Review of Gyutaro’s final attack calculation

[FelpeXDopZ]

Introduction
Some time ago I made this calculation, but recently came to know it was rejected.
All the context regarding the feat can be found on the previous link.

Apparent issues
Two calc group members, Dark-Carioca and Dalesean027, commented on my calculation, here we summarize their thoughts:

Dark-Carioca:

1. The method used to calculate the solid volume is strange.
2. A city (the reference for the empty space in the Entertainment District) is way different from a town.
3. The result is too high.

Dalesean027:

1. The method used to calculate the destroyed volume is incorrect.
2. The distances are inflated because the scale used is wrong.
3. His recalculation fixes the errors of my own.

Addressing the issues

Regarding Dark-Carioca’s observations:
1 & 2: While he didn’t really reject the calculation, he was skeptical about the method used. Once I explained to him how the method works, he alluded that a city couldn’t be used as a reference for the empty space in the Entertainment District (ED) given the differences between both.
Because of this, I updated the blog to include an estimation of the ED fraction that’s used by buildings and the fraction that belongs to “empty space”. I also added an explanation on how the method for calculating the solid volume works. Both things can be found on the Solid Volume section. For reference, here is an image of how this section looked before the update (that is when Dark-Carioca commented on the blog):


3: As far as I know whether the result is too “high” or “low”, would be a matter of a CRT. So, I’m not sure this could be relevant.

About Dalesean027 observations:
1: He didn’t really elaborate on why he thinks the method used to determine the solid volume is flawed, so I can’t say much about this.

3: While he did made a recalculation on the same feat, it doesn’t really address mine at any time as far as I can tell, since it only appears to fix some issues from this other calculation where they used a different method (KE) to calculate the level of the feat, the same method which Dalesean’s applied on his own calculation.

2: The scale is most likely an actual issue on my calc, so we’ll dive a bit deeper into this on the following section.

The scale
In his calculation, Dalesean resorted to mine, where I estimated the brothels to be around 5.717 meters tall, height which doesn’t account for the roofs of these buildings. Nevertheless, Dalesean built the scale by taking the apparent size of an entire brothel (from the base to the top of the roof), when he shouldn’t have included the roof here, meaning his scale is also wrong.
To fix this problem, I've built 2 tentative scales that could be used for measuring the distances. Here they are.

First scale:


Second scale:


I would like to know what other CGMs think is the best scale so the calculation can be redone accordingly.

 

[Xaropadob3ta]

I agree with this, the method of finding the district size seems good too.
I ended up just accepting his pixel scale and ignored the fact that it didn't count the roofs.
It is a very broad analysis of the feat.
I'm not a CGM, but I would go with the second pixel scale.

 

[Kavopaco]

Agree with the second scale, it was about time this feat received a proper in depth calc.

Edit: First scale does look easier to determine the brothels different sections. Albeit both look usable, i guess a CGM can determine which to use.

 

[Epyriel]

All looks good, I’d be tempted to use the first scale just because it is easier to delineate where the exact boundaries of the roof, building, and floor are.

 

[KnyRaizn]

To me both can function.

 

[Passersby]

this looks nice

following

 

[Kavopaco]

Bump

 

[Laitnetop]

Imo Dale's rejection doesn't seem very well justified, setting aside the fact the scale he used is wrong, he didn't elaborate at all on why he believes the method used to calculate the solid volume is wrong nor suggested a way of improving it. The method seems reasonable to me and isn’t hard to understand.

There’s also this accepted calculation (which Dale himself evaluated) where they employed the exact same principle to obtain the destroyed volume. It’s literally the same idea, first they determine the space that’s being occupied by constructions and then they correct for the empty space inside said constructions. There only is one minor difference here and that is they assumed 10% of the area was being occupied by buildings, which seems like a rough guess as they didn’t really provide any sustain for that, the space used by constructions should be around 50% according to real life data.


Also, just to show how good Felpe’s method works, I’ll make a comparison between his method and this other approved calculation (also evaluated by Dale). Here the author calculated the volume of each building individually (gawd damn) and obtained this result for the total solid volume: 310,655 m³.

Now let’s use Felpe’s method.
In the calc above they measured the radius of the attack to be 140m, and the average height of the buildings is 36.54m (I calculated this myself from the data on the linked blog), so the volume of effect of the attack is π * (140m)² * 36.54m = 2,250,000m³

Assuming 50% of the AOE is being occupied by constructions, we get 1,125,000 m³

Finally, we correct for 80% hollowness inside the buildings: 225,000 m³. The actual solid volume is only 1.38 times higher than this, which means this method actually lowballed the real value.
If we use 65% of the AOE used by constructions (as Felpe calculated on his blog) we’d obtain a solid volume of: 292,500 m³ Which represents a 94.2% of the actual solid volume, that's an even better approximation, tho the real value was again underestimated.


