# Bug in documentation figure on wedge node ordering

**URL:** https://discourse.vtk.org/t/bug-in-documentation-figure-on-wedge-node-ordering/9946
**Category:** Development
**Created:** [November 24, 2022, 8:41am UTC](https://discourse.vtk.org/t/bug-in-documentation-figure-on-wedge-node-ordering/9946 "2022-11-24T08:41:04Z")
**Posts on this page:** 1
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### Author: ![philippeVerney](https://discourse.vtk.org/user_avatar/discourse.vtk.org/philippeverney/32/2484_2.png) [@philippeVerney](https://discourse.vtk.org/u/philippeVerney)
#### Post date: [November 24, 2022, 8:41am UTC](https://discourse.vtk.org/t/bug-in-documentation-figure-on-wedge-node-ordering/9946/1 "2022-11-24T08:41:04Z")

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Hi all,

Following [this Paraview question](https://discourse.paraview.org/t/node-ordering-and-volume-computation/10826/1), I think there is a bug on the wedge node ordering on [this figure in the VTK documentation](https://kitware.github.io/vtk-examples/site/VTKBook/05Chapter5/#Figure%205-2).

Indeed, on this figure, the first face 012 points inwards using right hand rule.  
However, we can read the opposite in the [VTK doxygen generated documentation](https://vtk.org/doc/nightly/html/classvtkWedge.html#details) :

> The wedge is defined by the six points (0-5) where (0,1,2) is the base of the wedge which, using the right hand rule, forms a triangle whose normal points outward (away from the triangular face (3,4,5))

Last point, [this figure in the VTK documentation](https://kitware.github.io/vtk-examples/site/Cxx/GeometricObjects/LinearCellDemo/) shows the opposite as well (same as VTK doxygen generated documentation).

I am pretty sure it is a figure error in the VTK documentation but as the VTK readme “Reporting Bugs” paragraph states, one must first “join the [VTK Discourse](https://discourse.vtk.org/) forum and ask about the expected and observed behaviors to determine if it is really a bug” before to “open an entry in the [VTK Issue Tracker](https://gitlab.kitware.com/vtk/vtk/-/issues)”.

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