Moon

[bagnell]

Adds the Earth's moon.

[mramato]

Nice. The moon seems to elongate as it gets to the edges of the view. Is this because of the fov? Or is something else going on. I'm not saying it's a bug, I just don't understand why it happens.

[pjcozzi]

Expand a bit. We also added Iau2000Orientation.ComputeMoon.

[pjcozzi]

Do you get this failure in Firefox?

Core/IauOrientationAxes compute ICRF to Moon Fixed. (show summary)
Expected { 0 : 0.784227052091917, 1 : -0.6200619152508556, 2 : -0.022608671404182445, 3 : 0.5578471124601639, 4 : 0.7205566654668133, 5 : -0.41183090094261243, 6 : 0.27165148607559436, 7 : 0.3103567513471994, 8 : 0.9109797785934294 } to equal { 0 : 0.784227052091917, 1 : -0.6200619152508556, 2 : -0.022608671404182448, 3 : 0.5578471124601639, 4 : 0.7205566654668133, 5 : -0.41183090094261243, 6 : 0.27165148607559436, 7 : 0.3103567513471994, 8 : 0.9109797785934294 }.

[pjcozzi]

This doesn't use JulianDate. It also won't use Iau2000Orientation after some changes.

[pjcozzi]

@bagnell let's add showLabel properties to the sun and the moon (with the correct eye offsets) so they are easier to spot. It's probably best for each to have their own LabelCollection, and that it can return the Label so users can tweak the font, etc. Do this as a separate PR if you want.

I also encouraged @emackey to tweak the default FOV so we can see if we like it.

[emackey]

If you zoom way out from the Earth, and pan the view to put the Moon in the center of the screen and slowly zoom in, you won't see the Moon occlude the Earth even though it is in front of it. Can this be fixed?

[pjcozzi]

Code looks good. Let's see if we can fix the z-order before merging.

[bagnell]

@pjcozzi This is ready for another review.

[mramato]

Do we have a higher-res moon for the cesium-assets repository? I'd like to use this branch in an upcoming demo.

[pjcozzi]

@mramato see https://github.com/AnalyticalGraphicsInc/cesium-assets/tree/master/textures

[pjcozzi]

Want to merge #1194 and use the new ellipsoid options here?

[bagnell]

How does this affect multi-frustum now that we need to include the moon?

With the current far-to-near ratio, the maximum number of frustums I've seen is 3. For horizon views with the moon visible, the number of frustums is 3 and it is the same if the moon is not shown.

How many more commands overlap frustums from different views?

For views centered around the Earth, it will only add one command for the last frustum. If the view is centered on the moon, then the number of commands is one or two where it can overlap the first two frustums.

[pjcozzi]

Is this ready?

[bagnell]

@pjcozzi This is ready.

[pjcozzi]

Do you get this test failure?

[bagnell]

Yes, I forgot to update the tests. They're fixed now.

[pjcozzi]

Looks good. We'll need do the labels at some point. #1218