Help With Transparent Textures

[Guest]

I'm not expecting dramatically better compression . . . I most interested in JPEG2000 because it supports an alpha channel. As far as I know, there's no other lossy compression file format that supports an alpha channel. Celestia's current Earth texture is only a PNG because it needs an alpha channel; if it was stored in a lossy format it could be much smaller. Same for the cloud textures . . .

--Chris

I think you are right, except (4:1) DXT3, of course. Believe it or not, what I found hardest to make were my (bumpmapped) cloud textures. The balance between rgb colors and alpha info is very delicate if one wants to have really "fluffy" clouds with delicate bluish coloring. The resolution, however, is quite uncritical /if/ the clouds were reduced by /cubic interpolation/ from a much larger original! I sort of like my latest 2K clouds (c.f Central America) in Bruckner's galery.

Bye Fridger

[Rassilon]

No need...grasshopper learned something today ...I have done the compose RGBA and viola...the picture you see above is the results!

Don't tell me it's no fun...After this strong feeling of pride has settled in your chest;-) it's definitely time now to bumpmap the clouds and put some specular reflections into the waters.

Just tell me when you are ready;-)

Bye Fridger

Currently I'm gonna try my hand at making a reflective PNG file...I think I may have it soon

[Axel]

Hi folks,

all right. Thanks a lot to Rassilion (again for writing down those steps in photoshop. I don't use it as well, but I really like people to get the best help on their way into Celestia.

And I don't think I'm taking a consumer point of view in doing this. (If you don't believe me just mail me - I'll explain.) I just try to help or at least provide help because I remember beeing a newbie as well. Sure thats some decades ago

Reg. the texture pack I agree with the point that it doesn't make much sense for the normal user to download 200MBs. No matter if from us or the NASA server, btw.

On the other hand, if we would like to provide the Celestia family with the best visuals possible on their hardware we ought to think about 3 or so independend Celestia textures packs (low, med+bumps, high+bumps, all incl. config file) which can be downloaded at the main site and does not have to be updated with the binaries. So you don't have to download the 11megs again all the time.
If then an update to the textures or anything else happens by anyone, it should be published as an addition or replacement wich can be easyly reproduced locally by a newbie.
Logically any new addition or enhancement should be available to the community or have completely I missunderstood something about the open source idea here?

To put it in plain letters. If there's something pretty cool you have done, first mail it to Chris. He's a magician in making it available for everyone. Don't just put some screenshots about it somewhere and tell interested people to RTFM. Sorry.

I'm sure we can find a decent solution here as much as we helped the guy with his alpha channel question. I would simply pledge to put the add. Celestia resources more on the main site, ev. into a frame.

CU,
Axel

Hi Chris,
my first mail account screwed up, I guess. I'll send you one from an operable account

[More on Tranparent Clouds]

To t00fri,
#1 I spent more than a half hour trying Pixel's little tutorial to no good end.
#2 In my copy of WinGimp there is no selection for RGBA only RGB so you see there is a problem right there. So don't say its the operator of the software. Your wern't here watching me over shoulder so theres no way can say that I was or was not following Pixel's instructions. If the RGBA option doesn't exsist in my copy of Gimp then how the heck can I follow his short little tutorial and end up with a proper outcome.
#3 Just because your into Linux/Unix core OS does not mean the rest of us want to mess with it. I have played with Linux and I personaly don't care to go digging around in my OS's core just to ajust something. I use Window XP for many reasons. Mainly next to my iMac which has poor 3D I use it for ease of use. I want to start up the computer and go to work. I never have to worry about it crashing like Win9x based windows. Don't get me wrong, Linux is a cool OS its just not for me.
#4 Free software is cool but where is the customer support. There isn't any or its barried in read me files on there site someware and takes hours to hunt down. There are tons of tutorials for photoshop and its laid out in a logical fashoin. Gimp loads up and dumps small sub windows all over my desktop. Its user interface looks like it crawled out of Windows 3.1 or OS/2. And whats with the reversing cursor. I find that anoying. I don't like that feture in MS Word either.
Alright I am going to stop griping. I am sure this is going to generate a ton of responses from the Linux crowd but oh well. I will be working with Rassilon's instructions and see how that turns out. For me Gimp is off my system for now.

