There is an updated pull request by kawaiiamber against master on the void-packages repository

https://github.com/kawaiiamber/void-packages Field3D
https://github.com/void-linux/void-packages/pull/35042

Field3D: fix license
From the [homepage](https://github.com/imageworks/Field3D/wiki/Field3D-Home):
> # License
>  Field3D is distributed under the New BSD License.

Looking at the COPYING file, it's clauses (distribute notice in source, in binary, and don't use their name to promote stuff) make it a BSD-3-Clause license.

A patch file from https://github.com/void-linux/void-packages/pull/35042.patch is attached