Why sometimes I can´t decrease activity with infiltration?

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josna238
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Why sometimes I can´t decrease activity with infiltration?

Post by josna238 »

It happened me several times in different missions (guerrillas for example).

For example I had a dark event mission with moderate and 87% I hitted on boost infiltration, the infiltration reached 152% but the activity only decreased to light-moderate when it is suposed to down to extremely-light.

Another example in a liberation guerrilla mission where I had Light activity with 115%, boosted to 200% but the activity sill stayed in Light when was soposed to down extremely light.
marceror
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by marceror »

Once enemy readiness gets to vulnerable, which is the lowest readiness, you're not going to see much more reduction, if any. Generally speaking, once the enemy is vulnerable you should launch the mission.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

This is not really how activity works.

The infiltration pct has 12 steps leading up to 100% and 3 steps after. The first 12 steps are every 8.333% and the last 3 steps are at 125/150/200. Each of these steps reduces alien presence by 1.5(+/- 0.5) aliens. For example a 0% mission will often contain 18 more aliens than a 100% mission would. These steps have nothing to do with the description that is displayed for alien activity, at least not directly.

Taking your first example a Moderate mission can be anywhere between 19-21 aliens on mission. Given you are at 87% there are 4 steps from there to 152, lowering the number of aliens by ~6 which would be 13-15, or Light. But since this number can vary somewhat, assuming you started with 21@87% you could easily have 16@152% giving you the bottom side of Light-Moderate.

In your second example you are talking about Lib 3. This mission, along with the Network Tower and HQ have a +3 Alert Modifier. This adds 4-5 more aliens. This basically guarantees the mission will have at least 12 aliens, but usually much more since you typically have more strength by then. So it is basically impossible to get to extremely light on Lib3/Tower/HQ.
josna238
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by josna238 »

Thanks a lot for answer. I thought that it worked on fixed steps, I thought that an 100% Extremely light was the same as a 124% extremely light.

So (correct me if I am wrong) a longer infiltration time can decrease alien numbers instead the description of alert was the same, for example the E-L 100% to 124% mentioned before.
Jacke
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by Jacke »

Another important effect of infiltration is the reduction of enemy vision to spot concealed troops. One of the things that makes 0-low percent infiltration missions with a timer almost impossible is that all enemy troops will spot XCOM farther away. Similarly, when infiltrating for over 100%, the drop in enemy vision can significantly help stealthing. It's also another reason to use Suppressors and carry SMGs.
dstar3k
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by dstar3k »

chrisb wrote:This is not really how activity works.

The infiltration pct has 12 steps leading up to 100% and 3 steps after. The first 12 steps are every 8.333% and the last 3 steps are at 125/150/200. Each of these steps reduces alien presence by 1.5(+/- 0.5) aliens. For example a 0% mission will often contain 18 more aliens than a 100% mission would. These steps have nothing to do with the description that is displayed for alien activity, at least not directly.

Taking your first example a Moderate mission can be anywhere between 19-21 aliens on mission. Given you are at 87% there are 4 steps from there to 152, lowering the number of aliens by ~6 which would be 13-15, or Light. But since this number can vary somewhat, assuming you started with 21@87% you could easily have 16@152% giving you the bottom side of Light-Moderate.

In your second example you are talking about Lib 3. This mission, along with the Network Tower and HQ have a +3 Alert Modifier. This adds 4-5 more aliens. This basically guarantees the mission will have at least 12 aliens, but usually much more since you typically have more strength by then. So it is basically impossible to get to extremely light on Lib3/Tower/HQ.
Are you sure of this? It directly contradicts Ufopedia; if you're right then Ufopedia needs to be updated, because there's a huge difference between -4.5 aliens and going from Light-Moderate to Extremely Light.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

josna238 wrote:Thanks a lot for answer. I thought that it worked on fixed steps, I thought that an 100% Extremely light was the same as a 124% extremely light.

So (correct me if I am wrong) a longer infiltration time can decrease alien numbers instead the description of alert was the same, for example the E-L 100% to 124% mentioned before.
My best understanding is this.

