[vtkusers] OPacity issues

[James C. Robinson]

Mathieu,

I am really struggling, probably because I have come in as a high level user
(and am not too interested in the pure graphics itself). I have adapted my
code to v4.4 and it is behaving even worse. I have created a webpage
(http://www.iol.ie/~jcrobinson/opacity%20bug.htm ) showing the difference in
behaviour between v4.2 & v4.4. The issue this time is in regard opacity. I
have written my code to allow the user to set the opacity of the
visualisation objects. I do this using:
  (pMeshMaterialActor->GetProperty())->SetOpacity(factor) ;

Where pMeshMaterialActor is a vtkActor* and factor is a vtkFloatingPointType
(range 0.0 - 1.0).

The webpage shows that this doesn't work any longer.


Aside: I am suffering from my ignorance also of real software engineering. I
notice that the VTK documentation refers to vtkActor as an abstract class.
Surely this means that I shouldn't be able to have instances of these.
Should I use vtkOpenGLActor instead (I am developing for the PC, Windows
platform exclusively)? I know that I haven't been 100% satisfied with the
rendered images since I change from v3.2. It could be related some basic
choices, settings of which I am not aware.

Regards,

Jim


______________________

James C. Robinson, PhD,
Chartered Engineer,
Kepler Simulation Systems Ltd.,
42 Rivergrove,
Glanmire, Co. Cork,
Eire

Tel:         +353-21-4822028
Tel:         +353-87-2393010
Fax:        +353-21-4822028
E-mail:     j.robinson at kepler-systems.com
______________________