerendering 5.0 } } else { if {[info commands vtkEncodedGradientShader] != "" || [::vtk::load_component vtkVolumeRenderingTCL] == ""} { package provide vtkvolumerendering 5.0 } }