Today i found a link to a polish forum on my blog.
The problem was about a user trying to make a diagonal grid and one of my blog entries was given as the solution.
You use the Grid filter on a bigger transparent layer, then rotate to get diagonal stripes.
So in my example the canvas is 800x400px, but the grid layer is 1200x1200px.
Next, user was working with a layermask to non destructively "erase" some areas but whenever the layer is moved, the mask moves with it.
This is actually one of the features i'd like to see in Gimp. In PS you have a chain between mask and layer and unlinking it, lets you move them seperately.
One user gave the solution of using the Offset Dialogue (CTRL + Shift + O), which works on layer and layermask.
When i try to use the Float trick, only the visible pixels get selected.
So why can Offset move pixels outside the canvas area, but Select All cant ?
1) You can't, because by definition, being a mask it has the same boundaries as its layer. However, you can shift the contents within the boundaries, Layer>Transform>Offset also works on the layer mask.
2) Copy, yes, select no (in other words, they have to be selected by default). Try this:
create a 200x200 image,
add a 400x200 layer, make sure there is no selection, then fill that layer with something. By moving it around in the canvas window, you can check that it is totally filled, so the fill happened outside the canvas boundaries (which is already one case where Select-All and Select-None aren't equivalent)
With the path tool, create a closed path outside the canvas but within the layer boundaries
Select>From path. No marching ants. Notice that Select>None is grayed out, so there is no selection
Edit>Copy
Edit>Paste as>New image. The new image is 400x200, so the whole layer was copied.
01-21-2018, 10:58 PM (This post was last modified: 01-21-2018, 11:02 PM by Espermaschine.)
on 1)
Well what you can do is activate the 'Show Layermask' option and move it around.
But this can not be reversed, as the layerboundaries "eat away" whats outside.
So it seems the only way you can work non-destructively is making the mask on another layer and copying it, or applying the mask from an alpha selection.
on 2)
is that the explanation why Offset works on a layer ?
(01-21-2018, 10:58 PM)Espermaschine Wrote: on 1)
Well what you can do is activate the 'Show Layermask' option and move it around.
But this can not be reversed, as the layerboundaries "eat away" whats outside.
Yes, it's clipped tot the layer contents. It works like Layer>Transform>Offset without the "wrap" option.
(01-21-2018, 10:58 PM)Espermaschine Wrote: So it seems the only way you can work non-destructively is making the mask on another layer and copying it, or applying the mask from an alpha selection.
(01-21-2018, 10:58 PM)Espermaschine Wrote: on 2)
is that the explanation why Offset works on a layer ?
No this is an answer to the Select-outside-canvas question
(01-22-2018, 12:23 AM)Ofnuts Wrote: it's clipped to the layer contents.
when you say clipped, that sounds like it theoretically could be released....?
(maybe not with the means we have as users, but on a code level by the developers ?)
If you want a "drawable" that can have any size and position, this is no longer a mask, and the whole thing is closer to some kind of "Set-Alpha" layer blend mode.
(01-22-2018, 06:46 AM)Ofnuts Wrote: If you want a "drawable" that can have any size and position, this is no longer a mask, and the whole thing is closer to some kind of "Set-Alpha" layer blend mode.
I see. Why is it that PS has clipping masks, but Gimp doesnt ? A clipping mask is vector technology, right ?
I dont understand why Gimp has this very limited vector capability. We do have paths, but we dont have filled paths, which would be much better for basic shape building.
Arent fonts some kind of vector tech too ?
From what I see of clipping mask(*) they are just bitmaps, and as far as I can tell, they are just working like a blend mode, by applying the mask's opacity to the layer above it. Nothing earth shattering...
Gimp isn't inkscape (and Photoshop isn't Illustrator either). As far as I know the paths in Gimp are mostly meant to create selections (filling a selection is just one use).
