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Realworld scale modeling questions (sorry if its wrong forum)

Hello there! Sorry if its wrong forum, but i am really tired of searching answers for like about a few months already.
I really like CG and my goal is to make CG short movie sometime in future. And, i had good start in modeling.

Well, to my questions, tbh its only one, which makes a lot of headache for me: how artists make characters at specific height? 

Its told that people use heads rule to make characters proportionally correct, and said ' average adult human is 7.5/8 heads tall ', but 7.5 character can be either 180cm tall, or 1.8m tall, depends on scale, so, heads rule is just proportion thing. 

I am really annoyed already of this stuff (even though i know that by anatomy height is changing cuz limbs get shorter/longer, calculating this in zbrush is some kind of, how i say it, 'unconfortable'.).

It's said in every tutorial that you MUST work in realworld scale, cuz vfx stuff and so on and so forth. And realworld scaling keeps things consistent, and i like working that way.

I wanted to start making characters, and then i've got confused at one thing - height. I was checking some 3d scans, and there was a 164cm tall female, she wasn't even 7 heads, more like 6.8. I am personally not intended to make exactly 155, 157 or whatever height is said, i want to make more average ones, but i want to understand how it works.
Like if i know i want my female to be 165-170cm, what should i do? Do i just need to make my character 7.5 heads and scale it to 165-170cm or what? Also i am interested in the thing: males are taller than females in average, and even if i have both male and female at 7.5 heads, their height will be different. So, if i begin to make my char entirely in zbrush, without making base at needed height in maya first, how then i make it at that height after? Like do i just really scale it uniformly and that's it? meaning i just can make one figure at 7.5 heads, first will be male at 180cm, then i make female out of it and scale it down to 170cm? I am so much bothered cuz, i.e, i model my props at its real world dimensions, and if i make character in wrong scale, they won't fit in hands. 

Soo, in short, how people handle character's height in production? Thanks to anyone in advance.

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  • Alex_J
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    Alex_J grand marshal polycounter
    You are confusing some terminology I think.

    7 heads is usually talking about proportions. Proportions are used to make sure your human looks like a human and not a chimpanzee or an alien. For instance, if a persons head is a certain size, then their hips must be a certain size, otherwise they will look bizarre, right?

    There is no magic formula for proportions, just guidelines. A big part of learning anatomy is learning how to identify when proportions are no longer within the realm of believability.

    Scale is talking about what units of measurement you have set in your modeling/rendering software. For instance, if you have your 3d package set to meters as the default unit and export your human that way, then you may face problems with your subsurface scattering shader in your render package because it is working by the centimeter.

    You will have problems working on a team if you export your human model at 6 meters tall instead of 6 feet tall, because the vehicle modeler exported the vehicle in feet. Now your models don't match and somebody has to go through and rescale things.

    It's easy solution though. Just have a reference model - almost all 3d apps come with a standard sized human. And if you mess up and export something at wrong scale, no big deal to fix that and export again. Most of the programs now have most of that automated so you rarely have problems with it.


  • Revizion
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    Alex_J said:
    You are confusing some terminology I think.

    7 heads is usually talking about proportions. Proportions are used to make sure your human looks like a human and not a chimpanzee or an alien. For instance, if a persons head is a certain size, then their hips must be a certain size, otherwise they will look bizarre, right?

    There is no magic formula for proportions, just guidelines. A big part of learning anatomy is learning how to identify when proportions are no longer within the realm of believability.

    Scale is talking about what units of measurement you have set in your modeling/rendering software. For instance, if you have your 3d package set to meters as the default unit and export your human that way, then you may face problems with your subsurface scattering shader in your render package because it is working by the centimeter.

    You will have problems working on a team if you export your human model at 6 meters tall instead of 6 feet tall, because the vehicle modeler exported the vehicle in feet. Now your models don't match and somebody has to go through and rescale things.

    It's easy solution though. Just have a reference model - almost all 3d apps come with a standard sized human. And if you mess up and export something at wrong scale, no big deal to fix that and export again. Most of the programs now have most of that automated so you rarely have problems with it.


    So, you mean i just sculpt my character at 7 / 7.5 or whatever heads proportions, and then scale it to a number of centimeters  i need? 
    I can, actually use those 3d scans, as they're more accurate, it won't be problem ofc, the thing i just wanted to know what's is the correct workflow. Just imagine boss comes and says, we need that male to be at 185 cm, and this female 163cm tall. So, in this case i just sculpt proportionally and then just scale the whole thing to either 185 or 163cm in my target software? 
  • Alex_J
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    Alex_J grand marshal polycounter
    Yes.  Proportions and scale are two independent things.


  • birb
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    birb interpolator
    Be careful, dimensions, scale, and measurement units aren't the same thing. As far as I know most 3D packages make a distinction between these three properties.

    Dimensions are the real size of the object in the 3D space. Example, an:
    2__ x 2__ x 2__ cube.

    The unit of measurement is the in what unit this cube is:
    2m x 2m x 2m



    The scale is how big, in relation to the original dimension, the cube is. It's a type of transform applied on top of the original dimensions.
    A cube scaled by 3 in all axis measures 6m x 6m x 6m.



    The original dimensions aren't lost when scaling something, you can revert to them by using a scale of 1.

    This can result in some oddities as shaders not working properly when you have a scaled up/down object or dimensions mismatch when importing or exporting objects to a different software without setting the correct measurement unit or converting between them.
  • Revizion
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    Yeah, i understand that thing, and how shaders work. I just need to know if its ok to scale uniformly after sculpt is done to a certain amount of centimeters (and apply transforms so scale in 3d world will be 1.0, but at same time it will have dimensions of what i need). Because human height in reality change non-uniformly, limbs get longer, body too, so people become taller and slender like, or shorter, meaning i.e. head will be the same size. If i take two exactly the same humans 7.5 heads, and make one shorter by scaling down, hands, feets and head(everything basically) will be smaller, which is not correct. Correct way will be making legs, arms and body shorter, which will make shorter human, but at same time, it won't be 7.5 heads, it will be smaller than that. I tried to google things related to that, but only found 8 heads rule, which is only proportions. Like for real, google found nothing except 'humans are 7/7.5/8 heads tall in average' and those heads can be at any scale, meaning i can have a statue of 3 meters and real human 1.7m with exactly same proportions. So that's why i decided to create a thread here and ask how artists handle that.
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