Missions start with 7 aliens. Alert level increases this value by 1.5 per alert. Missions themselves can have AlertLevelModifier added to them which increases the minimum. If a mission has +3 added to it then it will have a minimum of ~13 aliens@100%.

Under 100% infiltration will increase alert by 1 per ~8.33% up to a maximum of 12@0%. Overinfiltrating will reduce alert by 1, but only to the minimum of 1 + AlertLevelModifier.

So essentially overinfiltrating is only useful if the region has > 1 strength, or to get the alert status to Vulnerable. In higher strength regions, say a strength 6 region, going to 200% would drop it to be equivalent to a Strength 3 region.
dstar3k
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by dstar3k »

chrisb wrote:
josna238 wrote:Thanks a lot for answer. I thought that it worked on fixed steps, I thought that an 100% Extremely light was the same as a 124% extremely light.

So (correct me if I am wrong) a longer infiltration time can decrease alien numbers instead the description of alert was the same, for example the E-L 100% to 124% mentioned before.
My best understanding is this.

Missions start with 7 aliens. Alert level increases this value by 1.5 per alert. Missions themselves can have AlertLevelModifier added to them which increases the minimum. If a mission has +3 added to it then it will have a minimum of ~13 aliens@100%.

Under 100% infiltration will increase alert by 1 per ~8.33% up to a maximum of 12@0%. Overinfiltrating will reduce alert by 1, but only to the minimum of 1 + AlertLevelModifier.

So essentially overinfiltrating is only useful if the region has > 1 strength, or to get the alert status to Vulnerable. In higher strength regions, say a strength 6 region, going to 200% would drop it to be equivalent to a Strength 3 region.
This... _really_ doesn't match up to ufopedia, which quotes 'Extremely Light' at 6-9 aliens.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

dstar3k wrote:Are you sure of this? It directly contradicts Ufopedia; if you're right then Ufopedia needs to be updated, because there's a huge difference between -4.5 aliens and going from Light-Moderate to Extremely Light.
I'm 99.824% sure that infiltrating to 200% will not turn a Light-Moderate into an Extremely Light as this would require at least a drop of 7 aliens to go from 16 to 9. At best it would be the high end of Very Light or the low end of Light.

If UFOPaedia is saying that each step in infiltration changes the alien count by 3 then it is wrong as this would be 3 aliens per step, or +36 aliens at 0%, which is obviously not the case. I did a 0% supply raid in a high strength region that spawned as Extremely Heavy(30-32) and the total enemies spawned was 48, which is roughly 18 more aliens, or 1.5 per alert.

I guess there is a lot of misinformation out there on this. Basically that label that you are shown in game is giving you a range of what currently exists and has nothing whatsoever to do with the mechanics of the actual choosing of the number of aliens.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

dstar3k wrote:This... _really_ doesn't match up to ufopedia, which quotes 'Extremely Light' at 6-9 aliens.
I have never seen a mission spawn with less than 8. I run with a mod that shows the total aliens on the map. Extremely Light missions have always showed up with either 8 or 9, I don't think it can go lower than that.
Tuhalu
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by Tuhalu »

I've seen 7 aliens once or twice. It's just very uncommon.

Sounds like ufopedia is wrong. Excepting the special modifiers for certain missions, each step reduces activity by a whole category. Light > Very Light > Extremely Light for instance. A normal Light-Moderate can always be reduced to Extremely Light if you 200% it.

Sometimes you get a wierd effect where the category goes up with high infiltration. Some of those are due to force level increasing rapidly. The rest are probably due to wierd interactions with the mission modifier.

The categories only relate to how many normal enemies are in a mission. Turrets do not count and any zombies you wind up having to deal with don't count either (for obvious reasons).
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

Tuhalu wrote:Sounds like ufopedia is wrong. Excepting the special modifiers for certain missions, each step reduces activity by a whole category. Light > Very Light > Extremely Light for instance. A normal Light-Moderate can always be reduced to Extremely Light if you 200% it.
No, this is the part that is wrong. The categories have nothing to do with the mechanics. The number of aliens has to do with the alert level, the category is just a description. A Light-Moderate can be 16-18 aliens. Infiltrating to 200% reduces this by 4-5 aliens. At best you can turn a Light-Moderate with 16 aliens down to a Very Light with 10, but it may only take it from 18 to 14 making it a Light.

