Hello
This plugin is a tool that allows you to place one or more objects on the floor.
The use is very simple:
Select the tool, then click on each object you want to put on the floor.
You can specify the level (and Unit) at which you want to place the object
Parametric, Polygonal, Null object, Nurbs, Generator, MoTexte, Cloner, Spline objects can be moved
If this tool is useful for you, or if you find a bug 
Let me know.
For Cinema4D R13, R14, R15, R16, R17, R18, R19, R20:
OnFloor
Hi all
This is my first plugin;)
It is an import of wavefront file, replacing the one integrated in C4D, which has some problems with the materials.
Tell me what you think 
Wavefront Import
@C4DS
Although a solution has not been given (as I wish to do), explanations have been provided. I have therefore considered it resolved.
For IRL reasons, I could not do so. I will be able to get back to it, and if I find THE solution, I will post it
Thank you Sebastian
And thanks to those who helped me on this forum, and who allowed me to finalize this plugin
I would probably have a lot more questions, because I started a plugin for the creation of a road network (a little like House Builder)