Line and Polygon pixelation at shallow angles

[Cory]

I have noticed this for a while now, and want to understand it
better. When I create any kind of shape in Google Earth, and display
it, it pixelates at shallow viewing angles, become progressively worse
the lower you go, until it is not recognizable anymore. This does not
happen with the items that are pulled from the layers fed from the
Google Earth Server. What is the fundamental difference between these
shapes, and is there a way to mitigate or eliminate the problem?

Cory

[Roman N]

Hi Cory,

When features are set with a clampToGround altitude mode (or
relativeToGround altitude mode with zero altitude), they are rendered
directly onto the same 3D 'surface' of the Earth as terrain imagery.
This invokes some 3D texturing algorithms which can, in some cases,
lead to distortion with some video cards.

One workaround that has proven effective in many cases has been to
force the features off of the Earth's surface by providing a small
altitude (i.e. 10 meters) with an altitude mode of relativeToGround.

Let me know if that works, or if we should try something else.

- Roman

[stillinorbit]

Hi Cory and Roman,

May I add a couple of thoughts to this thread?

Forcing a polygon off the surface does not work in mountainous
terrain. Although the low-angle pixelation goes away when a 10 meter
relative altitude is chosen, the mountains unfortunately "poke up" out
of the polygon, much as mountains might protrude up from a surrounding
glacier. The polygon does not "flow" up and over the mountains at a
constant 10 meter relative distance.

I have noticed though, that when a clamped polygon's display is
changed from "Filled + Outlined" to "Outlined", the polygon's border
suddenly becomes crisp without the pixelation, even at low view
angles. Of course, you don't have the polygon fill, but if all you
need is the polygon outline, this works well.

Stu

[Cory]

I have noticed that in mountainous regions this is much more
pronounced with the polygon becoming completely unrecognizable even at
about 45-60 degree off nadir angles. I guess my real question is, how
can one replicate the look of the data that Google (and other
geodatabase services) serve up? Leaving the polygon on outline only
does work, but I am really big on color coding things, and I like my
areas filled with some transparency. Perhaps the Google Earth
engineers are working on this.

Cory