Code: Select all

+AlertModifierAtInfiltration=(Infiltration=0.00, Modifier=12)
+AlertModifierAtInfiltration=(Infiltration=0.09, Modifier=11)
+AlertModifierAtInfiltration=(Infiltration=0.17, Modifier=10)
+AlertModifierAtInfiltration=(Infiltration=0.25, Modifier=9)
+AlertModifierAtInfiltration=(Infiltration=0.34, Modifier=8)
+AlertModifierAtInfiltration=(Infiltration=0.42, Modifier=7)
+AlertModifierAtInfiltration=(Infiltration=0.50, Modifier=6)
+AlertModifierAtInfiltration=(Infiltration=0.59, Modifier=5)
+AlertModifierAtInfiltration=(Infiltration=0.67, Modifier=4)
+AlertModifierAtInfiltration=(Infiltration=0.75, Modifier=3)
+AlertModifierAtInfiltration=(Infiltration=0.84, Modifier=2)
+AlertModifierAtInfiltration=(Infiltration=0.92, Modifier=1)
+AlertModifierAtInfiltration=(Infiltration=1.00, Modifier=0)
+AlertModifierAtInfiltration=(Infiltration=1.25, Modifier=-1)
+AlertModifierAtInfiltration=(Infiltration=1.50, Modifier=-2)
+AlertModifierAtInfiltration=(Infiltration=2.00, Modifier=-3)
These are the breakpoints. The negative modifiers past 100% cannot bring the alert below 1 + MissionAlertModifier. The modifier can be 0, making the minimum 1 for most missions.
Jadiel
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by Jadiel »

It's worth noting that there is a random factor applied to break points, making it possible that they will occur slightly before the table above, but in general chrisb is exactly right.
Kyrsoh
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by Kyrsoh »

Chrisb is right.

My basic strategy is to make and gear a squad to deal with the baseline (100% infiltration) enemy activity. If I can overinfiltrate it, they will have an easier assignment but this is a bonus for me. I use infiltration boosts to reach at least 100% if necessary. If I can't deal with the baseline activity, or I can't reach 100% with or without the boost, I just skip the mission.

Dealing with the baseline enemy activity pods not means that I want to kill'em all, just handle the mission with good chances.

What do you think about that the word "baseline" is just one letter different from the word "vaseline". Is this a coincidence or just perfect game design? :o
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

Jadiel wrote:It's worth noting that there is a random factor applied to break points, making it possible that they will occur slightly before the table above, but in general chrisb is exactly right.
Yes, after re-reading the code it seems like there is a call to RAND based on a fractional part of the modifier step.

Code: Select all

	foreach default.AlertModifierAtInfiltration(AlertLevelModifier, idx)
	{
		if (AlertLevelModifier.Infiltration > CurrentInfiltration)
		{
			break;
		}
	}
This first part iterates the breakpoints, stopping when it reaches the first one that is beyond the squads current infiltration point.

Code: Select all

	Infiltration_Low = default.AlertModifierAtInfiltration[idx-1].Infiltration;
	Infiltration_High = default.AlertModifierAtInfiltration[idx].Infiltration;
	fAlert_Low = default.AlertModifierAtInfiltration[idx-1].Modifier;
	fAlert_High = default.AlertModifierAtInfiltration[idx].Modifier;
		
	fAlertnessModifier = fAlert_Low + (fAlert_High - fAlert_Low) * (CurrentInfiltration - Infiltration_Low ) / (Infiltration_High - nfiltration_Low);  // goes down when infiltration is high
	FractionalBit = Abs(fAlertnessModifier - fAlert_Low);
	if(`SYNC_FRAND() < FractionalBit)
	{
		ArrayIndex = idx - 1;
		iAlertnessModifier = Round(fAlert_High);
	}
	else
	{
		ArrayIndex = idx;
		iAlertnessModifier = Round(fAlert_Low);
	}
This second part grabs the values of the the one it found and the one before it.

