"Dan_The_Man" <dan### [at] hotmailcom> wrote in message 
news:web.43c66fc0e7dfbc3a6d2d290@news.povray.org...
> thanks for your reply

Welcome to it, few and far between as they are.

> yes indeed it is very like a variable star lightcurve. although here the
> change in brightness is cause almost entirely from the shape of the
> asteroid, albedo effects are not as important as the shape.
> all i need is an algorithm to convert the change in intensity relative to
> the phase (over a single period i mite add) to that of the shape of a
> convex hull.
> any ideas??

Thinking this over again...

The two ideas I had in mind before are imperfect for what you're asking... 
from what I can figure anyway.

The first, a variable brightness change across the face of a sphere, 
wouldn't show any shape. I understand you're saying that the asteroid would 
instead most likely need to be modeled with size changes based on the 
orientation the lightcurve is meant to deduce-- or show faces oriented 
toward the observation in a relative size according to brightness.

The second, using an object with size change as it wraps around a central 
point, would cause the smaller sides to be overwhelmed by the larger sides 
unless the distance they are placed outward from the central point happened 
to be farther than the distance the largest sides are in breadth and height. 
In other words, overlap could negate the smallest dimensions or the 
distended shape could look like a chewed donut if seen from above. Hopefully 
I'm describing this in a way that makes sense to you.

Although I'm fresh out of really good ideas at the moment at least I have 
one other suggestion. You might get some more responses by asking at the 
povray.general group since here at povray.newusers the questions and answers 
are usually about basic things concerning POV-Ray itself (not sure how many 
people visit here). Sorry that this didn't occur to me before now, might 
have delayed potential solutions.

I' probably overlooking a simple answer anyway. Also, something I hadn't 
mention before is about the method to get the data into POV. You should be 
able to set up a #read from a file containing the lightcurve values so that 
it is used by an object (or texture, or...?) to create the asteroid model. 
But since my ideas are probably flawed I didn't bother to show an example 
here. Anyhow, you could be checking into file #open or #read found in the 
Help so you can get a grasp of the subject if you don't already know of 
that.

Bob

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