wp_skill makes you avoid bad weakpoint

[osuphobia]

Summary

Balance "wp_skill makes you avoid weakpoint not beneficial"

Purpose of change

e4e3e1c introduced is_good which separates good weakpoint that is beneficial for you to hit from bad wp. I think we can make use of it.

Describe the solution

When calculating probability of hitting wp, use erfc if the wp does not benefit the attacker.
Now when you are good at hitting beneficial wp, you will also be tend to avoid bad wp.

Describe alternatives you've considered

Adjust the default difficulty of wp, but that will lead to many side effects.

Testing

It compiled :)
With no skill and no wp prof, the probability of hitting the body armor is 40%.
With some wp_skill, the probability decreases, and reduces to nearly zero with max gun skills and full set of wp prof.

Additional context

I'm working on combining critical hit and weakpoint for ranged attack, and decide to cherry-pick this feature out first.

[Maleclypse]

Can you share the math so with like no proficiency no gun skill =base chance to hit bad weakpoint? Half proficiency and 5 guns what percentage of base weakpoint chance. Same for max and max.

[osuphobia]

Can you share the math so with like no proficiency no gun skill =base chance to hit bad weakpoint? Half proficiency and 5 guns what percentage of base weakpoint chance. Same for max and max.

Yah, still take cop z as an example:

	FALSE	TRUE
prof_gross_anatomy	0	0
prof_intro_biology	0	0
prof_physiology	0	2
prof_wp_zombie	0	2
prof_wp_syn_armored	-4	4

	wp_skill	wp_skill - difficulty	difficulty_mult	raw_chance	hit_chance
no skill no prof	-4	-14	1	40	40
3 skill no prof	-1	-11	0.999999981	39.99999924	40
3 skill wp_z	1	-9	0.999996602	39.99986409	49
3 skill wp_z wp_phy	3	-7	0.999767371	39.99069484	59
6 skill wp_z	4	-6	0.998650102	39.94600408	57
6 skill wp_z wp_phy	6	-4	0.977249868	39.08999472	47
8 skill wp_z wp_phy	8	-2	0.841344746	33.65378984	36
10 skill wp_z wp_phy	10	0	0.5	20	25
3 skill all_wp	11	1	0.308537539	12.34150155	18
5 skill all_wp	13	3	0.066807201	2.672288051	5
6 skill all_wp	14	4	0.022750132	0.910005278	1.8
8 skill all wp	16	6	0.001349898	0.053995921	0.1
10 skill all wp	18	8	3.16712E-05	0.00126685	0.003

The reweighed hit_chance is directly tested in game.

skill means you got such level of both base gun skill and certain type of gun skill.

[Maleclypse]

I’m concerned with where it ends up at the all tens but I’m also not sure that’s a realistic concern in game balance.

[osuphobia]

Then maybe floor difficulty_mult at 10% or something for bad wp?

[Maleclypse]

Thank you for doing this!