Transfer Function Editor window not loading

[AuxiliaryPanther]

Accidentally closed previous issue. More information for this issue shows it as a GUI issue with the transfer function window.

Repro:

• Unity 6 (6000.0.35f1)
• Tried both UnityVolumeRendering-2020.3+ and UnityVolumeRendering-2019 (R2024.4)

1. Import DICOM files using your documentation
2. Select model in scene
3. Open Inspector
4. Note: I have to manually add the component Volume Rendered Object for each model.
5. Select any Render Mode
6. Select any Transfer Function Type
7. Click "Edit transfer function"
8. TransferFunctionEditorWindow appears completely empty for any combination of render mode and TF type.
9. Then the following two error messages appear 6 times each every second in Console, starting with the following:

ERROR 1:
NullReferenceException: Object reference not set to an instance of an object
UnityVolumeRendering.TransferFunctionEditor.DrawOnGUI (UnityEngine.Rect rect) (at Assets/UnityVolumeRendering/Assets/Scripts/GUI/IMGUI/TransferFunctionEditor.cs:64)
UnityVolumeRendering.TransferFunctionEditorWindow.OnGUI () (at Assets/UnityVolumeRendering/Assets/Editor/TransferFunctionEditorWindow.cs:66)
UnityEditor.HostView.InvokeOnGUI (UnityEngine.Rect onGUIPosition) (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEditor.DockArea.DrawView (UnityEngine.Rect dockAreaRect) (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEditor.DockArea.OldOnGUI () (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at :0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

ERROR 2:
NullReferenceException: Object reference not set to an instance of an object
UnityVolumeRendering.TransferFunctionEditor.DrawOnGUI (UnityEngine.Rect rect) (at Assets/UnityVolumeRendering/Assets/Scripts/GUI/IMGUI/TransferFunctionEditor.cs:64)
UnityVolumeRendering.TransferFunctionEditorWindow.OnGUI () (at Assets/UnityVolumeRendering/Assets/Editor/TransferFunctionEditorWindow.cs:66)
UnityEditor.HostView.InvokeOnGUI (UnityEngine.Rect onGUIPosition) (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEditor.DockArea.DrawView (UnityEngine.Rect dockAreaRect) (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEditor.DockArea.OldOnGUI () (at <2f9d421960d84dffaa88793de0f4b5f3>:0)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at :0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at :0)
UnityEngine.UIElements.IMGUIContainer.DoIMGUIRepaint () (at :0)
UnityEngine.UIElements.UIR.RenderChainCommand.ExecuteNonDrawMesh (UnityEngine.UIElements.UIR.DrawParams drawParams, System.Single pixelsPerPoint, System.Exception& immediateException) (at :0)
Rethrow as ImmediateModeException
UnityEngine.UIElements.UIR.RenderChain.Render () (at :0)
UnityEngine.UIElements.UIRRepaintUpdater.Render () (at :0)
UnityEngine.UIElements.BaseVisualElementPanel.Render () (at :0)
UnityEngine.UIElements.Panel.Render () (at :0)
UnityEditor.UIElements.EditorPanel.Render () (at <440ef95092dc402283338101458784af>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at :0)
UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at :0)
UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at :0)
UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at :0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <597a8f11f7f6488b9a0d0f6e0dc59248>:0)

[AuxiliaryPanther]

I've tried both packages of R2024.4 and UnityVolumeRendering-2020.3+ of Release 5 with Unity version 2020.3.0f1 to see if I could recreate it there, but that just caused the plugin to crash due to separate issues entirely. I don't plan on submitting a separate issue for that yet.

[mlavik1]

Hi, sorry for the late response.

Note: I have to manually add the component Volume Rendered Object for each model.

I think this may be the actual problem. Manually adding VolumeRenderedObject after importing won't work nicely.
Could you send me a screenshot of how the model looks in the scene? And if possible, it would be really helpful if you could share the model.

I've tested DICOM import in the same version of Unity, and it works fine for me (Windows and Linux).
If VolumeRenderedObject is missing from the imported model then that sounds like a symptom of import failure. I wonder if there are any relevant messages in the log? (on import, so not the "DrawOnGUI" when showing the TF editor)