Celestia Forums

Hi all,

Just thought I'd point potential texture creators to another tool for
use in the creation of textures for planets, asteroids, etc...

See: http://photofiltre.en.softonic.com/ for the download of
PhotoFiltre.

The main reason I offer this link is because it offers a VERY easy way
to view and modify those nasty seams which can occur if every side
of a texture is not perfectly aligned with the next. In other words, if
your texture's right edge doesn't match its left edge, then you get
some really undesirable effects where you don't want them.

Using PhotoFiltre, you can very easily adjust an image's offsets so
that you can SEE any seams immediately. Simply load your texture,
then apply IMAGE and OFFSET - say to 400 pixels - and you'll
see the texture's true image as it will appear when the edges
are joined together.

Just FYI...

Thanks, Brain-Dead

Bob,

this is a standard feature in THE GIMP image manipulation package, which exists for all platforms. But of course, some people might prefer some special software for that little task.

Bye Fridger

Sorry Good Doctor, but I didn't even discover the offset routines in
the Gimp until I had played with it for about a year. This program is
enormously easier to use, so I just offered the reference for
others.

Thanks, Bob

BobHegwood wrote:Sorry Good Doctor, but I didn't even discover the offset routines in
the Gimp until I had played with it for about a year. This program is
enormously easier to use, so I just offered the reference for
others.

Thanks, Bob

So let me tell you, where you find it. It's really EASY

On the image you are working with, click the RIGHT mouse button, whence you'll see a popup menue at the mouse position. While pressing the right button, move with the mouse cursor to


Layer -> Transform -> Offset (at the bottom)

and then release the right mouse button.

A new dialog appears (Offset Layer)

Enter the number of x-offset pixels into X:
Typicallly, if the width is w pixels, you would enter w/2 into the X: window.

Make sure that "Wrap around" is activated and hit OK.

That's all. Complicated?

That's also PRECISELY what you have to do with any textures in simple cylindical projection format, using a different central meridian convention than Celestia! E.g. all textures by Steve Albers.


And of course, I never use click menus, but rather
hit

SHIFT+CTRL+O

and I am right there in the offset dialog.

At the end of your seam inspection, you do the same operation once more and your texture is back in the original state. Of course you can also do offsets in height (Y) with this dialog or in both, width (X) and height(Y).

The very reason why I am against using "outsider" software is that one never knows what they really do with your high quality image! If their main arguments are based on "simplicity of use" they obviously cater to image manipulation novices who will hardly be able to distinguish good pixel operations from not so good ones...

Cheers,
Fridger

t00fri wrote:
So let me tell you, where you find it. It's really EASY

On the image you are working with, click the RIGHT mouse button, whence you'll see a popup menue at the mouse position. While pressing the right button, move with the mouse cursor to
Layer -> Transform -> Offset (at the bottom)
and then release the right mouse button.

A new dialog appears (Offset Layer)

As I mentioned in my post, I DO know how to use the offset in
the Gimp now...

t00fri wrote: The very reason why I am against using "outsider" software is that one never knows what they really do with your high quality image! If their main arguments are based on "simplicity of use" they obviously cater to image manipulation novices who will hardly be able to distinguish good pixel operations from not so good ones...

Cheers,
Fridger

Well, as you should KNOW by now, I too am interested in both
QUALITY and REALISM...

Why does a program have to be bad for Celestia simply because
it's EASY to use? Conversely, why does a program have to be
good for Celestia because it's complicated? Sorry, but I just do
not understand your objection here. Try the program for yourself.
It is also free, and works VERY well in modifying textures for
Celestia.

Thanks, Bob

BobHegwood wrote:...
Why does a program have to be bad for Celestia simply because it's EASY to use? Conversely, why does a program have to be good for Celestia because it's complicated?

Bob,

neither was implicit in my post.

Professional-level graphics programs like Photoshop or The Gimp can never be as simple as very specialized ones, addressing mainly novices. But they usually can perform more tasks with higher quality...

Personally, I work on Windows AND Linux in parallel, others work on MAC OS. So what we need for a cross-platform application like Celestia are cross-platform image manipulation tools!
I would get crazy if I had to switch to some other software after turning around from my Windows machine to my Linux desktop! Similarly, to explain some graphical action to some users, one must do it separately for each OS if platform specific tools are used.! Not what most of us find practical...

I bet PhotoFiltre only exists for Windows!?

Just take a simple rescaling task of an image. Let me ask whether PhotoFiltre tells you the mathematical algotithm that it uses for rescaling? Probably NOT, since most of it's users don't care, because they wouldn't know anyway what a particular name really meant for the image result.

BUT these names in practice make all the difference! Rescaling algorithms vary greatly in their results (and speed) and people who want highest texture quality for Celestia MUST know what algoithms are available to choose the right one for an optimal result.

