# The issue with white contour lines displayed on the front actor
**URL:** https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197
**Category:** Development
**Tags:** desktop, code
**Created:** [July 10, 2024, 8:42am UTC](https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197 "2024-07-10T08:42:41Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Tianming](https://discourse.vtk.org/u/Tianming)
#### Post date: [July 10, 2024, 8:42am UTC](https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197/1 "2024-07-10T08:42:42Z")
Hello everyone, I have encountered a small problem.
I created two actors, half cylinder A and vector arrow B, with half cylinder A at the back. When I set the transparency of A to be relatively small, about 0.16 (full transparency is 1), I saw white outline lines appearing on some arrows in front of B. I tried using
renderer-\>SetUseDepthPeeling(true);
renderer-\>SetMaximumNumberOfPeels(100);
renderer-\>SetOcclusionRatio(0.1);
But it doesn’t work, the white outline still appears.
I want to solve the problem with this white contour line, as it appears particularly prominent on another computer.
Thank you for any suggestions and responses.
---
### Author:  [@Tianming](https://discourse.vtk.org/u/Tianming)
#### Post date: [July 10, 2024, 9:10am UTC](https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197/2 "2024-07-10T09:10:52Z")
I have turned on anti aliasing and it looks very effective. It seems to have solved this problem.
```auto
renderer_->UseFXAAOn();
```