Am 02.10.2015 um 01:06 schrieb David Given:

>> Uh... wait - sky? ocean?
>>
>> We are talking about the moon, as in, /our/ moon, right?
> 
> Oh, absolutely.

Hm... maybe you'd be faster off rendering it in a realistic fashion then ;)

JK.

> The jitter has helped with the banding, at the expense of some noise.
> (The dark shadow in the dawn picture should be there; it's the planet's
> shadow cast through the atmosphere. But it shouldn't be that grainy.)

Here's where one of the drawbacks of method 3 surfaces: You have to
specify an absolute threshold, but in dark regions our eyes are more
sensitive to absolute differences. So to reduce the noise there, you
also have to throw more computing power at the brighter regions where
it's not really necessary.

IIRC adaptive focal blur is based on the relative error, so that might
be a more efficient way of getting more oversampling in the darker regions.

> Unfortunately, UberPOV is largely out of the question, because I'm using
> a custom patched POV anyway. (The DLL code.)

Sounds like it's time I got me a fresh batch of round tuits and
integrated the most recent POV-Ray changes into UberPOV. I presume that
would allow you to integrate your custom patch into UberPOV as well.

> So I'm going to have to
> start playing with aa_level and aa_threshold, right? Although I hadn't
> thought of fiddling with focal blur. I'll have to try that.

The focal blur algorithm includes the best general adaptive oversampling
mechanism that is available in official POV-Ray 3.7, so the idea is to
introduce a /tiny/ bit of focal blur, in order to make that mechanism
kick in.

> Did you know the moon's gravitation field is
> lumpy? The lunar ocean varies in height by about a kilometre.)

Well, I'm quite the "lunatic", but here's a fact that's news even to me.

Another reason to not flood the moon: You never know where the
shorelines will be ;)

Did you also factor in the gravitational pull from earth? That must be
"quite an attraction", and may even cause noticeable monthly tides -
despite the moon being tidally locked to the earth - due to libration as
well as variation in the distance to earth.

Then again, thinking about it, those tides must "drown" in immense
semi-monthly tides rolling around the moon due to the sun's
gravitational pull, given how low the moon's own gravitation is.

Post a reply to this message