[Gimp-user] Help with Gimp Transparency/Alpha Channel
Hi, I'm trying to figure out what the problem is but you mention too many things so I'm afraid I'm getting confused. Could you please give a step by step example of what you are doing and what happens when you are doing it, so I or someone else here can help find out what is going wrong? Thanks, Jolie I am using Gimp 2.67 I am modifying textures for a video game. The video game applies a special effect to the areas of the texture that are not 100% transparent or 100% opaque. I am trying to make certain parts of the texture 100% transparent so that it is invisible in-game and not subject to the special effect. I have used the eraser, rectangular select, and free select tools, and they all have the same problems. Basically, what happens is that the area outside of my selections or erasing also seems to be affected. I have antialiasing off for the free select tool. I have hard-edge on for the eraser, and all the brush dynamics turned off for it. The eraser is at Circle (05) which is a square, at the scale of 1.00 I have tried using SelectSharpen The rectangular select tool has antialiasing checked and greyed out, so that I cannot uncheck it. I believe this was introduced in one of the most recent versions (I recently upgraded' to gimp 2.67) as I don't remember seeing that in a version I used to use, I think it was 2.1 or 2.2. I also don't remember having this problem with those versions. The areas outside of my selections and erasing are being affected, so that in-game the special effects are applied to areas I don't want them to be. I have looked in the alpha channel, and there appears to be no actual transparency in those areas, it seems to be solid black. Is there anyway to ensure that the areas outside of my selections will not be affected? Also, I would like to know how to copy the exact alpha channel from one image to another image, without the original alpha channel being changed. I have tried doing this before but the alpha channel always looks different when pasted into the second image. Thanks! -- jolie S (via www.gimpusers.com) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Help with Gimp Transparency/Alpha Channel
On Thu, 2009-08-27 at 17:16 +0200, jolie S wrote: I'm trying to figure out what the problem is but you mention too many things so I'm afraid I'm getting confused. I didn't see the original question, but let me see if I can help that user. Basically, what happens is that the area outside of my selections or erasing also seems to be affected. I have antialiasing off for the free select tool. I have hard-edge on for the eraser, and all the brush dynamics turned off for it. The eraser is at Circle (05) which is a square, at the scale of 1.00 I have tried using SelectSharpen I assume you're trying to apply transparency directly to the layer content. Don't do that. Make your texture in an image layer and then apply transparency through the use of a layer mask. White areas in the mask will have no transparency when you save the file. The areas outside of my selections and erasing are being affected, so that in-game the special effects are applied to areas I don't want them to be. Does the game operate on alpha channels values 0 or does it operate if sees *any* alpha channel? If the latter, then you have to make separate textures for the areas that will and won't be affected by game play. If the former then the layer masks should work for you. I have looked in the alpha channel, and there appears to be no actual transparency in those areas, it seems to be solid black. You know, after all these years I can't remember if 0 is transparent or 255 is transparent in the alpha channel. I thought 255 was fully opaque. But my brain is full. I think that bit of info slipped out on the last refill of the tank. Also, I would like to know how to copy the exact alpha channel from one image to another image, without the original alpha channel being changed. If you use a layer mask you can make a selection of the mask, add a new mask to the other image and then copy in the old mask over the new mask. -- Michael J. HammelPrincipal Software Engineer mjham...@graphics-muse.org http://graphics-muse.org -- Take into account that great love and great achievements involve great risk. - Credited to the Dalai Lama. ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Discussion on available GIMP books (was Re: how to use layers)
On Wed, 2009-08-26 at 14:48 -0700, Patrick Horgan wrote: o Michael J. Hammel's book, The Artist's Guide to GIMP effects 2009, is a brilliant book as well. He also posts to this list and is a wonderful guy. Buy his book too! Well, wonderful might be a bit strong. :-) o Michael Hammel's, Essential GIMP for Web Professionals. His Artist's guide from 1999 was recently updated Sort of - the Artist's Guide to GIMP Effects is the 2nd in that series. The original was never updated. I decided there were plenty of reference guides and the world didn't need another one. The new book is more tutorial oriented. and is one of my favorite two books on GIMP. It covers a lot about using GIMP for the web so I don't know if he has any plans to update this book. That book didn't sell very well. In fact, it never made enough to pay me more than the relatively small advance I got for it. So there wasn't much of a market for it to be updated. Prentice Hall has not asked for an update, at least. Personally, I don't think graphics texts for tools like GIMP do well unless printed on glossy paper so the images have a bigger impact on the audience. Akkana's and Cary's texts are the exception, it would seem. :-) I've been trying to update the GIMP Effects book for 2.6 (it's for 2.4 or maybe 2.2 - I can't remember now) but it's just hard to find the time. It shouldn't matter that much, however. I wrote the GIMP Effects book on the idea that the location of menu items doesn't matter so much as knowing what those features *DO* and I focused on core features: Levels, Curves, Layers, etc. I purposely tried to avoid filters that might change with the next release since many filters are just convenience options for using one or more of the core features. The idea is to teach a little about what you're doing to the pixels. Where the tools are in menus won't matter if you don't know what to do with them. So the update would just be to point to the new locations of menus, etc. Unfortunately there is a lot of stuff that is reference material in there that needs to be updated too. If you're interested, I write a monthly GIMP column in Linux Format magazine. You can see some of the final images for those tutorials in my LXF gallery (http://www.graphics-muse.org/wp/?page_id=126). The magazine is printed in the UK so US readers will be about a month behind on the newsstand. I can't post the tutorials on my web site (except for some very old and outdated ones), however, since LXF owns the rights to them. Anyway, thanks for the kind words. -- Michael J. HammelPrincipal Software Engineer mjham...@graphics-muse.org http://graphics-muse.org -- Take into account that great love and great achievements involve great risk. - Credited to the Dalai Lama. ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
