[vtkusers] Showing tissues (Skins , Vesseles) Bones just having turned the mouse wheel: Help please

[wassim_belhadj at topnet.tn]

Hi,

I' am using VTK 5.0.2.

I want to make a separation between Bones, Tissues, Vesselses ...

For this, I used a scalar Opacity transfer function  and  a Gradient
opacity transfer function.

I saw a clip védeo of Osirix(
http://www.osirix-viewer.com/Assal-OsiriX.mov ) between the 2:40 and 2:56
minutes, it shows the tissues (Skins
,Vesseles)  just having turned the mouse wheel. (Bones -> tissues).

It was so rapid !!!!

How can I do this without  rendering the  voulme another time and setting
the "vtkVolumeRayCastMapper"  properties.

My code looks like this:

/**********************************************************************************************/
/**********************************************************************************************/


switch(indx)
{
case Bones:

     tfun->AddPoint(0, 0.0);
     .......
     tfun->AddPoint(4095, 1.0);

     gtfun->AddPoint(0, 0.0);
     ....
     gtfun->AddPoint(4095, 1.0);

     break;


case RedVessels :
    ....
    break;

  .....

	vlmPrprt->SetColor(ctfun);
	vlmPrprt->SetScalarOpacity(tfun);

	 .....
	//SET the vtkVolumeRayCastMapper
	......

	iren->Render();

 }
/**********************************************************************************************/
/**********************************************************************************************/


I am on a trouble and i need your help and advice.

Thank you

Regards.