Is it possible to max out two or all three Affinities?

[KrikkitTwo]

Affinity cost is determined in CivBEAffinities.xml.

To achieve 18/18/18, one may need to
Get Adaptive Science ASAP
Set a dominant affinity, and choose other choice in quests.
Level up affinities somewhat evenly(this is to maximize quest reward xp), but do not switch dominant affinity.
And reserve some progenitor ruins for final levels of non-dominant affinity.

What is the formula?

 

[ggmoyang]

Why not switch dominant? If you don't, you will end up going over on the dominant and waste points.

I didn't thought that way. You're right.

What is the formula?

I think there is no formula, there is just number set for each level.

 

[KrikkitTwo]

I didn't thought that way. You're right.

I think there is no formula, there is just number set for each level.

So it doesn't depend on the other affinity levels?

 

[ggmoyang]

So it doesn't depend on the other affinity levels?

Yes. For example:

<Row>
<AffinityValueNeededAsDominant>24</AffinityValueNeededAsDominant>
<AffinityValueNeededAsNonDominant>44</AffinityValueNeededAsNonDominant>
<NonDominantAffinityTechCostMod>4</NonDominantAffinityTechCostMod>
<HarmonyFlavorText>TXT_KEY_AFFINITY_LEVEL_UP_FLAVOR_HARMONY_13</HarmonyFlavorText>
<HarmonyFlavorAudio>AS2D_NARRATOR_SPEECH_AFFINITY_HARMONY_13</HarmonyFlavorAudio>
<PurityFlavorText>TXT_KEY_AFFINITY_LEVEL_UP_FLAVOR_PURITY_13</PurityFlavorText>
<PurityFlavorAudio>AS2D_NARRATOR_SPEECH_AFFINITY_PURITY_13</PurityFlavorAudio>
<SupremacyFlavorText>TXT_KEY_AFFINITY_LEVEL_UP_FLAVOR_SUPREMACY_13</SupremacyFlavorText>
<SupremacyFlavorAudio>AS2D_NARRATOR_SPEECH_AFFINITY_SUPREMACY_13</SupremacyFlavorAudio>
</Row>

 

[Elfdemon]

It's very hard. Currently I have a game with 8, 9 , 14, and after doing some calculations based on the XML, it seems too hard and probably impossible, even with the 3 free affinity levels in virtues still unlocked.

I don't think alternating dominant virtues work. By making one affinity non-dominant it makes it more expensive to level up so the end result is the same.