[Gimp-user] Measure tool (feature proposition)
Installation depends on your OS, but you do need python installed. If your OS is Windows and you do not already have python installed, I think that you need to install python, then re-run the GIMP installer - but Windows is not my primary OS, so that could be wrong. Once python is available in GIMP (Filters-Python-Fu-Console), place the plug-in into the .gimp-2.6.x dir in your docs folder. In linux, you just need to install python-gimp (or gimp-python, don't remember) and place the plug-in in ~/.gimp-2.6 and make sure it's executable. I found that, also, if you put the python script in your plug-ins folder it also works. ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
[Gimp-user] Help with Gimp Transparency/Alpha Channel
Hi, I'm trying to figure out what the problem is but you mention too many things so I'm afraid I'm getting confused. Could you please give a step by step example of what you are doing and what happens when you are doing it, so I or someone else here can help find out what is going wrong? Thanks, Jolie Sorry about that. I figured that I wasn't explaining it very well, but I wasn't sure how to rephrase it better. Michael was right that I was trying to apply transparency on the layer directly, by using the delete button on selected areas. I assume you're trying to apply transparency directly to the layer content. Don't do that. Make your texture in an image layer and then apply transparency through the use of a layer mask. White areas in the mask will have no transparency when you save the file. Thanks that really helps. Does the game operate on alpha channels values 0 or does it operate if sees *any* alpha channel? If it's anything more than 0 but less than 255, it applies the special effect. If it is completely black 0,0,0, it becomes invisible/completely transparent. If it's completely white 255,255,255 than it's opaque and no special effects are applied. If you use a layer mask you can make a selection of the mask, add a new mask to the other image and then copy in the old mask over the new mask. Thank you Michael, your tips are very useful. That makes editing alpha channels a lot easier. I can still see the special effects where they aren't supposed to be, but that's only if I change the settings so that the model (that uses the texture) is scaled to become larger. So that special effect is still there, but fainter. Maybe there's something I'm not doing to remove this completely, but you've been a great help. -- frustrated1 (via www.gimpusers.com) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
[Gimp-user] Help with Gimp Transparency/Alpha Channel
I'm not sure, but it seems like rather than the areas outside of selection being affected, not all of the selected area is becoming transparent. I used the paint bucket (which is set to 100% opacity) to fill the selection in the layer mask (which is acting as the alpha channel) with white. However, the left-most column of the square selection was not completely transparent in-game. It might just be something wrong with the game, because I looked at the color values of the area I wanted to make completely transparent and they are all 0,0,0. Thanks again for the alpha channel tips, I really appreciate it. Also, I'm using .tga files. Maybe RLE compression has something to do with this, but I always have it unchecked. -- frustrated1 (via www.gimpusers.com) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Help with Gimp Transparency/Alpha Channel
On Thu, 2009-08-27 at 23:54 +0200, frustrated1 wrote: I used the paint bucket (which is set to 100% opacity) to fill the selection in the layer mask (which is acting as the alpha channel) with white. Create a white layer mask initially. Make your selection in the image window (make sure the layer mask is active in the Layers dialog by clicking on the mask thumbnail). Reset the FG/BG colors by typing D in the image window (resets to default colors). Then drag the foreground color (black) into the selection. That adds black to the selected area in the layer mask. The black area is the area that will be transparent in your saved image. If the selection is not feathered then the edge of the selection should (I believe) not be anti-aliased and should either be completely transparent or completely opaque. However, the left-most column of the square selection was not completely transparent in-game. It might just be something wrong with the game, because I looked at the color values of the area I wanted to make completely transparent and they are all 0,0,0. Might be a bug in the game. Expand your selection by 1 pixel and do it again. Also, I'm using .tga files. Maybe RLE compression has something to do with this, but I always have it unchecked. No idea. It's possible, but that would probably be a game issue, not a GIMP issue. -- Michael J. HammelPrincipal Software Engineer mjham...@graphics-muse.org http://graphics-muse.org -- Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty or safety. Nor, are they likely to end up with either.-- Benjamin Franklin ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
[Gimp-user] Modifying an image...
I am very new to The Gimp and, at the moment, floundering :-( I want to have some CDs printed with the LinuxMINT logo but the person printing the CDs for me wants the image modified to remove the 'hole' in the centre. I've copied part of the image in an ellipse to cover the 'hole' but am left with the edge of the circle, and have no idea how to blend this with the rest of the image. Any tips would be very welcome but not too technical, please. Zed -- zed ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Help with Gimp Transparency/Alpha Channel
Just out of curiosity, do you know if the game engine you're using is expecting a premultiplied or non-premultiplied alpha channel? My assumption would be the former, but I figured I'd ask to be sure. Jason frustrated1 for...@gimpusers.com wrote: I'm not sure, but it seems like rather than the areas outside of selection being affected, not all of the selected area is becoming transparent. I used the paint bucket (which is set to 100% opacity) to fill the selection in the layer mask (which is acting as the alpha channel) with white. However, the left-most column of the square selection was not completely transparent in-game. It might just be something wrong with the game, because I looked at the color values of the area I wanted to make completely transparent and they are all 0,0,0. Thanks again for the alpha channel tips, I really appreciate it. Also, I'm using .tga files. Maybe RLE compression has something to do with this, but I always have it unchecked. ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
