Math models like that are very tricky to model without function input, obviously.  Suffice to say, that's why it's done most often with direct mathematical equations.  I guess for that first one, HMorton, you could try subdividing a plane, with the outer edges hardened, then apply a bend modifier, or cast modifier, to bend it?  Just guessing here, but I'm thinking that would be the only way to come close.  I'm sure Lux will have the true answer if he sees this, but just remember there's a reason they invented the addon.

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Tools :  3dsmax 2015, Daz Studio 4.6, PoserPro 2012, Blender v2.74

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