Some informations about textures (little FAQ)

[BobHegwood]

My Celestia is loading textures from the lores folder over the ones in the medres. How do I solve this?

Me again...
Try pressing SHIFT and the letter R to raise the texture resolutions. Will cause Celestia to pull textures from medres if you are currently pulling from lores, and will cause it to pull from hires if you are currently pulling from medres.

You can also get around ALL of this mess simply by placing all of the textures you wish to use in the textures\medres folder, and then deleting all of the textures in the other two folders. This is not recommended, but this is how I have been using Celestia since I started using it long ago, in a Galaxy far, far away.
Thanks, Brain-Dead

[MBV]

I didn't know about that command, thank you, it apparently resolved the question.

You can also get around ALL of this mess simply by placing all of the textures you wish to use in the textures\medres folder, and then deleting all of the textures in the other two folders. This is not recommended, but this is how I have been using Celestia since I started using it long ago, in a Galaxy far, far away.
Thanks, Brain-Dead

That's what I'm probably going to do. It's quite easier.

[Yodarick]

I am new to Celestia and am downloading the abundance of add ons, my thanks to all the contributors.

I am a Mac users and I have one question regarding textures. When I add them to the hires/medres folders do I keep them in their subfolders or move them all to the main folder?
ie: hires > venus > level 3 > tx_0_0.png or hires > tx_0_0.png

Thanks for the help

[cartrite]

I am new to Celestia and am downloading the abundance of add ons, my thanks to all the contributors.

I am a Mac users and I have one question regarding textures. When I add them to the hires/medres folders do I keep them in their subfolders or move them all to the main folder?
ie: hires > venus > level 3 > tx_0_0.png or hires > tx_0_0.png

Thanks for the help

Every level has similar file names and many will overwrite each other if you place all of them in one folder. So you should keep them in their subfolders. That is where Celestia will look for the file. You should actually leave everything as it is. If something is wrong, then contact the author of the texture set you downloaded.

Actually, regarding the texture set you downloaded, look for a read me file or install file or anything that will instruct you how to install it. With most addons, they are placed in the extras folder. But Mac does things a bit different I think and I don't have a mac so.........
But you should leave tx files in their subfolders.
cartrite

[MariaTom]

MY ANSVER AND ALL ABOUT IT WAS MOVED TO

http://www.shatters.net/forum/viewtopic.php?p=17003#17003

The precision of the information given by this tool is really impressive. With it, you will no longer have to rely on meteorological services that have less credibility day after day.


http://downloads.phpnuke.org/en/version ... -z-b-x.htm

[Vorthon]

I'm having a problem with an add-on I'm creating... whenever I use both a bumpmap and a specmap, I get these horrible rendering artefacts near the coastlines on worlds with oceans. they appear as blocky areas of lower reflectivity than the rest of the oceans. I've tried making the oceans completely flat in the bumpmap, but I still get the effect. Any idea what's causing it?

[Spaceman Spiff]

It's a sign of inconsistent texture image resolution.

Example: If your bumpmap is 8192?4096 pixels but your surface map (which contains the specular map in its alpha channel, right?) is only 2048?1024 pixels, then the specular map pixels appear four times as wide as the bump map pixels. (I set up the example this way round because your secription suggests a coarser specular map.)

Is that it?

Spiff.

[Vorthon]

I checked, and they're all 1024x512. anything else that could cause it?

[t00fri]

It's a sign of inconsistent texture image resolution.

Example: If your bumpmap is 8192?4096 pixels but your surface map (which contains the specular map in its alpha channel, right?) is only 2048?1024 pixels, then the specular map pixels appear four times as wide as the bump map pixels. (I set up the example this way round because your secription suggests a coarser specular map.)

Is that it?

Spiff.

No .

I know this phenomenon very well, but I hate to guess more or less blindly.

Therefore:
Before any more explicit discussion, Vorthon first needs to specify his settings in much more detail:

--Was DXT (=dds) format used? If yes, which one? Which tool?
--Other lossy formats used or PNG?
--Was the specular mask in the alpha channel or separate?

Usually the cause is insufficient smoothness of the bumpmap/normalmap combined with the enhancing effect of specular light! Specular light can strongly amplify the effects of bumpmaps/normalmaps. The physical reason might well be obvious. Otherwise I could explain it of course.

This mechanism can have both positive and negative effects. Here is a mostly positive one first:

The image illustrates dramatically the strong amplification by leaving just a little specular "rest light" in the alpha channel, when applying the normalmap to a hires patch of my 32k Mars texture.

(but also note the "wet plastic" appearance that usually comes with this technique)

The same effect can also give rise to those familiar dark blocking artefacts along coastal boundaries if the normal map is not smooth enough.( Note that all bumpmaps are internally converted into normalmaps)

But first I need more info.

Fridger

[Vorthon]

I used a jpeg file, with average detail preservation. I also applied a slight gaussian blur before saving . Would that affect anything? I'm using adobe photoshop elements 2.0 for the editing... I know, a little archaic, but adobe photoshop 5.0 limited edition sometimes crashes when I'm in the middle of something, and anyways, I'm too lazy (and cheap) to go out and get a newer version.

Not meaning to be sarcastic, but is this colour of text any less painful to look at? I want to use a greenish font, but don't want to upset people. The reason I use bold font is, I tend to talk a bit loudly sometimes in the real world without meaning to and I wanted to convey that here. (I know, seems like some demented form of artistic expression, but that's the way my mind works.)