[More on Tranparent Clouds]

To t00fri,
#1 I spent more than a half hour trying Pixel's little tutorial to no good end.
#2 In my copy of WinGimp there is no selection for RGBA only RGB so you see there is a problem right there. So don't say its the operator of the software. You wern't here watching me over my shoulder so theres no way can say that I was or was not following Pixel's instructions. If the RGBA option doesn't exsist in my copy of Gimp then how the heck can I follow his short little tutorial and end up with a proper outcome.
#3 Just because your into Linux/Unix core OS does not mean the rest of us want to mess with it. I have played with Linux and I personaly don't care to go digging around in my OS's core just to ajust something. I use Window XP for many reasons. Mainly next to my iMac which has poor 3D I use it for ease of use. I want to start up the computer and go to work. I never have to worry about it crashing like Win9x based windows. Don't get me wrong, Linux is a cool OS its just not for me.
#4 Free software is cool but where is the customer support. There isn't any or its barried in read me files on there site someware and takes hours to hunt down. There are tons of tutorials for photoshop and its laid out in a logical fashoin. Gimp loads up and dumps small sub windows all over my desktop. Its user interface looks like it crawled out of Windows 3.1 or OS/2. And whats with the reversing cursor. I find that anoying. I don't like that feture in MS Word either.
Alright I am going to stop griping. I am sure this is going to generate a ton of responses from the Linux crowd but oh well. I will be working with Rassilon's instructions and see how that turns out. For me Gimp is off my system for now.

[Guest]

To t00fri,
#1 I spent more than a half hour trying Pixel's little tutorial to no good end.
#2 In my copy of WinGimp there is no selection for RGBA only RGB so you see there is a problem right there. So don't say its the operator of the software. You wern't here watching me over my shoulder so theres no way can say that I was or was not following Pixel's instructions. If the RGBA option doesn't exsist in my copy of Gimp then how the heck can I follow his short little tutorial and end up with a proper outcome.
#3 Just because your into Linux/Unix core OS does not mean the rest of us want to mess with it. I have played with Linux and I personaly don't care to go digging around in my OS's core just to ajust something. I use Window XP for many reasons. Mainly next to my iMac which has poor 3D I use it for ease of use. I want to start up the computer and go to work. I never have to worry about it crashing like Win9x based windows. Don't get me wrong, Linux is a cool OS its just not for me.
#4 Free software is cool but where is the customer support. There isn't any or its barried in read me files on there site someware and takes hours to hunt down. There are tons of tutorials for photoshop and its laid out in a logical fashoin. Gimp loads up and dumps small sub windows all over my desktop. Its user interface looks like it crawled out of Windows 3.1 or OS/2. And whats with the reversing cursor. I find that anoying. I don't like that feture in MS Word either.
Alright I am going to stop griping. I am sure this is going to generate a ton of responses from the Linux crowd but oh well. I will be working with Rassilon's instructions and see how that turns out. For me Gimp is off my system for now.

OK, let me try to answer your various points:

(1): I was talking about looking into one of the excellent GIMP tutorials that explain everything pedagogically step by step with pictures. The reason was that I felt your problem was not GIMP or Photoshop, but rather some missing basics that are nowhere better explained than in the well-structured manual.

(2) I /assure/ you that all reasonably up-to-date Versions of GIMP for Windows have RGBA compose/decompose under Image->Mode->Decompose/Compose.
I use it regularly also under Windows. Do you think I am dreaming? Like with any Software, /including/ Celestia, there is no way around doing regular updates.
What Version do you use?

(3) I have never suggested you should use Linux, for good reasons;-)

(4) If you can afford to buy Photoshop, then go and use it. But when I read this mail, it seems you dislike virtually any software somehow;-).
I can just again assure you that there is a great reference manual and tutorials (and hardbound Books as well) for Gimp that can easily compete with those for commercial programs. If you go to the (Win)Gimp site they cannot be missed...

And finally, just have a look a little further up on Rassilon's reports (in interaction with me).

His fun learning GIMP and making progress should be quite apparent;-).

And sure he has found RGBA, in his WinGimp version, right?

Bye Fridger

[Matt McIrvin]

I guess it's no help to non-Mac users, but on the Macintosh it's easy to make PNGs with alpha channels using Graphic Converter (see the "Alpha/Mask Channel" options under the Effect menu). That's how I do it. After adding and showing the alpha channel, you can paste things into it and save the result as a PNG.

Graphic Converter isn't free, but it is pretty cheap shareware (when unlicensed, it is full-featured but nags for a few seconds at startup). It's a marvel-- it not only converts graphic files to and from a mind-boggling variety of formats, but is also a capable low-end image editor. I wouldn't want to do all my painting in it, but I almost always use it in the final stages of image assembly.

[Guest]

Could be possible gimp is buggy with XP as I am using 98 SE right now...

I would suggest what Fridger says and read the manuals...just to give you a rundown on where the various controls are at

[Vicware]

You know, Photoshop 7 has a transparency export that allows
you to save a file as a png. I have to check it out - maybe this helps.

Vic

[Pixel]

I sort of like my latest 2K clouds (c.f Central America) in Bruckner's galery.

Personally i am more impressed by your accurate specular map there. How did you manage to remove the ugly (brown) continental contours?
And does someone has idea how to make angular diameter of the specular spot constant and independent of the altitude? Is it possible to do the magic with nv register combiners?

[Guest]

I sort of like my latest 2K clouds (c.f Central America) in Bruckner's galery.

Personally i am more impressed by your accurate specular map there. How did you manage to remove the ugly (brown) continental contours?
And does someone has idea how to make angular diameter of the specular spot constant and independent of the altitude? Is it possible to do the magic with nv register combiners?

Too bad. Are you sure you had a good look at the clouds?;-))

As to those ugly continental contours, I unfortunately do not remember anymore for sure, by which of my canonical manipulations I got rid of them.

It may even have been in the process of bumpmapping with this (originally 10K) superhires levelmap or the unsharp mask filtering.

A further possibility might have been the important fact that I always use /cubic/ interpolation for reducing the size.

Perhaps, I simply started with a different (better) raw file;-).
I used the one with the sea ice and the cyan blue shallow waters and discarded the additional tiff layer that darkened the colors. The quality of that appeared to be better to me. The ice caps may easily be copied to whatever image one prefers by means of "select by color"...

If you like, I look up my specular spot settings when I am home tonight. But on the code level I cannot answer your question (yet).

Incidentally, there is an ugly, black 1-2 px seam along the joining boundary of the 10K marsmap. Do you know a trick how to eliminate those seams quickly?

Bye Fridger

[Pixel]

About specular spot i think it is natural if it doesn't change it's angular diameter with distance. The effect will be amazing if implemented.

Too bad. Are you sure you had a good look at the clouds?;-))

Your clouds are good, though not sure if they are naturally looking. From plane i am sure they are, but from space...This is the reason i don't like unsharp mask too. I also produced some flufy clouds, but the final result severe depends from color mapping (i map from <0,0,0><1,1,1> to <0.6,0.7,1.0><1,1,1>)
I think we use the same raw source and my scalling algorithm is even better ->lanczos3. You already can observe the ugly contours in your 4k shots in the same gallery. The source image was already proccessed and the places where land meets the ocean there are pixels that have mixed land/ocean collor and are difficult to remove these. They look ugly in both cases included to specular mask and excluded from it.

Incidentally, there is an ugly, black 1-2 px seam along the joining boundary of the 10K marsmap. Do you know a trick how to eliminate those seams quickly?

I know this issue. It is visible also in dxt3 compressed 8k Earth. The solution for this is to use very old version of nvdxt. I am using one from 24.05.2001. The recent one is verry buggy. They even don't check for null pointers and i can't convert 8k textures on my 256Mb setup without crash. When i move to 512Mb setup it works, but then produce this black stripe. I don't remember from where i got the old version, but i can send it by email?

[t00fri]

About specular spot i think it is natural if it doesn't change it's angular diameter with distance. The effect will be amazing if implemented.

Should not be too hard to incorporate. I'll at least have a look in the code.

Your clouds are good, though not sure if they are naturally looking. From plane i am sure they are, but from space...This is the reason i don't like unsharp mask too. I also produced some flufy clouds, but the final result severe depends from color mapping (i map from <0,0,0><1,1,1> to <0.6,0.7,1.0><1,1,1>)
I think we use the same raw source and my scalling algorithm is even better ->lanczos3. You already can observe the ugly contours in your 4k shots in the same gallery. The source image was already proccessed and the places where land meets the ocean there are pixels that have mixed land/ocean collor and are difficult to remove these. They look ugly in both cases included to specular mask and excluded from it.

