32k Earth-Clouds Experiments

[Guest]

It's 1.3.1final. Have you got the vt folder in the medres textures folder(not in extras)?

[selden]

Jack,

Did you try setting the CloudSpeed to 0?

If the clouds don't have to move, then more features are available, like higher resolution, etc. Don Edwards discovered and made a posting about this feature a while ago.

[sombrehombre]

I haven't even started looking at the 43k MODIS cloud set - that's
why I questioned about the poles. At present they're just a gleam in
my eye. 16k clouds would only make sense as VTs - DXT3 is out of the
question at that scale, and as of yet, I don't have any experience making
VTs.

If anyone knows of a thread/website that has useful scripts for VT
creation I'd appreciate it - especially if they can run as batch files (with
GnuWin32 NetPBM under standard Windows). Most of these threads
must be ancient history around here.

Note that I didn't suggest making the product tiles 8k (isn't 512x512 the
accepted universal standard?), just that you might have an easier time
doing editing at 8k x 8k (8 times) rather than 4k x 4k (32 times), before
slicing up for VTs.

I have 512 M memory, and GIMP manipulations at 8k x 8k are
doable (but slow) - thats what I used on the Moon and my version
of Blue Marble for Orbiter. Once images were edited, bumped, or
recolored, I used the GnuWin32 NetPBM library for merging, scaling,
masking, and compositing - GIMP would die at larger than 8k x 8k.

I couldn't use DX3 tiles at 4k as you do, as my 64M Radeon card can
only render up to 2k. Maybe this accounts for the framerate hit you
are getting with 4k.

[selden]

Darryl,

Fridger wrote a shell script to invoke the ImageMagick command line utility "convert" to do the slicing-and-dicing. I put links to that and to the thread where he announced it at the end of the VT section of my textures page at http://www.lns.cornell.edu/~seb/celestia/textures.html#2.5.5

Now if Bob would just hurry up and get his "VTs for Dummies" written, I'll add a link to that, too!

[Bob Hegwood]

Now if Bob would just hurry up and get his "VTs for Dummies" written, I'll add a link to that, too!

Selden,

Gimme a break willya? It took me about two weeks just to understand the things in the first place.
If it hadn't been for the excellent (and patient) advice I received from Toti and Malcom, I'd *still*
be trying to figure out what the hell they were.

BTW, the correct title will be "Virtual Textures For The Brain-Dead!" I believe that
I have the experience now to qualify that title. Yes?

I'd also like to thank YOU and Dr. Schrempp for the helpful advice and, of course Fridger's script. Now
that I know how to use the thing, it's a beautiful addition to my Celestial Toolbox.

Take care, Bob

[wcomer]

These lines are caused in the creation process by bump mapping each tile separately.This is done to give the clouds some better depth and also to make them more opaque etc.. I was going to fix it by just trimming off some pixels on each tile and resizing but then the time issue rears its ugly head. To me they are intensely annoying but if people thought they could put up with it i might just and release it anyway.(of course this all depends on if college is willing to give me any more space) So let me know what ye's think.

As I understand it you are using an algorithm something like this:
1) tiling the cloud maps into fixed tiles (say 1k x 1k)
2) creating bump/normal maps tiles from the cloud map tiles
3) adding shading to the original cloud map tiles via the bump/normal map tiles.

Instead you might try doing the following:
1) create overlapping tiles of the cloud maps (say 1k+10 x 1k+10)
2) same as before
3) same as before
4) crop off the 10 pixel borders.

I believe this method will eliminate those lines.

[DBrady]

Excellent. Thanks wcomer. Thats one of those simple solutions that makes you bang you head wondering why you didnt think of it first!
I am just using the gimp bumpmap filter and layering clouds on top but the solution still applies. Thanks again.

[JackHiggins]

Did you try setting the CloudSpeed to 0?

This was the first thing I made sure of, since I didn't want to look stupid later on, if this turned out to cause problems for me...

It's 1.3.1final. Have you got the vt folder in the medres textures folder(not in extras)?

No, I didn't. That makes them work perfectly now! Thanks!

In testing them out, I came across this rather stunning view- thought i'd share it with the rest of you...




(This is a crappy jpeg version btw- if anyone would like a better copy just email me and i'll send it on..)