SUBD - Rebuild a must have

As I work further with subd I realize the peculiarity of the behavior when using:

  • Insert Point
  • Insert Edge
  • Insert Face

I don’t know if it’s a problem with these commands or with the back-end calculation but edges are created overlapping one another and faces are created with wrong tangent vector.

I wish there was a Rebuild SUBD command that will re-create the current form as closer as possible while allowing the user to define the nuber of edges/faces and control points (or vertices) in a structured way (i.e. also allowing the user to define some parameters like max number of faces at a single point)

Regarding Insert Edge command… I would expect to select one point from one edge and one point from another edge and to create an edge between these two points, alas that’s not at all what’s happening.

I find this very weird and counter-intuitive.

See what I mean:

you can use the _InsertPoint command

do you think I haven’t tried that?

It becomes hecktic very quickly

_InsertPoint command didn’t help build extra edges?

as I said

Hecktic - a meaningless explanation.
Everything works great for me!

to be fair your comments are meaningless, and pulling and pushing a primitive doesn’t mean it works OK! Primitives are just a fraction of what subd is supposed to do.

Take care!

I agree with you, hecktic - a meaningless explanation.
I do not pull or push, and use filters of the vertex.

Take care!

try inserting edges in box mode not smooth… it’s much easier to keep them straight and organized. Fwiw, most of your modeling should be done in box mode, (tab key) using smooth mode only to verify along the way…

subd rule #1 clean box mode= clean smooth mode… messy box mode= whole lotta problems to sort thru with smooth mode.

subd rule #2- use fewer points and faces than you think you need, and pull the surface farther than you think you should… with 1 exception… don’t make your verts or edges cross up in box mode, even though you can, it’ll cause headaches down the road…

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switch to box mode and stitch or delete as needed. It’s much easier to sort this out in box mode. (tab key)

happy modeling!

Thanks, this is what I was missing.

Still though, when converting a complex nurbs surface into subd you don’t get a nice looking box and Rebuild Subd will help a lot

i.e. when converting complex nurbs surface into subd and remove some of the faces to simplify the number of control points… soon you end up with spaghetti looking smooth edges that overlap each other.

totally get where you’re coming from wanting an automagical rebuild (and that would be great, don’t get me wrong) , however the essential KEY to good sub d modeling is managing your topology to be clean and as absolutely simple as humanly possible and that is very rarely achieved with an automated result.

As I teach this I am constantly telling the story of Colin Chapman (head of lotus cars) His philosophy on chassis building (i’m paraphrasing) was keep removing parts until it collapses under it’s own weight… then add the last part you removed back in…

subd’s same thing… you want light light light… keep removing/combining stuff until your model falls apart or you can’t get the shape you want, then undo 1 step…that is likely the place you want to continue modeling from.

any extra faces/edges are just opportunities for inflection and ripples…and that is the exact opposite of why you typically use subd… Think of it like a curve… 3 simple points makes a beautiful corner in nurbs… 20 points in the same corner will inevitably cause lumps and bumps…

hope that helps, happy modeling!


Good one. Yep, that’s what I’m doing, kinda proof of concept to incorporate subd in my current mainly nurbs work process.

first removed all the (then thinking) unnecessary faces of the flat piece. But then I realized what kind of mistake that was. And spent several hours trying to reconstruct the subd mesh.

How about QuadRemesh?

think in 3’s, three edges for a transition- start, middle (crown) and end- break your mode down into curved sections, and try to only have 3 edges for each transition…keep in mind you can steal one edge from a previous curve, (say for an s curve). It’s just like nurbs curves- think of edges like the points in the curve-

Topology IS everything…

Unless your design sucks anyway. :smiling_imp: