# Why does the interface refresh lag when I set opacity for the display node

**URL:** https://discourse.slicer.org/t/why-does-the-interface-refresh-lag-when-i-set-opacity-for-the-display-node/37876
**Category:** Development
**Created:** [August 14, 2024, 7:53am UTC](https://discourse.slicer.org/t/why-does-the-interface-refresh-lag-when-i-set-opacity-for-the-display-node/37876 "2024-08-14T07:53:31Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![fl\_wang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/fl_wang/32/77612_2.png) [@fl\_wang](https://discourse.slicer.org/u/fl_wang)
#### Post date: [August 14, 2024, 7:53am UTC](https://discourse.slicer.org/t/why-does-the-interface-refresh-lag-when-i-set-opacity-for-the-display-node/37876/1 "2024-08-14T07:53:31Z")

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femurClipedDisplayNode-\>SetOpacity(0.6);  
tibiaClipedDisplayNode-\>SetOpacity(0.6);

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<div class="post-metadata">

### Author: ![rfenioux](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rfenioux/32/70007_2.png) [@rfenioux](https://discourse.slicer.org/u/rfenioux)
#### Post date: [August 19, 2024, 9:17am UTC](https://discourse.slicer.org/t/why-does-the-interface-refresh-lag-when-i-set-opacity-for-the-display-node/37876/2 "2024-08-19T09:17:30Z")

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you can try `slicer.app.processEvents()` to process pending GUI events