Topology strikes again!

Kligan

Hello! 
I'm having difficulties figuring out how to make a proper topology for this shape:


This topology business is very confusing for me for some reason, even after a good deal of experience in modelling overall

I tried to do this:


But as you would imagine, it gives noticeable distortions:


How do I make a correct topology for this? 

musashidan

Correct in relation to what? In hard surface modeling there is no correct or incorrect topology, there is only good topology that bakes(or subdivides) and shades well and uses as little geometry as possible to achieve the result, and bad topology that fails at any of the 3.

What is it you're trying to do? 

Kligan

Well let's assume that this shape would be a reflective surface. In that case, what I did would cause distortions in the reflection, as opposed to more clean topology. That is what I'm trying to figure out.
Generally, it's not a problem since after applying textures to models, little imperfections are simply not noticeable. But what if I wanted to make, let's say, some complex device made of highly reflective surface? That gives me troubles.

musashidan

Well, thats just the nature of polymodeling versus nurbs surfaces for perfect reflections. There are ways to transfer surface shading in sub-d from a proxy mesh, but I only know how to do it in Max and Blender, not Maya.

Are you intending to subdivide?

Kligan

musashidan said:

Well, thats just the nature of polymodeling versus nurbs surfaces for perfect reflections. There are ways to transfer surface shading in sub-d from a proxy mesh, but I only know how to do it in Max and Blender, not Maya.

Are you intending to subdivide?

I never tried NURBS before. I gotta look into that and check some tutorials.

I will be smoothing the model to create highpoly, yes. I usually do that then export that highpoly to Zbrush and add some details, then export what I end up with to xnormal for normalmapping

I just decided to figure out how to do the proper topology all of a sudden... because I usually just skip it like "well I'm gonna fix it in Zbrush anyway". But I mean, having a general understanding how to do clean topology never hurts, right?

So far here's what I ended up with, after some time tweaking things around:


After adding some holding edges and creases, the end result  after smoothing is pretty clean:

Axi5

If I were you, I'd be looking to do this as a two way bend:



There's really nothing special about my topology here:



Reasonable for a high poly but for the low poly you'll want to remove the Sub-D modifier (obviously) and tweak the cage a little bit.

Kligan

Axi5 said:

If I were you, I'd be looking to do this as a two way bend.

Hm... It never occurred to me to do it with deformers Instead I created a sphere and boolean in the ring to it. So I ended up with this puzzle of how to clean the resulting topology.
But I like your idea!

Axi5

Though the way I previously showed you was valid, it leaves something to be desired. If you wanted to do this all on a sphere after all then you could try this approach:

Start with a UV sphere (which has poles to exploit):



Subdivide and remove some geometry near to the poles (you'll want to make sure this is a smooth subdivision, not just adding geometry)



Remove the surrounding geo:



Add an inset on all faces to have a better flow around those corners, also extrude (I added a solidify modifier in Blender):



Subdivide and check it out:



If you want to tighten up those corners then you'll want to further subdivide the edges which will give you:



There will still be a touch of "pinching" around there but it'll be very hard to notice and it can be further ironed out by adding one or two extra subdivisions to those areas.

The key in doing it this way is to take full advantage of the smooth subdivisions, it'll put the edge loops you require in the correct interpolated place so that when it smooths it'll be fairly unnoticeable. Granted, this also requires the use of being able to locally subdivide and I honestly can't remember if Max supports that but I'd be surprised if it didn't, at the very least you could use swift loop + set flow.

Hope it helps