# Any example or tips to render sea surface(shader+FFT)?
**URL:** https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432
**Category:** Support
**Created:** [December 19, 2021, 11:03am UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432 "2021-12-19T11:03:12Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)
#### Post date: [December 19, 2021, 11:03am UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/1 "2021-12-19T11:03:12Z")
Any example or tips to do it?
If can’t be done with VTK,any opengl integration mechanism suggestion is appreciated also.
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### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [December 20, 2021, 2:31pm UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/2 "2021-12-20T14:31:37Z")
Hi, Alex,
Can you give us a visual example of what you want to achieve? “Sea surface” can mean a lot of things in terms of computer graphics depending on your goal. For me, who makes petroleum reservoir models, the sea surface is just a flat plane painted in translucent blue. For a 3D artist making the next Pixar movie, it is a whole different game and so on.
regards,
Paulo
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### Author:  [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)
#### Post date: [December 21, 2021, 2:03pm UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/3 "2021-12-21T14:03:28Z")
Thanks,something like this,[Shader - Shadertoy BETA](https://www.shadertoy.com/view/Ms2SD1), generated by FFT
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### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [December 21, 2021, 7:02pm UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/4 "2021-12-21T19:02:32Z")
That example was made via shader. In VTK you can set shaders via one of the `vtkMapper` classes.
Please, take a look at this example: [https://gitlab.kitware.com/vtk/vtk/blob/v7.0.0.rc2/Rendering/OpenGL2/Testing/Cxx/TestUserShader2.cxx](https://gitlab.kitware.com/vtk/vtk/blob/v7.0.0.rc2/Rendering/OpenGL2/Testing/Cxx/TestUserShader2.cxx) .
I hope this helps getting you started.
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [December 27, 2021, 9:13am UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/5 "2021-12-27T09:13:17Z")
See this:
[https://discourse.paraview.org/t/visualizations-of-water/4183/18](https://discourse.paraview.org/t/visualizations-of-water/4183/18)
and this:
[https://www.kitware.com/screen-space-fluid-rendering-vtk/](https://www.kitware.com/screen-space-fluid-rendering-vtk/)
FYI @Timothee_Chabat
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### Author:  [@Timothee\_Chabat](https://discourse.vtk.org/u/Timothee_Chabat)
#### Post date: [December 27, 2021, 9:30am UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432/6 "2021-12-27T09:30:18Z")
VTK is primarily designed to render actual data (ie geometry or volumes described in a finite way) so doing sphere/ray tracing like stuff you can find on shadertoy is a bit hard. So really depends of what you want :
- If you want a scene rendered using sphere tracing for a fully procedural scene then a trick I can think of is to render a quad geometry taking the whole camera frustum and then assigning it a custom shader like @Paulo_Carvalho suggested
- If you just want to render some sea surface with actual wavelet geometry then you can create a plane geometry, subdividing it, warp it along a scalar field that you created and that is the result of your fractal noise and use the visualizations trick that @mwestphal mentioned
I don’t have any example to link but VTK is just not really designed for doing the kind of rendering you’re thinking of imo.