Data setter and simple Render.

src/src/Rendering/Viewer/VolumeRenderingViewer.cpp

@@ -160,13 +160,15 @@ void VolumeRenderingViewer::SetRenderer(vtkRenderer *arg) {
 }
 
 void VolumeRenderingViewer::Render() {
-
+    if (RenderWindow)RenderWindow->Render();
 }
 
 void VolumeRenderingViewer::SetInputData(vtkImageData *in) {
-
+    if (in && in != this->VolumeMapper->GetInput()){
+        this->VolumeMapper->SetInputData(in);
+    }
 }
 
 vtkImageData *VolumeRenderingViewer::GetInput() {
-    return nullptr;
+    return this->VolumeMapper->GetInput();
 }