# Opacity for high order function

**URL:** https://discourse.paraview.org/t/opacity-for-high-order-function/10499
**Category:** ParaView Support
**Tags:** vtk
**Created:** [October 13, 2022, 9:24am UTC](https://discourse.paraview.org/t/opacity-for-high-order-function/10499 "2022-10-13T09:24:21Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Yang](https://discourse.paraview.org/user_avatar/discourse.paraview.org/yang/32/5493_2.png) [@Yang](https://discourse.paraview.org/u/Yang)
#### Post date: [October 13, 2022, 9:24am UTC](https://discourse.paraview.org/t/opacity-for-high-order-function/10499/1 "2022-10-13T09:24:21Z")

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There are two pvd files: they all have a scalar function f(x, y, z) = x + y + z. The first store the mesh with linear elements, and the second store the mesh with second-order Lagrange elements. After setting the opacity to 0.5, the second one shows some internal faces as below. The filter `clean to grid` does not help. The data is attached.

 ![cmp-cg1-cg2](https://discourse.paraview.org/uploads/default/original/2X/0/055ff1ae12e3815fa12fab053044f8d13cc233f0.png)  
[cmp-cg1-cg2.zip](https://discourse.paraview.org/uploads/short-url/crnvWMuMgxRvCVxsyAqIuez2U3Y.zip) (21.8 KB)