[cpbell0033944]

It's simple – Fett started the ball rolling, now MG has taken it a stage futher.  As a geeky scientist (albeit a non-artistic scientist who's also a mathematical dunce) I love this thread. ::) ;D

[John]

I'm sorry I missed your posts about this, Fett.  I would have given you some credit if I had known about your posts on this subject.  I haven't been here that long, and haven't read the board very often since I joined.  BTW, Thanks for the better elliptical circumference equation.  It should help me out when I get to parts like chest where the aspect ratio is far from 1:1.

[ayanamifan]

lol Exactly the same calculations i have been using for years ^^ funny to see i am not the only one who calculates like this.

[John]

([(a² + b²)2]root) x 2 x pi x ratio = measurement in inches

You could simplify that to:
sqrt(2*(a²+b²))*pi*ratio

sqrt((a²+b²)/2)*2
=sqrt(4)
=sqrt(a²+b²)*sqrt(2)
=[color=red”>sqrt(2*(a²+b²))

[Fett]

I'm sorry I missed your posts about this, Fett.  I would have given you some credit if I had known about your posts on this subject.  I haven't been here that long, and haven't read the board very often since I joined.  BTW, Thanks for the better elliptical circumference equation.  It should help me out when I get to parts like chest where the aspect ratio is far from 1:1.

No need to apologize! I was just a bit dumbfounded, wondering if I had in fact made up a memory of posting things. 😀

[John]

So basically the formula Fett gave was the circumference of the circle

r=sqrt(1/2)*sqrt(a^2+b^2)
(circle circumference is 2*r*pi)

A way to look at this is:
1. Draw a circle
2. Draw a perfect square over that circle, with the bottom left corner at the center of the circle, the bottom right corner on the rim of the circle at 0 degrees, and the top left corner at the 90 degree rim point.
3. Draw a line from the bottom left corner of the square to the top right corner.  This line intersects with the circle rim at the 45 degree point.
4. Scale the graphic to the aspect ratio of the ellipse.

After doing that, the 0 degree line should be equal to a, and the 90 degree line equal to b.  That would make the intersection point drawn in step 3 to be of the length sqrt(1/2)*sqrt(a^2+b^2).  So now draw yet another circle over this set of graphics, with that line (from the center to the ellipse intersection point) as the radius.

You can see the similarity in circumference of both the ellipse and the last circle.

[John]

Speaking of height ratios, I sampled a group of 10 FBBs for their part length proportions.  Below is a text table of the average percentages for each part relative to the total body height.

	Average
Head2Collar	18.1%
Collar2Pevis	35.9%
Pelvis2Heel	46.0%
Pelvis2Knee	19.8%
Knee2Heel	26.2%
Head2Pelv	54.0%
Shldr2Elbow	17.5%
Elbow2Wrist	15.8%
Wrist2Ftip	9.0%

Here's the complete chart in image form:

[scat]

hi !
assuming  the ratio between a and b is often similar and in that way the round of the form is a factor of a dimension ( square : 4.a    – circle : 3.14.a ) …

… you can say for the bicep form , the round is 2.6 x a, then apply the ratio.

[Reason]

Wow, more excellent info. Thanks MuskelGrothe.

Just wondering what you mean by Head, Collar, and Pelvis. Is Head the top of the head or bottom of the head? The same applies for Pelvis and Knee. Also, is Collar the clavicle or manubrium (yes, I have a book on anatomy in front of me).

Also, I was wondering if I could trouble you for the average head size as a percentage relative to the total body height. That way I can convert your percentages to number of heads, which I find easier to work with.

Thanks again for all the work you've done on this.

[John]

Just wondering what you mean by Head, Collar, and Pelvis. Is Head the top of the head or bottom of the head? The same applies for Pelvis and Knee. Also, is Collar the clavicle or manubrium (yes, I have a book on anatomy in front of me).

I'm not very good with anatomical terms, but I'll try to explain the points I was using:
"Head" = crown (highest point standing up)
"Collar" = clavicle (collar bone), at the center groove/hole.  (Below the adam's apple)
"Pelvis" = lowest point of pelvis/crotch/butt standing up.  The bottom of the "V".
"Knee' = center of knee cap.
"Heel" = base where one would stand.
"Elbow" = middle of the elbow, at the tip of the bone
"Wrist" = anywhere along the wristline, but usually the side with the shortest distance from the elbow point on the pic.
"Ftip" = tip of middle finger (usually projected, as most poses aren't open-handed.)

[Author]

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