As a side note, the second calc I linked was replaced by a more accurate one, though the reason for the replacement had nothing to do with the method employed to calculate the vaporized volume.

Anyways, hope this thread gets some attention.

 

[Vzearr]

@Dalesean027 @Dark-Carioca Do y'all wanna detail your sides here so I can evaluate this thread properly, since sides are 'important'.

 

[Dalesean027]

, the space used by constructions should be around 50% according to real life data.

This is fine with appropriate sourcing

Also, just to show how good Felpe’s method works, I’ll make a comparison between his method and this other approved calculation (also evaluated by Dale). Here the author calculated the volume of each building individually (gawd damn) and obtained this result for the total solid volume: 310,655 m³.

Just to clarify ss well this is not good to use as since then I've already rescinded my approval of this calc even if not in the blog itself, its got its own issues that I've already brought up elsewhere after reviewing it like a decently long time ago so I wouldn't really call this evidence.

Other than that I'd say the first scan is best to use here as in my blog I did provide an overlapped image that showed that building being on the same plane as that main road of the blood blades origin so I'd still say thats more accurate.

 

[Dark-Carioca]

Do y'all wanna detail your sides

Beyond what I said originally I don't know how much more in detail I can put it.

To be honest I completely forgot about this calc, though I do recall questioning the use of percentage for cities since this is a relatively small town (but the OP already brings that up). I don't find myself agreeing with the use of that percentage here.

I don't see what the issue is, exactly... Is there a problem with Dale's recalc?

 

[FelpeXDopZ]

Just to clarify ss well this is not good to use as since then I've already rescinded my approval of this calc even if not in the blog itself, its got its own issues that I've already brought up elsewhere after reviewing it like a decently long time ago so I wouldn't really call this evidence.

I believe Laitnetop noted that calculation was replaced, although the reason for that change wasn't related to the method employed to obtain destroyed volume.

Other than that I'd say the first scan is best to use here as in my blog I did provide an overlapped image that showed that building being on the same plane as that main road of the blood blades origin so I'd still say thats more accurate.

Should the calculation be fine if I use the first scale then?

 

[FelpeXDopZ]

I don't find myself agreeing with the use of that percentage here.

I’m not sure what percentage you are referring to here, could you elaborate a bit more? And also, why are you disagreeing with that specific percentage?

I don't see what the issue is, exactly... Is there a problem with Dale's recalc?

Yup, as I said in the OP, in his recalculation, Dale resorted to my calc, where I measured the brothels to be 5.717 meters tall, height which doesn’t account for the roofs of these buildings. However, the scale used by Dale takes the full apparent size of one of these buildings (from the base to the top of the roof), when the roof shouldn’t have been included, and this causes the scale to be wrong.

 

[Laitnetop]

Just to clarify ss well this is not good to use as since then I've already rescinded my approval of this calc even if not in the blog itself, its got its own issues that I've already brought up elsewhere after reviewing it like a decently long time ago so I wouldn't really call this evidence.

As I said, that calc was replaced by a different one, but this had nothing to do with how the volume of the buildings was calculated. The method is quite straightforward, the buildings are (more or less) cuboids, so Volume = width * length * height, which is exactly what was done, there simply is no flaw here. The reason the calc was later removed was because it assumed all these buildings were vaporized, which didn't happen as Malevolent Shrine had already turned all of them into dust, plus the vaporization value for concrete was wrong, plus the volume of heated air was also wrong. More details in the currently accepted calc.

 

[FelpeXDopZ]

@Dalesean027 @Dark-Carioca Do y'all wanna detail your sides here so I can evaluate this thread properly, since sides are 'important'.

Well, it seems that Dalesean and Dark-Carioca aren’t replying, but since they already have detailed their opinions, could you let me know what you think of the calculation, and which would be the best scale to use? Apparently, Dale is ok with the first scale.

 

[Dark-Carioca]

I’m not sure what percentage you are referring to here

The "90% of empty space" from your original calc, that's what I remembered disagreeing with due to the big differences between cities and towns.

 

[FelpeXDopZ]

The "90% of empty space" from your original calc, that's what I remembered disagreeing with due to the big differences between cities and towns.

Thanks for replying!
I see, that's one of the points that's addressed in this thread actually. I updated the solid volume section in order to include a more accurate method to estimate the solid volume in the Entertainment District. This new method consists of directly measuring the empty space proportion from two aerial shots of the ED.

 

[Dark-Carioca]

I updated the solid volume section in order to include a more accurate method to estimate the solid volume in the Entertainment District. This new method consists of directly measuring the empty space proportion from two aerial shots of the ED.

Hmm... Hadn't seen this until now. @Dalesean027 what do you think of this new method?

It seems sound enough to me.

 

[FelpeXDopZ]

Hmm... Hadn't seen this until now. @Dalesean027 what do you think of this new method?