Simple programs with names like "PhotoFiltre" presumably specialize on manipulations typically required in the context of digital photos. That in turn means that most applications would be limited to a typical, fairly small window in required resolutions. That in turn suggests to only offer algorithms that are sufficient for this limited task of retouching pictures.

However, Celestia textures often concern just another dimension in resolution compared to such typical demands...So work with Celestia texture needs much more sophisticated code in order not to vast quality.

Next comes the amount of sophistication wrto to memory management! Programs specialized to photo retouching will JUST GIVE UP when large textures are to be loaded.

Try to load and manipulate 16k - 32k Celestia textures with PhotoFiltre!! What is the largest size you can load without provoking errors?

Programs like Photoshop and The GIMP have been under development for more than a decade by large dev teams.
That by itself and their VERY widespread use by a knowledgeable community of graphics people represents a considerable affirmation of what one can expect...

etc.

Last not least. The GIMP has a very logical structure in its menus and after working on several tasks with this program, few would still find it "complicated". And there is a VERY extensive help.


Bye Fridger

I simply cannot argue with you doctor...

I agree with your mathematical view of the world, but not everyone
lives there. I am - admittedly - a Brain-Dead Celestia user, but I do
personally enjoy almost EVERYTHING you create for my favorite
program.

My real problem, I guess, is that I think we would do well to include as
many non-technical people in the creation, development, and
distribution of Celestia as possible. I get the impression from you
that no one outside of theoretical physicists should dare lay a hand
on the thing. I'm not saying that this is correct, it's just that this is
the impression I get every time I try to offer a suggestion or a hint
which is directed to the non-technical of us in the world. We are the
people who generally pay for the services which people like yourself
provide. You know? <shrug>

I LOVE ya Doc, but I reserve the right to (respectfully) disagree with you.

BobHegwood wrote: I get the impression from you
that no one outside of theoretical physicists should dare lay a hand
on the thing. I'm not saying that this is correct, it's just that this is
the impression I get every time I try to offer a suggestion or a hint
which is directed to the non-technical of us in the world.

Bob,

NONE of my above reasonings had ANYTHING to do with Theoretical Physics or Mathematics! These were just things that people with knowhow in image manipulation will be aware of, and respect.

Certainly Don.Edwards who is NOT a scientist will e.g. not use a linear rescaling algorithm but an appropriate one for the resolution under consideration. I bet he knows when a cubic spline method is required...

Certainly Runar, ElChristou or Cartrite will also take care of such general considerations of image manipulation, or Chris Laurel, for example..

None of them are Theoretical Physicists or Mathematitians...

Bye Fridger

t00fri wrote:I bet PhotoFiltre only exists for Windows!?

Yep. You GOT me there... Of course, 95% of the non-scientific
users of the world depend on Windows too.

t00fri wrote:
What is the largest size you can load without provoking errors?

I can open 8k textures easily, but I really don't know if I can use
it with larger textures because I don't HAVE anything larger. Nor
have I been able to locate anything large...

One final note then I'll shut up and NEVER suggest anything to
Celestia users again... The following describes some of the
program's features.

- Show EXIF base information for the format Raw (menu File > Image properties)
- Improvement of the filter Gradient (more directions)
- Improvement of the Copyright module (vertical center display)
- New deformation Ellipse
- All transformations (rotation, distort, ...) use a bicubic interpolation
- Improvement of the Deformation brush tool (more precise)
- Deformation tools have a real time preview
- The functions Offset, Replace color, Replace color range, Indexed colors,
Stroke and fill and Custom filter have a direct preview option
- The Transparent color button is active for layers (contextuel)
- Supports DNG format
- Drawin tools can use true size cursors
- Improvement of the filter Emboss (dialog box)
- Improvement of the Clone stamp tool (clone from other image or layer)
- The texture module can load external texture files
- New Perspective correction module
- New Horizon correction module
- Improvement of the filter Radial blur
- Improvement of the filter Motion blur (dialog box)
- Improvement of the filter Radial masque (dialog box)
- New filter Circular blur
- The drawing tools can draw on transparent area of a layer
- Improvement of the Erase tool (Invert mode for Alpha channel)
- Show active layer bounds
- The functions Progressive contour and Contour 3D auto select the layer
- Possibility to add layers in RGBA mode (transparent background)
- Improvement of the image explorer (scan textures and multiline display)

EDIT: I have used it to edit Don Edwards' 16k Realistic Earth
texture too. Sorry, but I didn't have that texture earlier.

And just FYI...

The Gimp has just been updated, so get it now.