And not meaning to sound like a n00b, but what's an alpha channel? (It's something to do with transparency, right? I shoud know this...)

[t00fri]

I used a jpeg file, with average detail preservation. I also applied a slight gaussian blur before saving . Would that affect anything? I'm using adobe photoshop elements 2.0 for the editing... I know, a little archaic, but adobe photoshop 5.0 limited edition sometimes crashes when I'm in the middle of something, and anyways, I'm too lazy (and cheap) to go out and get a newer version.

Good, thanks. Now we have a rather well-defined problem...

Do your dark blockings along coastal lines look more or less like in this highly zoomed view here? Note the specular reflections in the many little lakes!! So also in this example we have a combination of specular illumination and normalmaps...

Not meaning to be sarcastic, but is this colour of text any less painful to look at? I want to use a greenish font, but don't want to upset people. The reason I use bold font is, I tend to talk a bit loudly sometimes in the real world without meaning to and I wanted to convey that here. (I know, seems like some demented form of artistic expression, but that's the way my mind works.)

And not meaning to sound like a n00b, but what's an alpha channel? (It's something to do with transparency, right? I shoud know this...)

Note, I LOVE a pinch of sarcasm here and there Only Selden does not...
So never mind. This color of yours looks like an improvement to me. Yet the boldface is a strain, still.

Fridger

[Vorthon]

It's bigger and more subtle, being only slighly darker than the surrrounding ocean, but it's still an eyesore.

[Spaceman Spiff]

Eeee! I thought t00fri would be repelled by the bold green font, but I see he's taken you in his more-capable-than-mine hands! It must be because you've made it more teal...

We need a picture of your eyesore. Can you do a screenshot and upload it as an attachment?

Yes, alpha channel is usually transparency, but Celestia is using it as a specular map here. (Hmm, I thought a JPEG didn't have alpha.)

By the way, 1024?512, that's a 'low' resolution. Do you know about replacing textures, so you can use a higher resolution one?

And we still don't know much about your computer specs, especially the graphics card.

Spiff.

[Vorthon]

I can't post a screenshot because I'm in the middle of revamping the textures, and I saved over the original file before I finished the new file, so it will look grey puke or something if I do take a screenshot.


as for the specs...

Intel Pentium M
Proccessor: 1.86GHz
335 MHz, 512 MB of RAM

[t00fri]

Eeee! I thought t00fri would be repelled by the bold green font, but I see he's taken you in his more-capable-than-mine hands! It must be because you've made it more teal...

Well guessed . Teal fits much better to my colors. So that's progress. Boldface still makes me nervous

We need a picture of your eyesore. Can you do a screenshot and upload it as an attachment?

Right...

Yes, alpha channel is usually transparency, but Celestia is using it as a specular map here. (Hmm, I thought a JPEG didn't have alpha.)

The typical Celestia textures are composed in the following way

rgbargbargbargba....

where each of r,g,b,a is an 8bit=1byte number (ranging thus between 0 and 255). r=red,g=green,b=blue, while a=alpha. 0 means black and 255 is white. For the 4th, so-called alpha channel, white means totally reflective while 0 is NO reflection at all . Hence in Celestia we use so-called specular masks that either are black (no reflection over the land) or white (over oceans, rivers, lakes), since water reflects the sun very much...
Here is a coastal patch, for example, from our CelestialMatters site where we discuss texture issues at an advanced level...:

(the following example is from cartrite, modulo inversion )


With BOTH the base texture and the specular mask, this then looks like so:

(click for BIG!)

delawarenewjerseynewrj4.jpg

In Celestia you may either have a separate specular mask defined in your .ssc file or you place the mask on top of the rgb base texture (as 4th "color" so to speak). This latter option is more economic as to storage etc...

So far for some general background...

Fridger

[Vorthon]

Oh... so I guess I sholud get rid of any grey in the spec map...

[t00fri]

Oh... so I guess I sholud get rid of any grey in the spec map...

Didn't you read what I wrote here, precisely concerning the issue of a little residual "rest light" over land areas (for which mostly one tends to use a black specular map)!? "Rest light" means to use a very dark gray instead of black.

viewtopic.php?f=5&t=2019&start=28

If you are really interested in acquiring advanced know-how of texture making, then I highly recommend our CelestialMatters site,

Forum:
http://forum.celestialmatters.org/
Website:
http://www.celestialmatters.org/

and there notably the forum about my F-TexTools and the corresponding normalmap tools (nmtools). If you want to learn some secrets about normalmaps, my tutorial should be illuminating:

http://www.celestialmatters.org/?q=node/10

Some recent high-quality textures for the Celestia 1.6.x and Celestia.Sci you finde here:

New Titan 2009:
http://forum.celestialmatters.org/viewtopic.php?t=305

Iapetus (4k) and Enceladus (16k, 4k) & 23k Dione:
http://forum.celestialmatters.org/viewtopic.php?t=300
http://forum.celestialmatters.org/viewtopic.php?t=100
http://forum.celestialmatters.org/viewtopic.php?t=224

Phobos in TrueColor:
http://forum.celestialmatters.org/viewtopic.php?t=225

You also find the best models for various spacecraft over at CelestialMatters.

Fridger

[Vorthon]

Woops... I wasn't exactly awake when I read that post... kinda the result of waking up in the middle of of the REM stage of the sleep cycle. I'll take your advice and head over to CelestiaMatters.