This tutorial http://sims4studio.com/thread/3517/...-emit-emotional explains that a value of "375" gives you +2 moodlet and I want to know what value I have to use to get +10.
Also, there's a very interesting picture but I don't understand it.

Hi MerSummoner,

If I understand well, this is not a tutorial to change environment score but emotional score (like flirty).

If you want to change environment score you have to modify two things :
1- In S4S, Warehouse Tab, click on Object Catalog, scroll down and find the "ObjectTooltipTags" line and click on "Edit elements" (or something like that). Then modify the "AmbienceHappy" value (1 is 1, 2 is 2, etc.). If there is nothing in this section you have to click on "Add" and select "AmbienceHappy".
2- This is not over, you just changed the environment score in the catalog description. Now you have to edit the Object Definition. Click on it and find the "PositiveEnvironmentScore" line. Then change the value :

1->1
2->4
3->16
4->25
5->73
6->100
7->155
8->270
9->341
10->640

I found these values in TS4 objects. Note that you have to edit each ObjectCatalog and ObjectDefinition. Tell me if it helps you.

Jim

Thank you! 640 is the number I was searching.