# Pyramid elements C3D5 & C3D13

**URL:** <https://calculix.discourse.group/t/pyramid-elements-c3d5-c3d13/1881>\
**Category:** Code development\
**Created:** [October 20, 2023, 9:19am UTC](https://calculix.discourse.group/t/pyramid-elements-c3d5-c3d13/1881 "2023-10-20T09:19:56Z")\
**Posts on this page:** 1\
**Showing post:** 27

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**Author:** ![rafal.brzegowy](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@rafal.brzegowy](https://calculix.discourse.group/u/rafal.brzegowy)\
**Post date:** [August 18, 2026, 8:00am UTC](https://calculix.discourse.group/t/pyramid-elements-c3d5-c3d13/1881/27 "2026-08-18T08:00:14Z")

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I think that since pyvista supports the .frd format, it is worth adding support for these unofficial element types (C3D5 and C3D13 pyramids) to pyvista:

> [@CalculiX (.frd) and pyvista](https://calculix.discourse.group/t/calculix-frd-and-pyvista/3816):
>
> I am pleased to inform you that I have successfully added native support for reading .frd files directly into PyVista. This feature is currently slated for release with version 0.48, which is expected to be available around April. This implementation will allow users to load .frd file seamlessly without requiring external conversion scripts or intermediate steps.

feature-request pyvista:

> <https://github.com/pyvista/pyvista/issues/8923>
>
> \### Describe the feature you would like to be added.
> 
> Could you please add to th…e .frd reader the ability to read the not yet officially introduced pyramid-type elements: C3D5 and C3D13? 
> 
> There is a patch file available on the CalculiX forum thanks to which the solver supports these elements, but the official post processor (cgx) does not support them:
> 
> https://calculix.discourse.group/t/pyramid-elements-c3d5-c3d13/1881/19
> 
> 
> 
> 
> \### Links to VTK Documentation, Examples, or Class Definitions.
> 
> https://github.com/Dhondtguido/CalculiX/pull/130
> 
> C3D5 -\> VTK\_PYRAMID
> \<img width="138" height="151" alt="Image" src="https://github.com/user-attachments/assets/5de22e71-eb61-4eb9-acaf-5c1948e55ba0" /\>
> 
> C3D13 -\> VTK\_QUADRATIC\_PYRAMID
> \<img width="165" height="154" alt="Image" src="https://github.com/user-attachments/assets/bf58dea2-8397-43a6-a3e5-d8e35c73da9c" /\>
> 
> \### Pseudocode or Screenshots
> 
> \<img width="554" height="379" alt="Image" src="https://github.com/user-attachments/assets/5e6c96ee-4dbf-4a6d-a31c-f5cb3c6495da" /\>

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