Hi, > I'm looking for a free vtk viewer for MS-Windows, which would support > transparency and color control of several polydata. > Thanks in advance. Did you try ParaView from Kitware ? greets Ingo --- Dr.-Ing. Ingo H. de Boer Polytec GmbH Polytec-Platz 1-7, 76337 Waldbronn, Germany phone: ++49 7243 604 106 fax : ++49 7243 604 255