The problem with angular size formulas

[Callsign_Castle]

We obviously need to strive for accuracy, but I do not know how we are realistically going to first find all of the calculations that use the wrong method, then redo and evaluate them, and finally revise all of the connected profiles.

It would turn into a massive wiki project involving as much of the staff as possible, and I would much prefer to prioritise improving the accuracy of our lower Attack Potency chart borders first.

You should ask for input from the rest of the calc group in any case.

What's wrong with the AP?

 

[Antvasima]

We have another project of trying to properly determine what our attack potency borders for tiers 9-A to 6-B or so specifically mean. Kavpeny was the one who defined them, and he isn't here anymore, and has forgotten what he based them on.

 

[Kaltias]

This feels more urgent. Making the tiers more accurate to real life is more a quality of life improvement (Still important but not as much as this), a lot of calcs using a wrong formula is a bigger issue

 

[Antvasima]

Okay. I just don't know how we are possibly going to first find and recalculate them all, and then update all of the profiles scaled from them, but we should certainly update our instruction pages to start with.

 

[Agnaa]

Perhaps this is something best done over time then? Check any angsizing calcs and if they're using the right formula, leave a comment on the blog that it's correct (to avoid doubling up on work). If it's not correct, redo the calc and change any profiles accordingly?

 

[Ugarik]

Shouldn't these two formulas mentioned in the Calculation Guide

Distance: object size*panel height/[object height*2tan(70/2)]

Size: 2tan(70/2)*distance*object height/panel height

They seem way easier than the first one + ang size calculator method.

 

[Spinosaurus75DinosaurFan]

So using these formulas we can directly get distance and size?

 

[Ugarik]

Yes, and they give you exactly the same result as the ang size calculator method.

 

[AguilaR101]

"Angle: 2*atan(tan(70/2 deg)*(object height/panel height)) "


So does this formula give you the direct result in degrees instead of radians? If one uses this there is no need to convert radians to degrees right?

 

[Antvasima]

I would appreciate if DontTalkDT could update the appropriate parts of the calculation instruction pages.

 

[Andytrenom]

"Angle: 2*atan(tan(70/2 deg)*(object height/panel height)) "


So does this formula give you the direct result in degrees instead of radians? If one uses this there is no need to convert radians to degrees right?

Yes.

 

[Antvasima]

I would appreciate if DontTalkDT could update the appropriate parts of the calculation instruction pages.

Can somebody ask him to comment here again?

 

[DontTalkDT]

I have for now simply updated the page to mention the degree thing, since that was a minor change to the page.

Kinda busy today, so I will see to integrating new formula another time.

 

[Antvasima]

Okay. Thank you for the help.

 

[Ugarik]

I guess the thread can be closed. It seems everything has been concluded

 

[Antvasima]

It is probably best to wait for DontTalkDT to perform all the necessary updates first. Or has that already been done?

 

[DemonGodMitchAubin]

So, wait, what exact formulas and exact variables should I plug into google when doing a distance calc, because I'm getting conflicting things with another person

 

[DemonGodMitchAubin]

Should I use...

This: Object Size*Panel Height/[Object Height*2tan(70/2)]

Or This: Object Size*Panel Height/[Object Height*2tan(70/2) deg]

Cause this apparently is a huge change

 

[Ugarik]

Object Size*Panel Height/[Object Height*2tan(70/2 deg)] actually

 

[DemonGodMitchAubin]

Alright, Thank You very much

 

[Ugarik]

Alright, Thank You very much

I've edited my last comment

 

[DemonGodMitchAubin]

I'll use this then: Object Size*Panel Height/[Object Height*2tan(70/2 deg)]

 

[BlackeJan]

So would this upgrade or downgrade

 

[Ugarik]

So would this upgrade or downgrade

For speed feats it can be either.

For the AP this will downgrade feats in which we calculate distance but will also upgrade those that calc size

 

[Ugarik]

It is probably best to wait for DontTalkDT to perform all the necessary updates first. Or has that already been done?

I'm going to create Calculation Guide Additions thread sometimes soon so I guess this one can be closed after I do

 

[AguilaR101]

It just came to me, since the calculation uses horizontal field of view, shouldn't the panel width be the one used in the angsizing formula instead?

ie: imagine a 1280(width)*720(height) image

The formula to detemine angle would be

2*atan(tan(70/2)*(object height/1280)) instead of 720

 

[Antvasima]

@Ugarik

Okay.

 

[SuperSaiyanKieran]

For my third calc on my speed feats for Pretty Cure Splash Star I used 2atan(tan(70/2)*(object size in pixels/screen height in pixels)). I did it in radians and then converted to degrees and got 157.12m. I then tried doing it with degrees from the beggininning and got 3.4905e+5m which I know for a fact is not the case.

I want my calc to be as good as possible, but when I try to do it this way it didn't work. Given that they were fighting above a town, my intial calc seems reasonable, but would like feedback to see what I can do to fix it, if I need to.

Edit: thank you for the help. fixed it now

 

[DemonGodMitchAubin]

It just came to me, since the calculation uses horizontal field of view, shouldn't the panel width be the one used in the angsizing formula instead?
ie: imagine a 1280(width)*720(height) image

The formula to detemine angle would be

2*atan(tan(70/2)*(object height/1280)) instead of 720

Wait, can or should you do this? because that would change my calc

 

[Antvasima]

I would appreciate if somebody could remind DontTalkDT about this thread.

 

[DontTalkDT]

If the idea behind angsizing is as explained the formulas that were suggested should be correct.

I have included them into the page now.

 

[Antvasima]

Okay. Thank you for the help.

Is there anything left to do here, or should we close this thread?

 

[Jasonsith]

Have a final check on the finishing product perhaps?

 

[Antvasima]

Can you verify the changes Ugarik?

 

[Ugarik]

The distance formula is correct

The size formula is also correct though it doesn't need parentheses in the end

 

[Antvasima]

Okay. Thank you. Should I temporarily unlock the Calculation Guide page for you, so you can make adjustments?

 

[Ugarik]

It has already been unlocked and edited somehow

 

[Antvasima]

Okay. I will lock it again then.

 

[Ugarik]

I have an idea. Maybe for panels that are stretched (like this one) it would be better to assume 180 degrees horizontal view angle.

But the problem is that the formulas above olny work if the view angle is below 180 degrees

 

[Ugarik]

Okay, I came up with the formula for 180 degrees.

Distance = 0.5*object size/object size in px*panel width

Should I explain geometric meaning of it?