BUG:Fixed crash due to internal mappers not finding the correct scalars

The problem was that the smart mapper was not passing the proper
scalar information to the internal mappers

Change-Id: I6c6979b71bb4ad8e39c9ef843955117ba27822e6

VolumeRendering/vtkSmartVolumeMapper.cxx

@@ -375,6 +375,15 @@ void vtkSmartVolumeMapper::ComputeRenderMode(vtkRenderer *ren, vtkVolume *vol)
     {
     // We are rendering with the vtkFixedPointVolumeRayCastMapper
     case vtkSmartVolumeMapper::RayCastRenderMode:
+      if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_NAME)
+        {
+        this->RayCastMapper->SelectScalarArray(this->ArrayName);
+        }
+      else if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_ID)
+        {
+        this->RayCastMapper->SelectScalarArray(this->ArrayId);
+        }
+      this->RayCastMapper->SetScalarMode(this->GetScalarMode());
       this->ConnectMapperInput(this->RayCastMapper);
       this->RayCastMapper->SetClippingPlanes(this->GetClippingPlanes());
       this->RayCastMapper->SetCropping(this->GetCropping());
@@ -389,6 +398,15 @@ void vtkSmartVolumeMapper::ComputeRenderMode(vtkRenderer *ren, vtkVolume *vol)
 
       // We are rendering with the vtkVolumeTextureMapper3D
     case vtkSmartVolumeMapper::TextureRenderMode:
+      if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_NAME)
+        {
+        this->TextureMapper->SelectScalarArray(this->ArrayName);
+        }
+      else if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_ID)
+        {
+        this->TextureMapper->SelectScalarArray(this->ArrayId);
+        }
+      this->TextureMapper->SetScalarMode(this->GetScalarMode());
       this->ConnectMapperInput(this->TextureMapper);
       if ( this->RequestedRenderMode == vtkSmartVolumeMapper::DefaultRenderMode ||
            this->RequestedRenderMode == vtkSmartVolumeMapper::RayCastAndTextureRenderMode )
@@ -410,6 +428,15 @@ void vtkSmartVolumeMapper::ComputeRenderMode(vtkRenderer *ren, vtkVolume *vol)
 
       // We are rendering with the vtkGPUVolumeRayCastMapper
     case vtkSmartVolumeMapper::GPURenderMode:
+      if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_NAME)
+        {
+        this->GPUMapper->SelectScalarArray(this->ArrayName);
+        }
+      else if (this->ArrayAccessMode == VTK_GET_ARRAY_BY_ID)
+        {
+        this->GPUMapper->SelectScalarArray(this->ArrayId);
+        }
+      this->GPUMapper->SetScalarMode(this->GetScalarMode());
       this->GPUMapper->SetMaxMemoryInBytes(this->MaxMemoryInBytes);
       this->GPUMapper->SetMaxMemoryFraction(this->MaxMemoryFraction);
       this->GPUMapper->SetSampleDistance(