Thread: Setting Gimp on the throne

Originally Posted by icosahedron

Is is possible accurately to re-select something once you've let go of it? How?

Yes. Use the Select > Save to Channel. This saves the selection as an "alpha mask" in the channels dialog. If you don't have that showing, you can with Windows > Dockable Dialogs >Channels (but I think it is in the default dock. It is the tab that looks like this:


The arrow points to the button that lets you load up a saved selection.

If you intend to save many selections, I would suggest renaming them (double click on the "Selection Mask copy" text and give it a new name, like "Seat Selection"

Originally Posted by icosahedron

How do I darken/lighten selections (eg to make two sides of the plinth shadowy)?

When you have a selection, thee are a number of ways to lighten and darken it. I would suggest starting with Colors > Brightness/Contrast.


No time for the others right now, sorry...

-Rob A>

Thanks for that Rob.

I have another problem with the Gimp.

I've tried to save my throne as a png with a drop shadow around it. I can save the throne with a transparent background, but as soon as I try to put a drop shadow around it and save, I get this popup:

Your image should be exported before it can be saved as PNG for the following reasons:
PNG plug in can't handle layers

* Flatten image

* Merge visible layers

If I choose to flatten, the background becomes white instead of clear, and if I choose to merge, Viewingdale's PNG to VMI converter has a "runtime error" whatever one of those is, when I try later to convert the PNG.

I don't know why I get the popup at all, because I've previously saved images with a drop shadow and it just saved ok.

Any idea what's happening?

Cheers.

Can you post me any file that consistently causes a runtime error. I was aware a long time ago that 16bit PNG's caused it to go bad but that was supposed to be fixed ages ago where it stripped off the bottom byte and made it 8bit instead. No image should cause it to crash. Anything that causes any of my apps to crash I wanna know about pronto !

If you can mail something can you just check the version number of the converter app and see if its V1.06 ? Maybe I screwed up the patcher and its not dishing out the latest one.

PNG is a file format with a number of styles but the main one is a colour set of red green and blue and the transparency amount called the Alpha so its known as RGBA. These come in 8 bits per pixel or very rarely 16 bits per pixel. But thats it. There are no layers saved with PNGs. If you merge the layers in Gimp and save out then it loses the layers in the file.

I wouldn't have expected Gimp to merge and save the file as a 16bit PNG but you never know...

Edit -- Tried many options all similar to that described and I cant get a crash. Could do with that specific file there.

Originally Posted by icosahedron

Thanks for that Rob.

I have another problem with the Gimp.

I've tried to save my throne as a png with a drop shadow around it. I can save the throne with a transparent background, but as soon as I try to put a drop shadow around it and save, I get this popup:



If I choose to flatten, the background becomes white instead of clear, and if I choose to merge, Viewingdale's PNG to VMI converter has a "runtime error" whatever one of those is, when I try later to convert the PNG.

I don't know why I get the popup at all, because I've previously saved images with a drop shadow and it just saved ok.

Any idea what's happening?

Cheers.

Make sure you have a layer selected and NOT one of your channels. I accidentally do this once in while and you just have to go back to the Layers tab and select a layer. NOW... first... don't save it as a png cause then you can't easily edit the layers which eliminates the entire power of GIMP. Save the file before ANY CHANGES as a native gimp file (.xcf). Then as you make changes with new layers (if needed, depending on what you are trying to do), you using the Save a Copy menu setting to "transform" a copy of the native gimp file to another format such as png or jpeg.

If you still have problems, if you would save it as a xcf file, zip, and attach to your post I can take a look at it based on your steps.

I doodled this up in Inkscape -

It might have a better shape on the chair back for your needs.



-Rob A>

Thanks for the support guys, all useful info there. Bit of a bind that I need to store two copies of the drawings, one for Gimp and one for all other apps, especially as I'm just starting to realise how much space graphics storage can eat, but I can see the value of it.
I suppose I could just store in xcf and print pngs on demand...

I eventually managed to get the file to a suitable PNG by just poking about with it. Still not sure what I was doing, but it worked. Wish I'd got your replies about saving in native format before I closed down for the night, JF, but hey, it's just an experiment. Once I get used to the software, I could probably reproduce in a few minutes what it's just taken me several hours to create by trial and error. And I know for next time.

