# Why Points/Wireframe display repr. only show outside faces

**URL:** https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915
**Category:** ParaView Support
**Created:** [November 16, 2018, 7:59am UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915 "2018-11-16T07:59:12Z")
**Posts on this page:** 7
**Page:** 1

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### Author: ![banesullivan](https://discourse.paraview.org/user_avatar/discourse.paraview.org/banesullivan/32/11714_2.png) [@banesullivan](https://discourse.paraview.org/u/banesullivan)
#### Post date: [November 16, 2018, 7:59am UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/1 "2018-11-16T07:59:12Z")

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Why do the _Points_ and _Wireframe_ display representations only show external faces for `vtkImageData` and `vtkRectilinearGrid`s? When I select _Wireframe_/_Points_, I want what the **Extract Edges** filter produces. And when I select _Points_, I want to see all points in the data set. Am I missing something here?

Also, why is there no option for _Volume_ rendering for `vtkRectilinearGrid`s?

### Points/Wireframe Examples

_To reproduce, use the **Fast Uniform Grid** source_

This is what I expect when selecting the _Points_ representation. (I got this by applying an **Extract Edges** filter. This routine is a bit cumbersome and after generating that data object, I can’t use it down the pipeline).

 ![extract%20edges](https://discourse.paraview.org/uploads/default/original/1X/6fce42c8011294520ce5b5109d80ad96600b603a.png)

This is what I get when selecting the _Points_ representation for `vtkImageData` (not very useful/insightful):

 ![points](https://discourse.paraview.org/uploads/default/original/1X/cc77c07abcc95a55550f0dd4f4e39a7e0087d0cb.png)

and similarly for the _Wireframe_ representation:

 ![wireframe](https://discourse.paraview.org/uploads/default/original/1X/6877031547af7ec1839faa4f96d916aff3e388c4.png)

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [November 16, 2018, 8:06am UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/2 "2018-11-16T08:06:22Z")

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This is indeed a limitation of the implementation that actually display only the external faces.  
I’m not sure we want this to change.

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### Author: ![banesullivan](https://discourse.paraview.org/user_avatar/discourse.paraview.org/banesullivan/32/11714_2.png) [@banesullivan](https://discourse.paraview.org/u/banesullivan)
#### Post date: [January 25, 2019, 11:25pm UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/3 "2019-01-25T23:25:37Z")

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> [@mwestphal](#):
>
> I’m not sure we want this to change.

Would it be possible to work around this without applying an extract geometry filter? I’m begging to realize why this is the case but I’d love a way to quickly render all the points in a dataset without applying a filter that alters the data type.

These representation types are difficult to use with datasets that have irregular geometries: for example a dataset that has dense lateral points and sparse vertical points. Take this simple uniform grid that has different spacings along each axis:

Create a Programmable Source with ImageData output:

```python
output.SetDimensions(500, 500, 10)
output.SetSpacing(1, 1, 20)

```

The **Points** representation only shows the external points which hides much of the data in the dataset:

 ![external-points](https://discourse.paraview.org/uploads/default/original/2X/4/4f9eb2b5d1b50e92d8196798c429b7fe843aed02.png)

I would like a way to quickly display all of the points in the dataset when selecting a **Points** representation type like the image below (this was produced from the extract edges filter):

 ![all-points](https://discourse.paraview.org/uploads/default/original/2X/5/5444061f5cfd2aa745fac8a63b14f11277444478.png)

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 28, 2019, 11:19am UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/4 "2019-01-28T11:19:57Z")

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It is not possible yet, but It would be possible to add this feature in ParaView.  
You could also have this if you write your own representation plugin.

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### Author: ![cory.quammen](https://discourse.paraview.org/user_avatar/discourse.paraview.org/cory.quammen/32/11193_2.png) [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)
#### Post date: [January 28, 2019, 2:17pm UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/5 "2019-01-28T14:17:44Z")

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> [@banesullivan](#):
>
> I’m begging to realize why this is the case but I’d love a way to quickly render all the points

For very large datasets there are just too many points to render if you include all the internal ones. Sure, “too many” is somewhat arbitrary, but ParaView is designed for very large data where showing the internal points may not be desirable or even feasible.

As @mwestphal says, one can write a representation plugin that does show the internal points. As a faster alternative, you could also add a macro (using ParaView’s simple Python interface) that extracts the points/edges and sets the representation automatically. That would save some mouse clicks.

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### Author: ![wascott](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/w/8e8cbc/32.png) [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [January 28, 2019, 4:59pm UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/6 "2019-01-28T16:59:37Z")

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I totally agree with what @cory.quammen and others have said. However, I believe there is a way to get what you are looking for. Use the Point Gaussian representation. These will display your points as spheres, giving them a nicer look. You can control Point Gaussian down in the Properties tab. If this slows down your computer too much (spheres aren’t the fastest thing to draw), change to Shader Preset of Plain Circle. I would think we could add just a simple “point” Shader Preset, if there was a need.

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### Author: ![banesullivan](https://discourse.paraview.org/user_avatar/discourse.paraview.org/banesullivan/32/11714_2.png) [@banesullivan](https://discourse.paraview.org/u/banesullivan)
#### Post date: [January 28, 2019, 5:03pm UTC](https://discourse.paraview.org/t/why-points-wireframe-display-repr-only-show-outside-faces/915/7 "2019-01-28T17:03:50Z")

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Aha! Thanks, @wascott!

> [@wascott](#):
>
> I would think we could add just a simple “point” Shader Preset, if there was a need.

I would definitely like to see that!