So if you infiltrate to 175% for example, the formula for fAlertnessModifier would look like.

Code: Select all

	fAlertnessModifier = -2 + (-3 - -2) * (175 - 150) / (200 - 150) ; -2.5
	FractionalBit = Abs(-2.5 - -2) ; 0.5
LordYanaek
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by LordYanaek »

chrisb wrote: My best understanding is this.

Missions start with 7 aliens. Alert level increases this value by 1.5 per alert. Missions themselves can have AlertLevelModifier added to them which increases the minimum. If a mission has +3 added to it then it will have a minimum of ~13 aliens@100%.
Can you point me to where you found those numbers. Are they lost somewhere in the (huge) XComMissions.ini
If UFOpedia is wrong it have to be corrected but i'd like to have a look at the numbers myself before doing any edit.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

LordYanaek wrote:
chrisb wrote: My best understanding is this.

Missions start with 7 aliens. Alert level increases this value by 1.5 per alert. Missions themselves can have AlertLevelModifier added to them which increases the minimum. If a mission has +3 added to it then it will have a minimum of ~13 aliens@100%.
Can you point me to where you found those numbers. Are they lost somewhere in the (huge) XComMissions.ini
If UFOpedia is wrong it have to be corrected but i'd like to have a look at the numbers myself before doing any edit.
Not yet, I'm still looking through the code to find out exactly where the alert level gets turned into a certain number of enemies. I've found stuff on how the alert level gets determined, but not that part where the enemy count is determined. This would need to be calculated prior to the pod selection process, but I'm still stuck on where exactly that occurs.
LordYanaek
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by LordYanaek »

OK. Thanks for investigating then :)
josna238
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by josna238 »

I am still quite confused with this matter because I have situations that I can't match with the mechanics I know (from you and ufopaedia). For example this one has just happened:

Mission: Supply Raid
Region Srength: 8
Activity at 100%: Very heavy
Boosted at 114%
Activity at 200%: Heavy.

I thougth it should be down to Moderate.

Note: and if anybody is going to tell I shouldn't boost raids, please don't. I don't like to do "hyperswarming" raids to trick the game. If I can chose to fight 19 aliens or 30 I chose 19.
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

Very-Heavy is 28-30 aliens. Heavy is 25-27. So at the most extreme you have 30 -> 25. Infiltrating from 100 -> 200 removes 3 alert level from the mission. Alert level is ~1.5 aliens, so you removed 4.5 aliens.

If the number of aliens was 28 it might have dropped to around 23 which would have been Moderate-Heavy.

The mistake people are making is thinking that each 'step' affects the label (ie Moderate). It does not do this. That label is nothing more than an approximation of the actual aliens on the mission. It has nothing to do with any game mechanics at all. If any other source says differently than it is wrong.

Also, if it were true, then the mission would not have been Very-Heavy to begin with, it would have been Swarming++ since it was an 11 Alert mission.
josna238
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by josna238 »

Now I understand it totally. So we can sometimes know wich is the exact amount of aliens. In my las example was a mission that marked Very heavy (28-30) and after boosting (-3 levels mean -4.5 aliens) I had heavy (25-27), so the only way to do this works is that my "Very Heavy" meant 30 aliens and after boosting (-4.5) my "heavy" meant 25 aliens.

So I guess I have exactly 25 aliens. I haven't played mission yet I am going to do it now and will check if I am right
chrisb
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by chrisb »

Right, based on my experience, an alert level has a 50/50 chance of being 1 or 2 aliens added. This is why 0% raids typically add ~18 aliens, but could really be anywhere in the range of 12-24.

I have seen # of enemies drop by 4 after dropping alert level by 2. Recently had a Heavy troop column drop to Moderate as my infil went from 50% -> 75%. There were 21 aliens on the map when I started it, so there must have been 25@50% and each of the 2 alert levels dropped it by 2.
josna238
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Re: Why sometimes I can´t decrease activity with infiltration?

Post by josna238 »

Mission finished and had 25 aliens (plus some zombies). Seems that you found te exact mechanic. So somebody should tell the ufopaedia editor yhat their info is wrong.
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