N-gons or Stars - best practices / pro - cons

[Tom_P]

i have a more general question about “best practices” regarding topology for sub-D.
maybe @theoutside Kyle know more about this ?

(left)
My former subdivision practices everything was quads. And carefully placed star-points. (left)

(middle)
Rhinos Sub-D seam to have nice Surfaces also if the star-points are at positions, where the principal curvatures are convex and concave (+/-). Any disadvantage for this ? ( middle )

(right)
an alternative seam to be n-gons.
@theoutside Kyle uses them for example in this video

d://cZCHG4NxmeQim3c5HLUwsgLZozC.3dm) (3.3 MB)

the _toNurbs result (second row in the back ) of the last approach is unexpected. does the _toNurbs command do some surface-Merging in the background ?

thanks for your opinions / thoughts / advices. kind regards -tom

[martinsiegrist]

@Tom_P

(middle)
Rhinos Sub-D seam to have nice Surfaces also if the star-points are at positions, where the principal curvatures are convex and concave (+/-).

…this is what I’m usually trying to achieve.

I don’t see an advantage having an Ngon or triangular face in there.

[Michael_Pryor (ekim)]

Better to bring that star point down one loop so the star pinch isn’t on the curvature. Will look better for reflections.

In this pic you will also change the edges on the flat part obviously, too lazy to draw, would follow the one I circled green in @Tom_ image.

[diff-arch]

Quads are for humans, tris are for the GPU, and n-gons are for n00bs.

Check this out:

Archive

[Michael_Pryor (ekim)]

Truth! Quads are really just for UV mapping texture stuff (which is kind of getting gradually axed by procedural texturing anyway), render engines, printers, etc etc all convert to tri anyway whether we like it or not.

[theoutside (Kyle Houchens)]

I’d love to say I have a “system” for topology. My only system really is “use less to do more” I try very hard to constantly take away edges until the model falls apart then put that last edge back in. Since every model is different and has a different expected outcome and use, the layout and topo could be different on every one.

This chart is useful to get out of trouble spots, (below) but honestly Rhino Subd is so robust and forgiving, you can do just about anything you want, as long as it gets to you the outcome you are looking for- Purists will argue with me, but I worry more about if my design looks like what I have in my head, and less about the layout…

[RodolfoSantos]

@theoutside

Purists will argue with me…

…inevitably.

Regards
Rodolfo Santos