What would be the best way to model this?

hello all,

i’m wondering what would be the best/ideal way to model this domed surface … the best way to get the kind of shape i like is to use a patch surface but that isn’t very precise and not ideal for further transformations i want to use this shape for. So i’m wondering what the ‘proper’ way to create this surface would be.

Here are some of the isocurves that would define this shape.

and here is the file with these curves:

surfacetopoogy.3dm (159.8 KB)

Hi Chris - with this input, I do not see how you can easily get away with something other than a trimmed surface like a Patch. You can use History with Patch, which may help.

You could work on getting the curves to intersect - if they can stay nice and clean and actually intersect, there’s a better chance of the final surface hitting them all.

Also, I would avoid fiddling the ends of the curves like this:

that reversal there is going to mess with how the patch finds the edges cleanly - if there is a transition like this around the edges, I’d add this as a separate surface - like a blend or fillet - after.

-Pascal

hi Pascal, thx for your advice … the curves in this file really are just an example, don’t pay to much attention to the details … i’ve done this properly with curves intersecting properly and a smooth domed profile but i’m stuck as to which technique to use to turn these curves into a surface … i’m more looking for general advice on how to approach surfaces like that.

here is one other technique i’ve been using: revolving a curve to create an egg like shape and then splitting of a section with a plane:

eggslice.3dm (212.2 KB)

the reason i’m asking is that i’ve never learned or studied 3D modelling properly, i’ve done it for years and usually i get close to what i want but i thought i’d ask the professionals on how to do it the right way :blush:

That’s fine, but all I have is the curves you send - if you complain that Patch is not precise, I have to look for why that might be and try to point out what I find, not making any assumptions. At any rate, in my opinion, Patch is the way to surface the curves you sent, if the curves are clean.

-Pascal

sorry pascal, what i meant with ‘patch is not precise’ is that as far as i’ve experienced the patch surface will always be an approximation, depending on the number of spans and stiffness settings, i can work with both the patching method and the ‘egg-slice’ method but i was wondering if there is a ‘proper’ way to model this surface so it would follow the curve skeleton exactly.

Hi Chris - if the shape is known to be part of a larger, precisely defined shape like a revolved curve (egg thing) then slicing that is definitely the way to go - but if that is not known, careful input to Patch is a good way.

-Pascal

thx so much for helping me out so quickly Pascal …

so in the end i wasn’t as completely ignorant as i thought :grinning: