@eirikr1848
Hi, I think the way to do such thing is to gather everything required on your computer, build and compile it for your device target.
Then you can install the built libraries on your device (it might fit)
Or you can package it in a click for a dedicated app to use.
Note every Ubuntu Touch devices are "stuck" in 16.04 until 20.04 is available for our OS.
Explanation:
The rootfs is locked in RO because the partition size vary and is relatively small for the system image.
You can access the userdata partition to install rather large click files, but you need to build and package an app prior to use it on the phone.
You can also use Libertine container to install/use so-called legacy apps (command line software essentially)
So to tinker with 3D you might want to build your dependencies on your desktop computer and create a native app that can use thoses libs.