Thanks, Bob

hi bob i get where you are coming from The Gimp can be overwhelming for the novice
know i took to it like a fish in water because of my photo and darkroom ( 10+ years ) background , but my sis. she only wants to use and learn the built-in windows paint program

for me i use
The Gimp
CinePaint
CImg
vips / nip2
ImageMagick(q16) and Magick++ for vips
isis - learning how to use it

Thanks John...

I also use the Gimp if I'm trying to do something spectacular, but -
for the novice - it IS a bit overwhelming at first. My suggestion here
was put on the board simply to make new users aware of the fact
that you can use many OTHER editors too.

Shoot me...

I'm a novice and wanting to use gimp for photo editing.

It's overwhelming that's right. But very good that somebody tells how to use the offset in Gimp. For everybody who didn't knew yet and looked at this post will have a moment of joy when he or she sees that someone is explaining how it's done.
PS: You can also just search the word offset in the TheGimpHelp

(In big programs you often need walkthroughs for this sort of simple stuff.)


If you really want to try out enourmous images for testing if it provoke errors
Download and test out displaying the NASA Blue Marble Next generation 64k.
Or a photo from NASA Photo Journal (don't know the link) somewhere there is a picture with a PNG and jpg
(the jpg version is 500MB!!!!!! jpg people, jpg!!!)
The PNG is around a gigabyte or two. So it's perfect for testing the limits of TheGimp and your system

Duds,

JPEG is a lossy compression algorithm. Like DDS, it throws away resolution to make the file small. It must not be used while developing surface textures, although JPEG and DDS might be acceptable for the final distribution. High quality, non-lossy compressed PNG images can be used for the intermediate developmental images, although that format requires more disk space than JPEG. PNG is smaller than non-compressed TIFF, TGA and BMP formats.

duds26 wrote:I'm a novice and wanting to use gimp for photo editing.

It's overwhelming that's right. But very good that somebody tells how to use the offset in Gimp. For everybody who didn't knew yet and looked at this post will have a moment of joy when he or she sees that someone is explaining how it's done.
PS: You can also just search the word offset in the TheGimpHelp

(In big programs you often need walkthroughs for this sort of simple stuff.)


If you really want to try out enourmous images for testing if it provoke errors
Download and test out displaying the NASA Blue Marble Next generation 64k.
Or a photo from NASA Photo Journal (don't know the link) somewhere there is a picture with a PNG and jpg
(the jpg version is 500MB!!!!!! jpg people, jpg!!!)
The PNG is around a gigabyte or two. So it's perfect for testing the limits of TheGimp and your system

I think most people are simply reluctant to work themselves through the excellent tutorials/manual of the GIMP. Of course, a powerful software package needs a week or two of intensive "care". But that's the same with almost everything in life that is supposed to furnish a non-trivial service.

Almost ALL ads in the US focus along the same slogans:

"Buying from us, you can own the most sophisticated and complex ...telescope, car,computer,... of this whole world, yet you can be totally stupid and still master it perfectly!"

The little catch is that Americans are NOT at all stupid

Bye Fridger

PS: The GIMP has NO intrinsic memory limits at all! The practical limits come from what you configure in accordance with the resources your computer offers.

If you want to load 64k textures FAST, it's an easy calculation, how much RAM you must buy for your machine. I can easily load 64k images with the GIMP. It's only getting a little slow since the 64k don't fit entirely into my RAM. So GIMP uses some special SWAP space on the harddisk which slows all operations down substantially.

There is even a tutorial for configuring GIMP in an optimal way. But if people don't want to read this crucial info...too bad, but certainly not the fault of the GIMP. Right?

t00fri wrote:There is even a tutorial for configuring GIMP in an optimal way. But if people don't want to read this crucial info...too bad, but certainly not the fault of the GIMP. Right?

Lest we think that I was criticizing the Gimp, let me make it perfectly
clear here that I DO use the Gimp.

I LOVE the Gimp...

I love the resources which are available to users OF the Gimp. Again,
I was simply trying to offer an alternative to the average Joe...

Shoot me again.

Other two free programs for making textures:

http://thebest3d.com/dogwaffle/free/

http://www.artweaver.de/index.php?id=59,141,0,0,1,0

Fenerit wrote:Other two free programs for making textures:

http://thebest3d.com/dogwaffle/free/

http://www.artweaver.de/index.php?id=59,141,0,0,1,0

Oh my...

Yer ASKING for it now...

Trouble-Maker Bob

First:

t00fri wrote:The little catch is that Americans are NOT at all stupid

No, not all Americans, but many more of us ARE lazy. We want it all and we want it now! And...we don't want to work hard for it...

While we are on the topic of tools, I just happened on this > OptiPNG

It is a png compression tool. I believe it's platform independent too.

I tried it out on a hires Io png and it pretty much halved the size with no discernible loss.