Redrobes, it wasn't what I'd call a crash, nothing locked up or trashed my work, it was more of a refusal to comply with a request. I'll PM you, but I think I've overwritten that file.

Right now, I don't even know the difference between a channel and a layer. I'll get there eventually. Surprisingly, Gimp hasn't scared me off yet, in fact I might be able to do most of the simple stuff I always wanted to do without too much learning. After that, it's all bonus.

I'll be happier when I get a windows copy of the help file. I'll email Gimp today and see where they've hidden it. It's a PITA to have to look things up online, on another computer, that might not even be powered up at the time.

Here's the current version, background is now properly transparent and I've cleaned up some of the ugly black lines with a bit of pixel-clicking. I might try rounding off a few corners next, though that's gonna make area selection almost impossible.

That seat-back looks great, Rob. See, no matter how good the software is, it's no substitute for talent - unfortunately for me.
Hmm. It shows up the fact that my seat back is too wide, it shouldn't overhang the plinth. Can't fix that without starting again from scratch, though.

Looks a bit tombstoneish at pres...

C&C anyone??

Originally Posted by icosahedron

Right now, I don't even know the difference between a channel and a layer. I'll get there eventually. Surprisingly, Gimp hasn't scared me off yet, in fact I might be able to do most of the simple stuff I always wanted to do without too much learning. After that, it's all bonus.

Lets do the simple one first. A channel is a special layer that is b/w only. Typically, it's used to make masks(come back to this one later by viewing my tutorial in my sig on layer masks.)

A layer is just what it sounds like. You draw stuff and as you draw stuff on higher layers, they overlap. This is exactly the type of thing used in animation (except images are not animated of course). So.. in your example below, I would probably break your chair up into component parts. The base would be the lowest layer, followed by the seat, then the arms and finally, the back as the highest layer. Generally, you would put drop-shadows on the lowest available layer of an image after you have created the whole thing. If you have ever seen any type of animation cells the old way, they will have several layers of clear plastic type stuff and draw different things on each of those plasticy layers and then put them together into a single "frame" to form one cell of an image. Layers in GIMP are pretty much the same.

Originally Posted by icosahedron

I'll be happier when I get a windows copy of the help file. I'll email Gimp today and see where they've hidden it. It's a PITA to have to look things up online, on another computer, that might not even be powered up at the time.

Do you have the latest version or an older version of GIMP?

http://gimp-win.sourceforge.net/old.html There is a link to several language specific helpfiles for an older "dot" release(only a few months old and no feature changes, just bug fixes, so should be up to to date)

Originally Posted by icosahedron

Here's the current version, background is now properly transparent and I've cleaned up some of the ugly black lines with a bit of pixel-clicking.
C&C anyone??

Overall, I think you did a really good job!

I might try rounding off a few corners next, though that's gonna make area selection almost impossible.

This is where building in layers makes a WORLD of difference in ease of editing later...

Nice Work!

I picked up a few tips at the Dundjinni user art forum while making this type of object.

Here is a rework of your throne:


The only difference is in the shadows. I reduced the overall outer shadow.

Keep it a bit closer to the object then you had. I lightened it at the back of the throne, cause higher objects tend to cast a less distinct shadow.

I added shadows across the seat font and arms to give more illusion of height above the base.

I shaded the left and right of the base slightly to define the corners to the front.

All of this was done with new layers (the extra shadows/shading) or layer masks (reducing the existing shadows) to make it effectively "non-destructive" on the original image.

And layers is what lets you do (more non-destructive) things like adding a solid dark violet layer in "grain extract" mode to get a variant like this:



and my changing that colour layer you can create a whole plethora of different coloured thrones as needed.

Keep working at it! See, Gimp isn't that hard!

-Rob A>

Originally Posted by icosahedron

Redrobes, it wasn't what I'd call a crash, nothing locked up or trashed my work, it was more of a refusal to comply with a request. I'll PM you, but I think I've overwritten that file.

That was a crash. If you had been running a program like Gimp or Photoshop and had many hours of work painted and it did that then you would lose it unless it had some kind of autosave facility. Crashing apps are a pain. I got your image now so ill look into whats going on. I have used the converter extensively and have not seen it before so glad it happened at a non critical moment.