Now I know exactly what you mean. I think those earlier 4k shots of mine were indeed not from the original lossless format. However, you should also remember that my shots at Bruckner's are comparatively /bad/ quality jpeg sceendumps which are known to produce "color bleeding" at high compression rates.

I know this issue. It is visible also in dxt3 compressed 8k Earth. The solution for this is to use very old version of nvdxt. I am using one from 24.05.2001. The recent one is verry buggy. They even don't check for null pointers and i can't convert 8k textures on my 256Mb setup without crash. When i move to 512Mb setup it works, but then produce this black stripe. I don't remember from where i got the old version, but i can send it by email?

That's interesting! I would love to compile the nvdxt sources for Linux, but there are many missing system headers from Windows which I cannot substitute at present. Someone with a Windows compiler and the respective headers would really provide a good service to the Linuxer's here!

Of course, I would be interested to try the older version of nvdxt. You find my email e.g. in the member list.

Bye Fridger

[chris]

About specular spot i think it is natural if it doesn't change it's angular diameter with distance. The effect will be amazing if implemented.

Should not be too hard to incorporate. I'll at least have a look in the code.

This is a straightforward change to one of the vertex programs . . . It will make the vertex program slightly slower, but it will definitely make the specular highlights look much more natural. Should take me about five minutes to do this tonight . . . For anyone familiar with OpenGL, the change is effectively the same thing as enabling GL_LIGHT_MODEL_LOCAL_VIEWER.

--Chris

[chris]

I made the fix for improved specular highlights . . . I was hoping that it would just be a matter of changing the specular.vp vertex program, but I found a bug in the source that had to be fixed. So you'll have to wait until 1.2.5 I'm afraid . . . (or compile from the CVS tree)

--Chris

[Guest]

I made the fix for improved specular highlights . . . I was hoping that it would just be a matter of changing the specular.vp vertex program, but I found a bug in the source that had to be fixed. So you'll have to wait until 1.2.5 I'm afraid . . . (or compile from the CVS tree)

--Chris

I did some experiments with your modified specular spot in the CVS tree. Some aspects I still do not quite understand. Clearly, reflection from a certain material is characterized by various parameters... that determine e.g. the fraction of /diffuse/ and /normal (geometrical optics)/ reflection etc. In geometrical optics, the size of the spot is easily derived. A typical application of the latter is familiar to astro-amateurs who use the sun spot reflected in a silvered Christmas tree ball as an artifical point source...

The spot size in units of the earth radius then should approximately be proportianal to the /angular size/ of the sun (~ 0.5 degrees for the earth-sun distance). I substituted Mercury by another /identical/ earth texture and checked the size of the spot. From Mercury, the sun appears under a much bigger angle but the spot size appears ~ the same as for the true earth??
(I also chose large specular powers in solarsys.ssc to achieve a well defined spot size)

Also, when the observer is moved a /large/ distance from the earth, the brightness of the spot does not seem to decrease like 1/r^2...

I guess, I have to look more closely into the code.

Bye Fridger

[Rassilon]

A further possibility might have been the important fact that I always use /cubic/ interpolation for reducing the size.

Aye!

What I figured out to get rid of those nasty lines is using maximize in Photoshop and reducing by 1 px the actual edge of the spec map...then gauss blur by 1-2 px...Look at the picture of Traken...Here I was able to produce my own map by carefully adjusting the brightness and contrast to be at just the peak levels to change to black and white..then by blurring 1-2 px with gauss blur...I was able to rid myself of those annoying contenent contours...Its a pain but worth it...It may take several tries to get it right...be prepared

[Pixel]

I made the fix for improved specular highlights . . . I was hoping that it would just be a matter of changing the specular.vp vertex program, but I found a bug in the source that had to be fixed. So you'll have to wait until 1.2.5 I'm afraid . . . (or compile from the CVS tree)

--Chris

Good effort, but is it looking good? I mean - any comments on look and feel?
BTW, does the vertex programs work on GF2 (no dx8 capable) cards?