I’ve found this program called Cub3D, an Android port of Panda3D that they say is nearly fully functional, and that it generates a mini-apk which can then be compiled to an APK with the help of a PC. This is more or less what I was looking for but I’m going to thoroughly test it before I speak too soon.
Sounds like it has potential, at least. 
Is Cub3D still available? I am unable to find it in the Play Store.
It is taken off the playstore but an apk can be downloaded from apkpure.