# Stream trace on a shell?

**URL:** https://discourse.vtk.org/t/stream-trace-on-a-shell/10587
**Category:** Support
**Created:** [February 1, 2023, 8:33pm UTC](https://discourse.vtk.org/t/stream-trace-on-a-shell/10587 "2023-02-01T20:33:27Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![rexthor](https://discourse.vtk.org/user_avatar/discourse.vtk.org/rexthor/32/6481_2.png) [@rexthor](https://discourse.vtk.org/u/rexthor)
#### Post date: [February 1, 2023, 8:33pm UTC](https://discourse.vtk.org/t/stream-trace-on-a-shell/10587/1 "2023-02-01T20:33:27Z")

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Hi - I have a surface defined as an unstructured grid composed of vtkTriangles. It is roughly a dish shape, and has a vector array (flow velocity) at each cell center. Is there a way to trace a streamline on this surface?