Wall width x cylinder radius = Hollow percentage (or similar math?)

[steph Arnott]

If you want to be really pedantic, there is no such thing as a circle, it is just smaller and smaller straight lines and intersections.

[Dora Gustafson]

24 sided polygon? As the distance increase it will have even fewer sides

The number is diffferent for each defined LOD

[steph Arnott]

I did not know that, so the larger it get the more degraded it becomes?

ADDED: Would do, but then I really never bothered worrying about it, :smileyvery-happy:

[Drongle McMahon]

... so the larger it get the more degraded it becomes?

In the sense that the flat surfaces are larger, yes. The high LOD* prim cylinder is always 24 sided, whatever its size (the one in my picture was 50m diameter). Then of course, the smaller a cylinder is, the sooner it will switch to lower LODs as the camera moves away. It goes from 24 to 15 to 9 to 6 sides, as shown in the picture (taken inworld in wireframe view with surface patch, water and sky turner off, adjusting renderVolumeLODFactor to switch LODs).  Sothe accuracy becomes less again, but it doesn't matter because you are too far away to see the difference when the LOD switches.

* level of detail.

[Kwakkelde Kwak]

I can be even more pedantic.

Of course there's a real circle. The only thing is, you can't calculate its circumference exactly. When you use a floating value of pi, you calculate a circumference by turning the circle into an endless amount of lines. Pi isn't something you need to define a circle though, you use the radius for that. The distance from any point on the circle to the centre is exactly the same. This wouldn't be the case if a circle wasn't perfectly circular.

[Coby Foden]

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steph Arnott wrote:

If you want to be really pedantic, there is no such thing as a circle, it is just smaller and smaller straight lines and intersections.

---

[Pedantic mode on...]

Definition:

"A circle can be defined as the curve traced out by a point that moves so that its distance from a given point is constant."

In polygonal softwares we just imitate circle with straight lines - but that polygon, however many straight lines it consists of, is not a circle at all. By definition a circle is a curve - it has no straight lines.

 

Example of a perfect circle - no straight lines: :matte-motes-wink:

[... switching off pedantic mode.]

:matte-motes-big-grin:

 

[Edit]

Spelling corrected (swithcing --> switching). I need new spectacles!  :smileyindifferent:

[Rolig Loon]

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Coby Foden wrote:

[ .... ]

In polygonal softwares

we just imitate circle with straight lines

- but that polygon, however many straight lines it consists of, is not a circle at all. By definition a circle is a curve - it has no straight lines.

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 I think that's pretty clearly what Steph had in mind, given the context.  :smileywink:

In any case, the message to the OP is reasonably clear.  There's no point in getting obsessive about calculating the precise wall thickness of a cylinder in SL.  There are too many good reasons why that's wasted effort.

[Madelaine McMasters]

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Coby Foden wrote:

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steph Arnott wrote:

If you want to be really pedantic, there is no such thing as a circle, it is just smaller and smaller straight lines and intersections.

---

[Pedantic mode on...]

Definition:

"A circle can be defined as the

curve

traced out by a point that moves so that its distance from a given point is constant."

In polygonal softwares we just imitate circle with straight lines - but that polygon, however many straight lines it consists of, is not a circle at all. By definition a circle is a curve - it has no straight lines.

 

Example of a perfect circle - no straight lines: :matte-motes-wink:

[... swithcing off pedantic mode.]

:matte-motes-big-grin:

---

[Pedantic mode on...]

Curves can't actually exist in the real world because there are no (or if there are, we fight them like crazy) physical infinities. There are no straight lines or intersections either, since there are no points, unless you count that singularity thing from which everything emerged. But that's only one point, so still... no lines, no intersections!

So, I propose that, every time we use a mathematical concept to describe reality, we preface it with "sorta", a contraction of "sort of" which means "approximately".

[Pedantic mode sorta off...]

;-)