To any buff/moodlet is associated a moodaxis. There are 6 axis:
None / Angry / Fulfilled / Happy / Stressed / Uncomfortable

The mood of sims is calculated adding up the effect value of the buffs/moodlets they
got (I guess there are other factors too), so, generally speaking, negative values are
bad and positive values are good. But if we take in consideration these axis, then an
angry sim is a sim with one or more moodlets with a negative value on the angry axis
and if a moodlet has a positive value on the "Uncomfortable" axis it means the sims
feel more comfortable. Worst explanation ever but I'm tired and not in a good mood.

I did a little mod that iterates on every moodlet that a sim has and calculates the total
for every axis to get a better overview of his mood, like a very raw emotions' system.

I show the info with a modal dialog, but this solution is not very handy in my opinion.
Is there any chance to mod the game interface to change the tooltip you see when
hovering the mouse pointer on the active sim portrait? It shows the name of the sim
and I'd like, if possibile, to show also his/her emotions or the most intense emotion
that [s]he feels in that moment.

I don't want to copy TS4 and this is probably useless with this game engine but
seemed nice to me to get a better picture of what sims are feeling.

Tips on what names use for "emotions" are welcome and also about a better way
to format the presentation of the data: using bars would be nice but I don't know
if it's possibile, using colors too would be useful.

EDIT: attachment removed. Working on it.

Have you thought of using the simplest solution of displaying text: StyledNotification.Show(...) ?
You can use \n in STBL to format text so that each emotion goes into another line.

Great discovery! In Nona's old tutorial at Simlogical (sadly it has closed down), she didn't mention the use of such emotions.
Now there is a problem: is there actually gameplay significance when it comes to emotions: I think what you're saying is that with there are two contrasting ends of emotion groups (Fulfillment vs unfulfillment; happiness vs sadness). The meter goes one way or the other depending on the Sim's moodlet's axis group.

But does this affect actual behaviour?

Yeah, I could have also used a notification, I wanted to try something new and this
is just a temporary solution. As I said, I'd like to display the data with a tooltip, but
I guess that also using interactions to ask/tell a sim how he/she feels can work for
a more role-playing-ish approach.

I don't think it's a big deal, probably no one cared about it since it doesn't affect
the gameplay whatsoever. I guess it's one of those features not fully developed.
The official names of the "emotions" are those listed at the top of my post, the
others are made up by me trying to find their antonym. From what I've seen with
a quick look at the buffs' list, some axis are only used with positive values, some
only with negative ones, so probably a "calm sim" is a sim with simply "0" in the
anger moodaxis rather than a sim with a positive value in that axis. In order to
make a correct emotions' chart it takes to check exactly the min and max values
that each axis can reach (or at least check if both positive and negative values
are assigned to them) to understand when you can call a sim sad, relaxed or
whatever. The real question here is: is this worth it?

I would say that if the emotions don't have real gameplay significance...
1. Would you consider changing that? For example, skill multipliers, or increased lucky-ness for Sims with some traits, or simple value tweaks. It would be cool to develop a small emotions system. In fact I start to think this is the original design of TS4 emotions nowadays. I always have the dream of modding TS3 to possibly help it surpass TS4 lol Just my dream...

2. If you won't do so, then I see little significance. It doesn't mean something to me ATM.

I think using bars are rather cost-effective no matter you are going to implement gameplay content with corresponding emotions or not.

Hot-headed sims are more likely to do rude interactions if they are angry, plus all of their anger moodlets are 50% more effective and they get mad instead of feeling sad or uncomfortable. Grumpy sims also have a mood penality by default and feel sad instead of feeling angry or uncomfortable. This is probably why it conflicts with Hot-headed too. So yes, it has some gameplay significance

I bet it also affects the social interactions' autonomy for everyone in general.

Maybe I was too quick to say it doesn't affect gameplay, but I think in most/all cases the
game just checks if sims have a certain moodlet, it doesn't calculates the "total moodaxis"
(one could argue that it's the same thing and in a way it's true).

I haven't give up on this, I'm just waiting for some inspiration on how to use it and what
is the best way to show the informations (as a kind of cheat like it is now or as themed
interactions). I think that even if it doesn't affect gameplay, some players may like to know
more about sims's mood. The name I've used in the mod, "emotions", is misleading though.

I like the idea of being able to ask about another sim's feelings through a social interaction
But being able to see the emotions like a regular cheat is more practical though. I also have an idea about the mod's name...how about "SimEmpathy"?

Apologies, didn't see your reply until now.

You were right, Blackcatluna, moodaxes are actually used, to some extent, by the engine
and have a meaning/impact in the gameplay: I can confirm that the HotHeaded trait, like
you said, and also the Neurotic trait take into consideration, respectively, the Angry and
the Stressed moodaxes. Maybe there's more to it. And the name you suggested inspired
the name I'll give to this mod ^^

It's going to be medio... wait for it...

...cre!

I published a beta version HERE.

I'd like to get feedback and help on the following things:

NON TECHNICAL STUFF
- better set of animations: it's hard to test an animation with the mod itself, so I suggest to use Animation Player by cmomoney. If it works there, it will work with this mod too
- better set of thought balloons, having them all custom made will be nice
- how to format and display the MoodScanner results (I'm afraid I'll also need technical help for this)
- check the spelling and grammar of the mod's description. If there's something not clear or poorly phrased let me know. Also the messages you get from the mod in game, tell me if there's something that doesn't sound good or could be improved.

TECHNICAL STUFF (all about the social interaction)
- routing: handle sitting target and avoid "repositioning" if already at the right distance.
- better handling of the autonomy: alternative to using a global cooldown
- social interaction: make it boring if used 2 times in a row on the same target

IDEAS ON HOW TO USE MOOD-AXES

Example: a "anger module" could check if the anger moodaxis exceed a certain threshold and make available new interactions under an anger sub-pie menu. Possible interactions: vent, sims talk to a friend to try to calm down; etc etc

Example of check to put in the Test method of an hypothetical Vent interaction:

It's up to you to choose a fitting angerThreshold, if you ask me I'd say about -25
EDIT: traits could be used to modify the threshold, making Sims more or less
irascible. But keep in mind that I just throwing ideas carelessly, something like
this has to be well planned and balanced.

Example: A "sad/happy module" could make sims whistle (custom animation + custom sound) to express their happiness or cry to try to remove one of the moodlets that is making them sad.

Actually I'm not sure if it's a good idea to link to my .dll only to use a method
that is 1 line of code worthy (Get*MoodAxis), better re-write it directly maybe?