Celestia Forums

t00fri,
I tend to disagree with you on this matter. After making some 32k tiles, and seeing them in action, i can only presume that you are against using anything over 4k for a spec map purely for memory reasons. If so, you are underestimating the improvement in viewing quality achieved by such maps. I think a picture or two speaks louder then words can so...




In the above picture you can clearly see the distinction between the 32k(bottom left) and 4k(topright).

In my eyes the 32k is far, FAR superior to the 4k - for lakes AND land edges.
I do agree though that a 32k normal map should be first priority, after a 32k base map, but a spec map runs a close second.

I must agree! those pictures look woderfull!!!

DBrady,

you almost convinced me;-). You images do look nice! But I feel that at least my engine will run out of steam...

Bye Fridger

Yes, we do really need a 32k virtualtex specmap. (but normalmap first!) DBrady, those pictures look fantastic!!

Fridger wrote:you almost convinced me;-). Your images do look nice! But I feel that at least my engine will run out of steam with 32k base map, 32k normal map, 16 nightlights and 32k spec's...

I'm willing to try it out though...!! 32k nightlights would be great too- where's your program for making virtual tex tiles t00fri? I can't seem to find it anywhere...

JackHiggins wrote:Yes, we do really need a 32k virtualtex specmap. (but normalmap first!) DBrady, those pictures look fantastic!!

Fridger wrote:you almost convinced me;-). Your images do look nice! But I feel that at least my engine will run out of steam with 32k base map, 32k normal map, 16 nightlights and 32k spec's...

I'm willing to try it out though...!! 32k nightlights would be great too- where's your program for making virtual tex tiles t00fri? I can't seem to find it anywhere...

Too bad;-)

Here it is...

http://www.shatters.net/~t00fri/virtualtex

Bye Fridger

Aww I thought it was an exe file! I have no software for compiling something like this either... Hm.. Guess i'll just have to wait so...

Hi DBrady,

That's exact what I mean. I could present similar pictures with the same result. Further it will be needed a base VT512 specular map for my high level tiles.

Bye Jens

Very nice Dbrady! I agree my old 8k spec map is not good enough for the resolutions we see today... Unfortunately the GIS web site I used to make it is shut down. Where did you get your data?

Buzz,
At the moment i just cut up the 32k texture into manageable 8k sizes. Load each in gimp then...
1. select by colour 15%- click on oceans
2. invert selection
3. cut
4. image/ mode/ grayscale
5. colors/ invert
6. save

Its quite a crude method but is all i could think of. I have thought about trying to extract the nodata value from the Globe DEM's and making one that way - but it will take a while to see if thats possible.

Are there good reasons for not using DBrady's method? Please provides pro's and con's.

If this seems like a reasonable approach, I can use GIMP's CLI to put together a complete 32k spec map, which will likely compress very well. Hopefully Mario would be willing to host it.

While on the subject of spec maps. Do they have to be black and white, or is it possible to use grey scales? The reason is that ice is a nearely perfect reflector. Desert sands should cause noticable specular effects but not as strong as ice or water. I've seen shuttle photos of the specular effects of the swamps of sudan as well, but again this isn't as strong as ocean water, and doesn't have any clearly defined border. There is quite a bit which could be worked in into a a spec map; I'm sure the celestia community could think of many more.
Walton

I guess a 32k spec map wil be a virtual texture...right? If so, how do we implement it and when will it be ready....Looks fantastic!

To be honest...I'd rather have the spec map than the 'normal' map...I'm having a lot of problems getting any sort of bump map to work properly. I know...buy a new computer...blah...blah. (Ihave a slight bias towards the water...I've always been a bit bit fishy!).

I'm very happy with the way it's looking so far...I'm sure you guys know what you're doing and am looking forward to the latest releases!

bh.

JackHiggins wrote:Aww I thought it was an exe file! I have no software for compiling something like this either... Hm.. Guess i'll just have to wait so...

Jack,

not at all. Just install besides ImageMagic (Q8 version) for Windows, Cygwin for Windows via a trivial setup program , including the zsh ("z-shell") and you are ready to go. Put virtualtex into the /usr/local/bin directory of the Cygwin "unix" tree.

ImageMagic is good to have anyhow. It's a very powerful image manipulation package...

Bye Fridger

Hi,

Here is another 128k example with 128k spec map compared with the 32k BlueMarble map with 8k spec map.

Bye Jens

Beautifull view!

Blimey...stunning...I really do think we may see some waves soon. Now, what are those Islands called again!

Regards...bh.

Hi DBrady,

Thanks for explaining your approach. It really works out very well! I have tried it too before using other methods but was not very succesful.

I would not recommend to use elevation data, as there are many dry areas on earth that are well below sea level, for example a substantial part of the country I live in, including the location where this message was typed! Other examples: death valley, a part of Egypt, the area around the dead sea and I am sure there ar more.

As far as I know, the area around the Dead Sea its 500m aunder the sea level.

Hi all,

I went with DBrady's idea but took a different avenue. Instead I.
1. select by color 20% - click on oceans (I think 20% captures the landlocked water more accurately without many mistakes.)
2. image/mode/grayscale - convert to greyscale.
3. imade/colors/invert - invert the water color.
4. image/colors/levels set input level to 0, 0.40, 255 - change the color levels to darken the land masses.
5. save

Notice that I don't cut the landmasses out. Instead I have a spec map that has high reflectivity for bright parts of the landmass. The modification of the color levels causes darkens all but the lightes part of the landmasses. The end result is that snow and ice are highly reflective; desert regions tend to be of moderate refectivity, with a few exceptions; while most everything else takes on a very mild reflectivity that is probably more realistic than having none at all. Here is a sequence as the sun passes over australia.






Here is a shot without the specular map. I took shots without at all four intervals but cannot distinguish between them.



Here is a reduced .png of the spec map relevant to these shots.



Currently these are as 8 8kx8k .png. I need to convert them to a full virtual texture of 512x512 .dxt's, but first I'd like to get feedback as to whether this is an appropriate approach to spec maps.

Walton,

with my due respect, but I think these spec images look rather horrible (sorry for my straight "Hamburg manners";-))

Or did I overlook something crucial?

Bye Fridger