Fixed smart volume mapper crashes because of gradient opacity
Fixed smart volume mapper crashes because of gradient opacity

Change-Id: Iea8c3f44371b0d62cc87063df138014c88c57c70

ashray/VTK-EVM,ashray/VTK-EVM,sankhesh/VTK,ashray/VTK-EVM,sumedhasingla/VTK,sumedhasingla/VTK,candy7393/VTK,demarle/VTK,candy7393/VTK,SimVascular/VTK,demarle/VTK,demarle/VTK,msmolens/VTK,hendradarwin/VTK,sankhesh/VTK,demarle/VTK,keithroe/vtkoptix,gram526/VTK,candy7393/VTK,mspark93/VTK,sankhesh/VTK,johnkit/vtk-dev,SimVascular/VTK,gram526/VTK,sumedhasingla/VTK,johnkit/vtk-dev,johnkit/vtk-dev,johnkit/vtk-dev,mspark93/VTK,msmolens/VTK,jmerkow/VTK,ashray/VTK-EVM,johnkit/vtk-dev,sankhesh/VTK,candy7393/VTK,jmerkow/VTK,sumedhasingla/VTK,SimVascular/VTK,mspark93/VTK,ashray/VTK-EVM,jmerkow/VTK,keithroe/vtkoptix,msmolens/VTK,demarle/VTK,keithroe/vtkoptix,johnkit/vtk-dev,candy7393/VTK,gram526/VTK,gram526/VTK,keithroe/vtkoptix,demarle/VTK,candy7393/VTK,sumedhasingla/VTK,sankhesh/VTK,sumedhasingla/VTK,sankhesh/VTK,msmolens/VTK,mspark93/VTK,mspark93/VTK,msmolens/VTK,SimVascular/VTK,jmerkow/VTK,keithroe/vtkoptix,mspark93/VTK,gram526/VTK,candy7393/VTK,candy7393/VTK,mspark93/VTK,sankhesh/VTK,sumedhasingla/VTK,hendradarwin/VTK,msmolens/VTK,demarle/VTK,msmolens/VTK,keithroe/vtkoptix,gram526/VTK,mspark93/VTK,jmerkow/VTK,sumedhasingla/VTK,msmolens/VTK,SimVascular/VTK,jmerkow/VTK,ashray/VTK-EVM,gram526/VTK,hendradarwin/VTK,jmerkow/VTK,hendradarwin/VTK,sankhesh/VTK,jmerkow/VTK,SimVascular/VTK,ashray/VTK-EVM,keithroe/vtkoptix,ashray/VTK-EVM,gram526/VTK,hendradarwin/VTK,hendradarwin/VTK,johnkit/vtk-dev,demarle/VTK,hendradarwin/VTK,SimVascular/VTK,SimVascular/VTK,keithroe/vtkoptix