# Problem in loading volume rendering automatically
**URL:** https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747
**Category:** Support
**Tags:** python, volume-rendering
**Created:** [February 2, 2022, 7:25am UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747 "2022-02-02T07:25:58Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@user5](https://discourse.slicer.org/u/user5)
#### Post date: [February 2, 2022, 7:25am UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747/1 "2022-02-02T07:25:58Z")
I would like to load the volume rendering automatically when I open the Slicer.
I follow the code in this link, but the volume rendering cannot load automatically.
[https://slicer.readthedocs.io/en/latest/developer\_guide/script\_repository.html#show-volume-rendering-automatically-when-a-volume-is-loaded](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#show-volume-rendering-automatically-when-a-volume-is-loaded)
How should I solve this error?
---
### Author:  [@ebrahim](https://discourse.slicer.org/u/ebrahim)
#### Post date: [February 2, 2022, 11:44am UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747/2 "2022-02-02T11:44:51Z")
The code snippet you linked works for me when I include it in my `.slicerrc.py`, with volume rendering being enabled automatically when I load MRHead.
The error/warning displayed in your console may be due to something else in your `.slicerrc.py`, since `loadNodeFromFile` is not part of the code snippet you copied
---
### Author:  [@user5](https://discourse.slicer.org/u/user5)
#### Post date: [February 2, 2022, 12:24pm UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747/3 "2022-02-02T12:24:08Z")
My main error is the volume rendering cannot be enabled automatically. The warning displayed in my console is the warning of my other functions which is work normally. When I disable those functions, the automatic volume rendering still cannot work.
This is my code in `.slicerrc.py`
```auto
import SampleData
def reportProgress(msg, level=None):
# Print progress in the console
print("Loading... {0}%".format(sampleDataLogic.downloadPercent))
# Abort download if cancel is clicked in progress bar
if slicer.progressWindow.wasCanceled:
raise Exception("download aborted")
# Update progress window
slicer.progressWindow.show()
slicer.progressWindow.activateWindow()
slicer.progressWindow.setValue(int(sampleDataLogic.downloadPercent))
slicer.progressWindow.setLabelText("Downloading...")
# Process events to allow screen to refresh
slicer.app.processEvents()
try:
volumeNode = None
slicer.progressWindow = slicer.util.createProgressDialog()
sampleDataLogic = SampleData.SampleDataLogic()
sampleDataLogic.logMessage = reportProgress
loadedNodes = sampleDataLogic.downloadFromURL(
nodeNames="MRHead",
fileNames="MR-head25.nrrd",
uris="https://github.com/Slicer/SlicerTestingData/releases/download/SHA256/cc211f0dfd9a05ca3841ce1141b292898b2dd2d3f08286affadf823a7e58df93",
checksums="SHA256:cc211f0dfd9a05ca3841ce1141b292898b2dd2d3f08286affadf823a7e58df93")
volumeNode = loadedNodes[0]
finally:
slicer.progressWindow.close()
def onNodeAdded(caller, event, calldata):
node = calldata
if isinstance(node, slicer.vtkMRMLVolumeNode):
# Call showVolumeRendering using a timer instead of calling it directly
# to allow the volume loading to fully complete.
qt.QTimer.singleShot(0, lambda: showVolumeRendering(node))
def showVolumeRendering(volumeNode):
print("Show volume rendering of node " + volumeNode.GetName())
volRenLogic = slicer.modules.volumerendering.logic()
displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(volumeNode)
displayNode.SetVisibility(True)
scalarRange = volumeNode.GetImageData().GetScalarRange()
if scalarRange[1]-scalarRange[0] < 1500:
# Small dynamic range, probably MRI
displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("MR-Default"))
else:
# Larger dynamic range, probably CT
displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("CT-Chest-Contrast-Enhanced"))
slicer.mrmlScene.AddObserver(slicer.vtkMRMLScene.NodeAddedEvent, onNodeAdded)
```
This is the result now.
Is my code has anything wrong?
---
### Author:  [@ebrahim](https://discourse.slicer.org/u/ebrahim)
#### Post date: [February 2, 2022, 12:48pm UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747/4 "2022-02-02T12:48:20Z")
The decorator `@vtk.calldata_type(vtk.VTK_OBJECT)` is missing above `onNodeAdded`
---
### Author:  [@user5](https://discourse.slicer.org/u/user5)
#### Post date: [February 2, 2022, 12:58pm UTC](https://discourse.slicer.org/t/problem-in-loading-volume-rendering-automatically/21747/5 "2022-02-02T12:58:03Z")
I thought that the first line is useless 😂.
It works now. Thanks you so much.