Export a scene from Godot into an easier to parse ascii format
Copy into your Godot project. ( keep addons/ascii_export filepath )
you should see this, with the scene you want exporting ( NOTE all child scenes are included )
THIS ISN'T A COMPLETE SOLUTION. I'm hoping it's hackable enough to get what you need quickly and modify it to fit your wants.
file contains one line per "thing"
first Resources. which are simply pathnames for 3d models
resources:<int>
filename.obj
house.gltf
.....
then
nodes:<int>
ClassName , NodeName , ParentName , Resource ID , 12 floats for a 3x4 matrix
eg.
MeshInstance3D,rock_B,rock_B2,37,1,0,0,0,1,0,0,0,1,0,0,0
NOTES:
ResourceID of -1 indicates there's no 3D model for this Node.
ALL matrices are in local space. When rendering you need to reference the parent node worldMatrix and multiply the local and parent world together.
example.c shows one quick way to load the file and render it