+BBTK_CATEGORY("actor");
+
+BBTK_INPUT(VolumeRendering,In0,"Image to create the volume rendering",vtkImageData*,"");
+BBTK_INPUT(VolumeRendering,In1,"Image to create the volume rendering",vtkImageData*,"");
+BBTK_INPUT(VolumeRendering,In2,"Image to create the volume rendering",vtkImageData*,"");
+BBTK_INPUT(VolumeRendering,In3,"Image to create the volume rendering",vtkImageData*,"");
+BBTK_INPUT(VolumeRendering,Renderer,"Renderer",vtkRenderer*,"");
+BBTK_OUTPUT(VolumeRendering,Out0,"Output resulting image",vtkImageData*,"");
+BBTK_OUTPUT(VolumeRendering,Out1,"Output resulting image",vtkImageData*,"");
+BBTK_OUTPUT(VolumeRendering,Out2,"Output resulting image",vtkImageData*,"");
+BBTK_OUTPUT(VolumeRendering,Out3,"Output resulting image",vtkImageData*,"");
+
+
+//BBTK_OUTPUT(VolumeRendering,Out,"Prop3D resulting from the volume rendering",vtkProp3D*,"");
+
+/*BBTK_INPUT(VolumeRendering,GreyLevel,"Greylevel related to the transparency",std::vector<double>,"");
+ BBTK_INPUT(VolumeRendering,Value,"Value of the transparency in the transfer function",std::vector<double>,"");
+ BBTK_INPUT(VolumeRendering,GreyLevelColors,"Grey level of the color in the transfer function",std::vector<double>,"");
+ BBTK_INPUT(VolumeRendering,Red,"Red value according to the GreyLevelColors",std::vector<double>,"");
+ BBTK_INPUT(VolumeRendering,Green,"Green value according to the GreyLevelColors",std::vector<double>,"");
+ BBTK_INPUT(VolumeRendering,Blue,"Blue value according to the GreyLevelColors",std::vector<double>,"");*/