Small damages are different with energy shield and without

[SoakedCrow]

It's found that there is a strange behavior of small damages like attacks of small biters. Small damages will change by using energy shield or not. I verified following methods on ver0.13.20 and ver0.14.9. (edited)

Methods:

1. Use a mod that has following content in data.lua.

   Code: Select all

   data.raw["player"]["player"].healing_per_tick = 0;
   

2. Make a map placing a small biter not too close, not too far.
3. Start a game of the map.
4. Run the following code from console to get items.

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   /c game.player.insert({ name = "modular-armor" , count = 1 });
   /c game.player.insert({ name = "energy-shield-equipment" , count = 1 });
   /c game.player.insert({ name = "solar-panel-equipment" , count = 20 });
   

5. Equip the modular armor.
6. Put a energy shield and portable solar panels on modular armor. After charging the shield, take off all portable solar panels.
7. Approach the small biter to be attacked.
8. Count the attacks to find out breakpoint of health bar status until the player is killed.

Results:

1. By first 17 attacks, the shield is damaged and re-charged quickly by inner battery.
2. By next 143 attacks, the shield is damaged to change from 50 to 0 hp.
3. By next 471 attacks, the player is damaged to change from 100 to 0 hp.
4. By next a attack, the player is killed.

Damages from the small baiter is 0.350 per attack on shield and 0.212 per attack without shield. They should be same as bigger damages are. Is it bug?

[credomane]

That is interesting but are the defense values of the modular armor interfering? I dunno how the calculations are done/applied but this is my guess.

When the energy shield is up you are using pure energy to deflect the incoming damage.
When the energy shield is down your are taking the "leftover" damage after module armor's resistances.

My guess is the physical armor of the module armor is reducing the damage that reaches the player. The energy shield doesn't have those resistances so it eats the full power of the biter's attack.

[Ranakastrasz]

This is a mechanic change between older and newer versions.

In the current version, (To my great irritation) shields benefit from armor ratings from the modular armor it is placed in. (This does not work for vehicles, oddly enough)

It used to be, shields take 100% damage from everything, but once it breaks, armor reduction kicks in to protect your normal health.


So this is expected, and will change to your expectation as soon as you update to v14 something.


If you check the armor rating on the armor you have equipped, you will find that applying the tiny damage from the biter to it will get you the amount of damage you are observing.

[SoakedCrow]

That is interesting but are the defense values of the modular armor interfering? I dunno how the calculations are done/applied but this is my guess.

When the energy shield is up you are using pure energy to deflect the incoming damage.
When the energy shield is down your are taking the "leftover" damage after module armor's resistances.

My guess is the physical armor of the module armor is reducing the damage that reaches the player. The energy shield doesn't have those resistances so it eats the full power of the biter's attack.

I guessed too. But actually this is not right.
If the defence values are different, damages from medium biters must be different too. I verified midium biters deal same damages to the player with shield or without.

[SoakedCrow]

This is a mechanic change between older and newer versions.

In the current version, (To my great irritation) shields benefit from armor ratings from the modular armor it is placed in. (This does not work for vehicles, oddly enough)

It used to be, shields take 100% damage from everything, but once it breaks, armor reduction kicks in to protect your normal health.


So this is expected, and will change to your expectation as soon as you update to v14 something.


If you check the armor rating on the armor you have equipped, you will find that applying the tiny damage from the biter to it will get you the amount of damage you are observing.

According to change logs, the mechanism changed on ver 0.13.0.

Code: Select all

Version: 0.13.0
Date: 27. 06. 2016
(snip)
    - Armor resistances are applied before the energy shield is used.

So the mechanism is not much difference between ver 0.13.* and ver 0.14.*. I got same result on ver 0.14.9.

[Loewchen]

It would be helpful to make this investigation with .14 as this exact mechanic was changed from .13 to .14 and I highly doubt that there will be any more updates for .13 be there a bug or not.

[kovarex]

This is not a bug right?

When the biter is damaging the player, the shield is also being recharged, so part of the damage is absorbed by the shield and the other part by the player.

[Ranakastrasz]

Not a bug, just a change that is questionable.

[SoakedCrow]

I did an additional test of the following topics.

This is not a bug right?

When the biter is damaging the player, the shield is also being recharged, so part of the damage is absorbed by the shield and the other part by the player.

That means the shield can be recharged when no energy source is equiped. It's not a possibility. If it is true, there are some bugs.

I tested damage per attack in following conditions.
A. Equip a modular armor without shield.
B. Equip a modular armor with a shield that is no charged.

Result:
A 0.212 per attack
B 0.212 per attack

The result means the shield can't be recharged. So kovarex's answer is not right.

By the damage formula of wiki, 0.35 is calculated for the player equiped modular armor. But that is 0.212 in game.
https://wiki.factorio.com/index.php?title=Damage

Using the following command I tested many entities.

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/c game.player.print(game.player.selected.damage(x, "enemy", "physical"))
or
/c game.player.print(game.player.character.damage(x, "enemy", "physical"))

Almost all of them is following the damage formula of wiki. But only the player is not following it. Why does only the player have an other formula?

[kovarex]

You are right, that the formulas for when the damage is low were wrong.

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  float finalDamage = damage.amount;
  if (this->decrease + 1 < damage.amount)
    finalDamage -= this->decrease;
  else if (damage.amount > 1)
    finalDamage = 1.0 / (this->decrease - damage.amount + 2);
  else
    finalDamage *= 1.0 / (this->decrease - damage.amount + 2);
  finalDamage *= (1 - this->percent);
  return finalDamage;

The third case is wrong, as with 0 resistance it still decreases the damage.
This is the changed formula for 0.14.14:

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  float finalDamage = damage.amount;
  if (this->decrease + 1 < damage.amount)
    finalDamage -= this->decrease;
  else if (damage.amount > 1)
    finalDamage = 1.0 / (this->decrease - damage.amount + 2);
  else
    finalDamage *= 1.0 / (this->decrease + 1);
  finalDamage *= (1 - this->percent);
  return finalDamage;

[SoakedCrow]

On this condition, the second case is used. The third case has no relation.

When damage.amount = 6, this->decrease = 6 and this->percent = 0.3 the formulas return 0.35.
The damage of the player is 0.212 in game. There should be another formulas.

[kovarex]

On this condition, the second case is used. The third case has no relation.

When damage.amount = 6, this->decrease = 6 and this->percent = 0.3 the formulas return 0.35.
The damage of the player is 0.212 in game. There should be another formulas.

It actually is used, the result damage of the armor reduction (0.35), is then checked again against the resistances of the character itself.
The character has 0 resistances, but as there was the bug, it still decreased the 0.35 to lower value.

When I do this command while wearing the modular armor (while using the binary with the new formula):

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/c game.player.print(game.player.character.damage(6, "enemy", "physical"))

I get the result of 0.35