Topology of circles inside flat faces

Rhav

I have a question regarding a specific topology situation. It may be obvious for some, but i've never received an "Official" answer, so i might as well ask.

Let's say i wanted to model a circle inside a flat face of a videogame prop.

To keep the polycount extremely low i then decide to create an 8 sided circle, like this one.



Pretty simple, but let's say that i don't care about the polycount. I would then create a much smoother circle, but if i stick to the same "modeling technique" form before i would have, in my opinion, something inefficient. Like this one.
I noticed, from many models aound the internet, that people do not create circles like that, but instead create them like this.


Here is my question:
If the object doesn't need to be animated or deformed, and it's sole purpose is to look good to the eye, is the topology of the last example correct and professionally accepted?
Thank you very much for your time.

Neox

in short, yes

but it depends

okidoki

Count the triangles.. 

Mark Dygert

Rhav said:

If the object doesn't need to be animated or deformed, and it's sole purpose is to look good to the eye, is the topology of the last example correct and professionally accepted?

That depends on how the triangles shade or if they create artifacts. Long thin triangles can be problematic for certain types of rendering.

If you have even more edges in your circle then they become longer and thinner, so you might add a ring around the circle and gradually step the number of edges down as it radiates outward.

One other thing to keep in mind is how quads get triangulated. If you export as quads some render engines might flip the "hidden edge" so it goes across the hole in the middle. You can create a visible edge to force it to triangulate properly or export as tris, but it really depends on what you're doing.

Generally you want to have as few verts/tris/edges as possible, unless it causes artifacts or a workflow issue, then add geo to address those issues. 

Rhav

Many, many thanks for the asnwers.

Mark Dygert said:

If you have even more edges in your circle then they become longer and thinner, so you might add a ring around the circle and gradually step the number of edges down as it radiates outward.

Wow, i've never thought of that! I'll definitely try this techique.

Eric Chadwick

Some examples of this technique:
http://wiki.polycount.com/wiki/SphereTopology

gnoop

Rhav said:

Many, many thanks for the asnwers.

Mark Dygert said:

If you have even more edges in your circle then they become longer and thinner, so you might add a ring around the circle and gradually step the number of edges down as it radiates outward.

Wow, i've never thought of that! I'll definitely try this techique.

Even in such cases  it doesn't prevent you from having  perfect shading without any visible pinching  by just editing , transferring vertex normals.   Nobody used  sub-d topology on static meshes  in games  before.  Only on characters.     Now it looks like a must for some uncertain reason. 

Here is an example how with totally "bad" topology  the shading could be perfectly  fine.   

You still  have to be able to do proper topology too  when it really necessary   but in many cases  it's much simpler  to just edit  vertex normals  and  it works better for LODs too  since the shading doesn't depend on supporting edge loops which you going to delete.