tool for calculating the bodyweight of a character
Drogo Nazhur
Posts: 1,112
There is a tool called "Measure Metrics for DAZ Studio" [ https://www.daz3d.com/measure-metrics-for-daz-studio ] which provides accurate measurements of not only height / length but even circumference -- which I find especially amazing. I use this tool all of the time to help 'ground' my charcters into the real world.
The NEXT step would be to have a tool that would estimate a character's body weight based on their size. I realize that this would be a major under taking and I'm not sure how it would be done but if the circumference can be calculated, then the bodyweight can not be far behind in complexity.
Post edited by Drogo Nazhur on
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I'd say this isn't remotely possible. Even with the circumfrance measurements paired with height ones, two individuals with the same linear dimensions could vary drastically in weight due to differing tissue composition. At best, maybe a realistic weight range could be provided with dimensions, but I'd consider even that to be dubious in both liklihood of creation and probable accuracy.
Do something like this:
Once you establish the height & other measurements in Measure Metrics/Figure Metrics you can create a rough estimate by estimation using BMI charts & then Dexascan type measurements to refine your guestimate:
example:
6'0" & other measurements are known. Now you need just the weight.
Then take as an example, your average very active taller than average teenage male that is very active but not especially muscular..
Now look at a BMI chart for men & woman (bing or google search has plenty of BMI charts as images & PDFs to download) and choose various BMI on the chart & the ideal weight for your character height & age: (older usually equates with higher body fat)
For 6' from will be from about 137 lbs and a BMI of about 18 to about 184 lbs and a BMI of about 25
So if you choose an middle weight of the 137 - 184 scale for a 6' male of 165lbs you should choose an average fat mass percentage too of 15%.
a) 15% body fat of 165% = 24.75 lbs fat
b) 7 lbs as a higher bone mineral content for that size (high bone density) (you can look up average values for people via google BMC - bone mineral content / Dexascan)
c) 165 lbs - 24.75 lbs - 7 lbs = 133.25 lbs lean body mass (includes everything but bones & fat - brain is modified fat but I don't think it is counted as fat in the Dexascan)
Fat is less dense than muscle so fatter bodies will weigh less than thinner bodies per for a given same volume. The DAZ Original Morph packs - Body Morphs have Thin, Lithe, Fat, Muscular, and similar varients.
My problem with Measure Metrics / Figure Metrics is that it, or probably the DAZ G8M/G8F models because of limits that are too strick, would not allow me to actually change the measurements on a DAZ model to match the real life measurements of a real person. When a measurement in a certain part of the body got to skinny it would adjust the height down, change the head circumference, and similar behavior. The two measurements on the DAZ models that caused the most trouble (ie would change the models other measurements to be changed even if they shouldn't be) are the waist & the bicep.
For fat people or muscular people that exceed the BMI charts go to Bodybuilding.com and other such sites where people commonly post their measurements, weight, fat mass, lean mass, and sometimes rarely bone mineral content.
Of course it's not going to be exact but it can be close. I guess since you know the character's measurements you could write a goofy DAZ Studio script to simulate water displacement method of estimating body fat mass / lean mass and avoid looking all that up on BodyBuilder.com and work backwards to a 'believable weight' for that sort of body volume that would have a believable fat mass for that amount of water displacement. Write the script to take multiple slices of the body volume and sum them up from head to toe to get the total body volume. I think DAZ Studio needs more physics added to it before you can do that but I'm not sure.
I have never understood the need for Measure Metrics much less a tool for actual body weight. Seems completely pointless to me when I am creating a character with all the various sliders, but as long as some seem to have a use for it, then I hope one shows up.
Measure Metrics is cool, but what would be a big improvement is, if you could enter more than just 4 measurements to have the character calculated. So for a Genesis 9, it would be cool if you could buid characters not only with sliders but also with real measurements like arm length, leg length and so on. Especially if you like to create clothing it would be huge boos, if you could create avatars with "real" sizes.
You need to tell Figure Metrics (which is what you ar talking about - the script and utility wearables that come with and use Measure Metrics) which property to use for a aprticular measurement before you can ask Figure Metrics to attain a target value - be careful not to use two properties for different measures that might affect the same area, potentially genrating conflicts as the process runs.
Matching the dimensions of real people or commissioned characters is one reason.
By reducing bodyparts to cylinders it is possible to create a credible estimate based on average body composition.
Assuming all characters have equal bodyfat, waterretention and bone structure/density.
I don't do scripting for DAZ but if the person who coded measure metrics contacts me, I'll share my anthropometrics formulas with him.
It would be very difficult I would imagine. I wrestled Heavyweight in High School and immediately after graduation got a summer job working as a lifeguard at a municipal pool. I was 5'11" and 240 lbs. I almost was not hired because my BMI was 33.5 (obese). I had 8 percent bodyfat (while wrestling our weight was checked daily and our bodyfat weekly). The doctor was shocked when he weighed me and told me he assumed I was around 200 or 210 pounds.
My point is bone and muscle density/composition can vary greatly and will radically effect the weight between two, seemingly, similar individuals. The BMI is only an approximation and is not optimal for calculating Mesomorphs or Endo-Mesomorphs or really anyone with dense musculature (i.e. powerlifters).