Hi All

I want to create some animations of meditation visualisations, which include
visualising the Sun and the (full) Moon. I imagine that they each appear as
bright objects with some sort of aura or light streaming from their surface
for a short distance. The point is to also make them bright without looking
flat or "hurting your eyes" like looking at the sun would actually do. They
need to be postioned in a dark but not necessarily black background.

As a newbie, I'm having trouble translating what I can imagine into some
concrete reality (the usual problem I guess). For example I don't even have
an idea about how to create the appropriate color for each object. Sure I
could guess a yellowish color for the Sun, or a whitish color for the moon,
but how could I apply a color to give the objects some body, so they don't
just look like flat balls of color. Can anyone suggest how to do this for a
start.

Further, if anyone can point me to some examples of say, a full moon shining
in a clear night sky, or the sun shining in a bright blue sky, then this
might help me get where I want to go. Thanks.

Be Well and Happy Always

Chris

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On Tue, 25 Jun 2002 02:46:53 -0400, Chris Friedl wrote:

> Further, if anyone can point me to some examples of say, a full moon
> shining in a clear night sky, or the sun shining in a bright blue sky,
> then this might help me get where I want to go. Thanks.

A tip on rendering the Moon as seen from the Earth:

"For example the lunar surface has a [bidirectional reflectivity] that
peaks in the direction of incidence [SIEG81].  During a full moon, when
the sun, earth, and moon are nearly in line, this accounts for why the
moon appears as a disk of roughly uniform intensity.  If the moon had a
Lambertian surface, it would, instead, reflect more light at its center
than at its sides."

Foley, van Dam, Feiner, and Hughes, Computer Graphics: Principles and
Practice, second edition, p. 763

The [SIEG81] reference is to Siegel, R. and J Howell, Thermal Radiation
Heat Transfer, second edition, Hemisphere, Washington, DC, 1981

Ignore this, and the moon will look odd.

-Mark Gordon

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