thanks for your comments.
Will there also be an option (for those of us comfortable with using your tools) to download a BIN file and make the tiles ourselves, instead of downloading already pre-built tile sets?
As you know, this is far more efficient in terms of time and bandwidth than downloading full tile sets (especially for those of us whose ISP limits our monthly broadband usage!
Certainly, there will always be a collection of links @CM to original imaging data and links for download of my tools in source and binary form.
As to binary VT tile sets one can easily group the levels into hires & "super" - hires sets, just like it is done with the field stars in Stellarium. It is my principal aim to achieve a standardized texture "fidelity"
, defined solely in terms of the original scientific input data and the output from the tools. Actually the DXT (DDS) quality is meanwhile so good that a visual distinction from lossless PNG standard is becoming VERY hard. The DXT rendering performance, however, plays in a completely different "league". Since space missions (Ciclops,...) have now started to target really hires maps (16k,...) it would be a pity to vast the opportunity of corresponding hires visualization !
A universe simulation without state-of-the-art textures is like a hifi set without good loudspeakers
All this has to be seen together with an important Celestia.Sci feature: a loader/unloader for specialized data sets on the fly!
More about this, when the code is ready...
I thought you might be interested in a preview, in front of typical colored Celestia.Sci "galactic background"
Looks very nice. The only *negative* comment I have is that to my eye, some of those galaxies look a little too bright. A bit too much disco perhaps?
The premise of Celestia has always been to show what things would look like to the naked eye. In the interests of Scientific accuracy perhaps they should be toned down a little bit so that they are more "naked eye" than "hubble".
Of course I haven't been on the ISS (yet!
) so I'm no real judge of how bright they would appear to the naked eye when viewed from space, but they just seem a little too bright to me... especially that large one on the right.
Have you enlisted the opinion of any experienced astronauts? Perhaps Rocketman has some contacts?
Actually, I have decided to follow a different, yet much more versatile approach to visualizing (DSO) color in Celestia.Sci.
I have completed already most of the respective new code, and a corresponding "white paper" will come very soon in this department.
. Almost my entire galaxy code in Celestia-1.6. has been rewritten from scratch for this purpose and works nicely already.
We have all learned meanwhile that a consistent, visual
level of displaying the Universe is impossible for quite a number of reasons. Hence visual appearance will not remain to be an aim for Celestia.Sci
, and in fact, would represent a far too narrow framework (see below). In most cases, we only have access to photographic imaging with specific spectral sensitivities. Deriving the visual appearance of objects quantitatively from there is hardly possible in the majority of cases...Yes we could ask some ISS astronauts, but that would solve only a small part of the problem.
Nevertheless, I shall strictly follow a scientific
strategy of visualization that will attempt to display ALL available data --including color information-- in a one-to-one reproducable manner
. Color information (beyond) mere visual impressions represents thoroughly basic knowledge and should therefore NOT be ignored.
Since the standard DSO catalogs do contain precise color information (B-V, ...) this will be rendered in a precise manner as well. I have normalized the galaxy color visualization in Celestia.Sci to the spectral sensitivity and composition of the huge SDSS survey . As you will see soon, the new galaxy appearance in Celestia.Sci is actually quite close to the SDSS imaging. Besides being scientifically well-defined, it also looks quite pretty, actually
There is VERY little resemblance anymore with galaxies in the Celestia-1.6.x distribution. Here is just a quick snapshot comparison for some crowded elliptical galaxy view (Coma cluster
) in SDSS and my new ellipticals. I think it's not too exaggerated to speak of an almost "photo
realistic" rendering. Coma cluster, SDSS photoComa cluster, Celestia.Sci
There will be lots of details soon about how this was achieved. The galaxies shown are pretty dim already (14-17 magnitude) and clearly the dimmest SDSS galaxies are still missing.
Since Celestia.Sci is to also realize my old dream of multi-wavelength astronomical visualization /filtering
, such an extended approach to color appears unavoidable. Astronomy restricted to just the visual band has only remained a comparably SMALL branch of contemporary scientific exploration of the Universe, as you surely know.
seem a little too bright to me... especially that large one on the right.
The "large one at right" is Sagittarius dSph
, a dwarf galaxy about to collide with the MilkyWay that was discovered only very recently. Due to the closeness to the light of our galaxy, there is virtually NO usable photographic imaging yet. But it's known to be VERY bright: 3.8 mag
. The surface brightness may be low, however. Anyway, we don't know how bright that dwarf looks like AWAY from the canonical perspective, as e.g. on my above pictures.