It seems sound enough to me.

Thanks for checking the calc again!
On another note, which tentative scale do you think is better for the pixel scaling? (both can be found in the OP).

 

[Vzearr]

@Dalesean027

 

[Dalesean027]

New Method is fine but the only last contention that I have is that the destruction values should just be frag instead of V-frag as per what the actual destruction looks like. V-frag is for like pebble sized debris this is not at that level of destruction, just standard frag works here

 

[Dark-Carioca]

Hm, yeah that's agreeable.

 

[FelpeXDopZ]

New Method is fine but the only last contention that I have is that the destruction values should just be frag instead of V-frag as per what the actual destruction looks like. V-frag is for like pebble sized debris this is not at that level of destruction, just standard frag works here

That's a fair point I think. However, while it’s true some of the debris are almost as big as Tanjiro (or straight up larger), some other pieces are smaller than a hand or a foot. And It also seemed like the buildings close to Gyutaro were nearly pulverized.


Maybe I could do something similar to this calculation, where they did a 50-50 split for violent fragmentation and regular fragmentation. Would that work?

 

[Dalesean027]

That's a fair point I think. However, while it’s true some of the debris are almost as big as Tanjiro (or straight up larger), some other pieces are smaller than a hand or a foot. And It also seemed like the buildings close to Gyutaro were nearly pulverized.


Maybe I could do something similar to this calculation, where they did a 50-50 split for violent fragmentation and regular fragmentation. Would that work?

No that's not nearly enough to consider 50/50 at all even in regular frag theres bound to be a few pieces of smaller rubble, this overall is just regular frag

 

[FelpeXDopZ]

No that's not nearly enough to consider 50/50 at all even in regular frag theres bound to be a few pieces of smaller rubble, this overall is just regular frag

I wasn’t exactly suggesting a 50-50 split, but following the same principle as in the other calc, maybe a 30-70 split would be more accurate in this case. And it’s not like the small pieces in Mahito’s feat are much smaller than the ones seen in Gyutaro’s feat, they’re about the same as far as I can tell. There's also the fact that the buildings near Gyutaro seemed to be almost pulverized, so using just regular fragmentation doesn’t looks like the best option I guess.

 

[Dalesean027]

And it’s not like the small pieces in Mahito’s feat are much smaller than the ones seen in Gyutaro’s feat

The Mahito feat has the benefit that there isn't mucu debris visible at all, a few big chunks and some pebbled sized ones but overall you're not given the sheer amount of volume of debris after the feat like you are here.

As for the actual visuals of the feat, I'm gonna keep my current stance since the manga does not depict the destruction as pulverization or violent fragmentation

 

[FelpeXDopZ]

The Mahito feat has the benefit that there isn't mucu debris visible at all, a few big chunks and some pebbled sized ones but overall you're not given the sheer amount of volume of debris after the feat like you are here.

As for the actual visuals of the feat, I'm gonna keep my current stance since the manga does not depict the destruction as pulverization or violent fragmentation

Ok, I think that makes sense.
I’ve changed the destruction value to regular fragmentation and used the first scale from this thread. Could you check the calculation again please?

 

[Dalesean027]

Ok, I think that makes sense.
I’ve changed the destruction value to regular fragmentation and used the first scale from this thread. Could you check the calculation again please?

Maybe I misread but shouldn't
0.8 * 7.3774 + 0.2 * 2 = 6.30192 J/cc

Also what changed with the volume, it was previously 163508m^3? So some other value has been changed in the calc outside of the fix I said

 

[Epyriel]

Maybe I misread but shouldn't
0.8 * 7.3774 + 0.2 * 2 = 6.30192 J/cc

Also what changed with the volume, it was previously 163508m^3? So some other value has been changed in the calc outside of the fix I said

The upper end of concrete was used for 6J/cc (not 2) in line with cement (which did exist at the time).

0.8 * 7.3774 + 0.2 * 6 = 7.102 J/cc

 

[Dalesean027]

The upper end of concrete was used for 6J/cc (not 2) in line with cement (which did exist at the time).

0.8 * 7.3774 + 0.2 * 6 = 7.102 J/cc

Ah okay i remember the previous version used 2

 

[FelpeXDopZ]

Also what changed with the volume, it was previously 163508m^3? So some other value has been changed in the calc outside of the fix I said

The volume depends on the scale. In the old scale the building was 22 pixels high, now it’s 21 pixels, so there was a slight increase in the volume.

Ah okay i remember the previous version used 2

I used 17 J/cc for concrete fragmentation in the previous version, which is the value that corresponds to violent fragmentation.

 

[Dalesean027]

Okay should be fine now

 

[FelpeXDopZ]

Okay should be fine now

Nice, thanks a lot for your time and the evaluation!

 

[Vzearr]

Holy shit we did it, the thread got passed without me having to do any work.