- [Instructor] Want to talk about level of detail
for polygon objects such as this monitor stand.
Level of detail is sometimes confused with fidelity,
but they're not the same thing.
Fidelity refers to how well a 3-D model,
resembles a real object,
but level of detail simply refers
to the density of that model.
How many sub-objects or components does it have?
And adding more components or sub-objects such as polygons,
does not necessarily improve the fidelity.
Let's take a look at this.
I've got my monitor stand selected.
I'll go to the Modify panel,
and we have a box that's being tapered and bent.
Let's go to the box parameters.
And as we say previously, we can change
up the length segments to improve the curvature
along the length of the box.
Currently, I've got a value of 40.
And zoomed in pretty tight here in the left view,
we can see it's kind of segmented.
If we reduce the length segments, it gets more blocky.
If we increase the length segments,
it gets smoother and rounder.
Set that back to a value of 40.
So, in the case of the length segments,
changing the level
of detail definitely does affect the fidelity.
But in the case of these width and height segments,
it's actually not going to improve the fidelity,
and that's because the object has no curvature
in those dimensions.
So to illustrate, let's get in closer
in the perspective you control alt in middle mouse,
increase the width segments,
and we start to see more polygons.
It's increased the level of detail,
but it has not increased the fidelity.
And actually, if we rendered this object
with a width segments of 10 versus a width segments of one,
we wouldn't be able to tell the difference there.
And that's because there's no curvature here.
We're just unnecessarily subdividing in that dimension,
and it's not improving the fidelity at all.
We could bring width down back to one.
Same with height, if we increase the height segments
up to let's say five or something,
get in really close on the edge of that model,
and we can see we've increased the level of detail,
but again, we haven't increased the fidelity.
We're just adding more polygons for no reason,
and it's very likely going to bog down our system.
So, I'll bring my height segments back
down to a value of one.
So that's really a good rule of thumb.
If a model is flat in a certain dimension,
then you don't want to unnecessarily segment it
in that dimension.
You only want to add segments where you need
to resolve some curvature on the model.
Let's also look at reading out our level of detail
in terms of the number of polygons on the object.
And that's done in the viewports,
and we can do that with a keyboard command.
So give focus to the perspective view.
And then, press the seven key on your keyboard.
And we'll see statistics.
And we see that it reads out almost 14 thousand polygons.
But this is the readout for the entire scene.
And that's helpful, but I'm more interested
in the number of polygons on the selected object.
To get that on my screen, I'll need to go
into my viewport configuration dialog.
So go into the general viewport menu,
which is the plus sign.
Click on that plus sign,
and then, choose Configure Viewports.
In the viewports configuration dialog,
go over to the statistics tab,
and in the set-up area,
enable Total plus Selection.
Turn that on, and click okay.
Now, we see the number of polygons for the selected object.
I can pan over with the middle mouse.
So the monitor stand currently has about 300 polygons.
If I increase the number of width segments,
you'll see I'm able
to drastically increase the polygon count.
If I set my width segments to something like 20,
I'm going to be increasing the level
of detail by a factor of 10.
But it's not going to be increasing the fidelity at all.
Okay, so, I'm bringing this width segments back
down to a value of one.
And let's get a good resolution to our curvature here.
Let's set our length segments to a value of 100,
and we land at a level of detail of about 800 polygons.
We've pretty much optimized the level of detail
and the fidelity for this monitor stand object.
Let's turn our statistics back off again.
Right click in that perspective viewport
to give it focus and take focus off
of anything else we might've been working on.
And then, press the seven key on the keyboard.
And that is how to adjust level of detail
and fidelity by adjusting the segments
of a parametric primitive such as the box.