# Smooth interpolation for PBR mesh environment reflections?

**URL:** https://discourse.vtk.org/t/smooth-interpolation-for-pbr-mesh-environment-reflections/14514
**Category:** Support
**Created:** [September 1, 2024, 12:25pm UTC](https://discourse.vtk.org/t/smooth-interpolation-for-pbr-mesh-environment-reflections/14514 "2024-09-01T12:25:36Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![rdbrn](https://discourse.vtk.org/user_avatar/discourse.vtk.org/rdbrn/32/5627_2.png) [@rdbrn](https://discourse.vtk.org/u/rdbrn)
#### Post date: [September 1, 2024, 12:25pm UTC](https://discourse.vtk.org/t/smooth-interpolation-for-pbr-mesh-environment-reflections/14514/1 "2024-09-01T12:25:36Z")

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I’m trying to visualize ocean waves.

I do this by defining vertical displacement for points on a grid. With PBR and texture applied this looks like:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/9/9d2d7483db8a0dbc24426a5943b818c6f816fab1.jpeg)

The mesh is clearly visible. Is it possible to make the surface look smoother? Judging from the examples I would think so but can’t get it so work.

My pipeline look as follows:

- Read grid from .stl file.  
`grid = reader.GetOutput)`

- Displace the points vertically depending on their location  
`grid.GetPoints.SetPoint(...)`

- Add texture coordinates  
`grid.GetPointData().SetTCoords(TextureCooridinates)`

- Calculate tangents  
`vtkPolyDataTangents`

polydatamapper-\>actor-\>etc.

What am I missing?

.

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<div class="post-metadata">

### Author: ![rdbrn](https://discourse.vtk.org/user_avatar/discourse.vtk.org/rdbrn/32/5627_2.png) [@rdbrn](https://discourse.vtk.org/u/rdbrn)
#### Post date: [September 1, 2024, 12:29pm UTC](https://discourse.vtk.org/t/smooth-interpolation-for-pbr-mesh-environment-reflections/14514/2 "2024-09-01T12:29:45Z")

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Found it, have to use Normals, not Tangents 🙈

 ![image](https://discourse.vtk.org/uploads/default/original/2X/8/89327cfb166d01b125168c90b72d72686e29b240.jpeg)