# About vtkCornerAnnotation rendering slow

**URL:** <https://discourse.vtk.org/t/about-vtkcornerannotation-rendering-slow/10493>\
**Category:** Development\
**Tags:** code\
**Created:** [January 19, 2023, 1:28am UTC](https://discourse.vtk.org/t/about-vtkcornerannotation-rendering-slow/10493 "2023-01-19T01:28:06Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![marlon.ma](https://discourse.vtk.org/user_avatar/discourse.vtk.org/marlon.ma/32/6091_2.png) [@marlon.ma](https://discourse.vtk.org/u/marlon.ma)\
**Post date:** [January 19, 2023, 1:28am UTC](https://discourse.vtk.org/t/about-vtkcornerannotation-rendering-slow/10493/1 "2023-01-19T01:28:06Z")

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I finished an mpr display, but I found a problem where I used the vtkCornerAnnotation class to synchronize the window width display in each window when adjusting the window width. However, I found that the rendering speed when updating the value of vtkCornerAnnotation was slow, which caused the window to freeze, and I was pretty sure that it was due to the stuttering generated by this class, and once I blocked the code changed by vtkCornerAnnotation, the window tuning became very flowing.