Bill Hails wrote:

> H Frank, thanks for your comments.
> 

> 
>> Hi Bill!
>> 
>> Looks good, but the lighting needs improvement: your sun is an
>> extended light source, so
>>  - no shadows of the bars carrying the planets should be visible
>>    on the desk
> 
> I agree, but an area light introduces too vague a shadow on the
> rings of saturn. I'd pinned my hopes on a parallel light, but that
> requires a pont_at statement :-(
> I was trying to avoid letting the planets look too much "in the room"
> as opposed to "in space", the harsh shadows on Saturn's rings
> help there, I think.
> 
>>  - the disk below the sun (on the desk) should be free of shadows
>>  - the shadow of the book in the foreground should be very soft
>>  - more than a half sphere of the planets should be lit (esp. Venus)
> 
> same point vs area light issue, maybe a fairly tight area light would do
> it.
> 

I was just paging through the manual and found 6.5.8 "Light Groups"
It looks to be exactly what I need - separate lighting for the planets.

I'm constantly amazed at the maturity of POV-Ray, it's like every
problem I have has already been solved somewhere!

>[...]
>>    Sputnik
> 

-- 
Bill Hails

Post a reply to this message

It has definitely improved.  I really like the prominances on the Sun and I
agree that the rings work very well.

I'm no expert, but here are some things I'd try if I were you:
- Change the number and position of the prominances.  The more I look at the
Sun in this picture, the more the prominances seem imbalanced somehow.
- Change that innermost planet.  It doesn't look like any planet in our
system.
It's too big and shiny to be Mercury and too small and grey to be Venus.
- That sun appears to be the only light in that room, so perhaps the room
should appear darker.  If the room is darker and the dark sides of the
planets show less ambient light, it might improve the look of the room.
Either that or add some other lights.
- Is the sun already an area light?  I think if you made it an area light
approximately the size of Earth and turned "orient" on there might be some
improvement.
- Increase the apparent detail in the wall texture and maybe change the
finish.  Right now it looks like some sort of plastic veneer.
- The far part of the table should appear grayer and less shiny than the
near part.  That's because the surface over there is being viewed at a more
oblique angle, which means there will be a greater density of dust
particles along the line of sight.  I wonder if a thin layer of scattering
media would do the trick.

Just so you know, I don't criticize when I don't like a piece.  (I often
don't criticize even when I do, however.  Laziness.)

Bill Hails wrote:
>I've been fiddling with this old pic for over a month now,
>and I need to start something new, but I thought somebody
>might like it.

Post a reply to this message

Thanks for your comments, and sorry I haven't been keeping a close eye
on this thread :-)
I've been working on it most of my spare time since I last posted, expect
an update soon.

Mack Tuesday wrote:
> It has definitely improved.  I really like the prominances on the Sun and
> I agree that the rings work very well.
> 
> I'm no expert, but here are some things I'd try if I were you:
> - Change the number and position of the prominances.  The more I look at
> the Sun in this picture, the more the prominances seem imbalanced somehow.

I've rotated the sun slightly (15*y). That improves the balance.

> - Change that innermost planet.  It doesn't look like any planet in our
> system.
> It's too big and shiny to be Mercury and too small and grey to be Venus.

dunno, I kind of like it (It's meant to be Venus). I'm not aiming for
scientific accuracy, just an impression.

> - That sun appears to be the only light in that room, so perhaps the room
> should appear darker.  If the room is darker and the dark sides of the
> planets show less ambient light, it might improve the look of the room.
> Either that or add some other lights.

I've gone round and round with the lighting, I hope I've fixed things.

> - Is the sun already an area light?  I think if you made it an area light
> approximately the size of Earth and turned "orient" on there might be some
> improvement.

For my final render I'm using a circular area light the same size as the 
sun, with orient, but it changes the render time from 8-9 hours to 4-5 days 
at 1920x1440 so I'm fixing other stuff before I do that again.

I've also made each planetary body its own light_group with a parallel
light at the sun's center, and fixed up the radiosity.

> - Increase the apparent detail in the wall texture and maybe change the
> finish.  Right now it looks like some sort of plastic veneer.

Terracotta, terracotta :-) Hopefully the lighting fixes will improve that.

> - The far part of the table should appear grayer and less shiny than the
> near part.  That's because the surface over there is being viewed at a
> more oblique angle, which means there will be a greater density of dust
> particles along the line of sight.  I wonder if a thin layer of scattering
> media would do the trick.

That's where I'm at right now, exchanging a semi-transparent disc for a 
cylinder with media, I'm also adding smudges from the book-hole to the 
book, and increasing the density of the dust a bit, to make the marks a bit 
more obvious.

> Just so you know, I don't criticize when I don't like a piece.  (I often
> don't criticize even when I do, however.  Laziness.)

Thanks!  I've been working on this since June, off and on (mostly on since I 
last posted), hopefully the end result will have been worth it.

> Bill Hails wrote:
>>I've been fiddling with this old pic for over a month now,
>>and I need to start something new, but I thought somebody
>>might like it.

-- 
Bill Hails

Post a reply to this message