Re: [Gimp-user] Need help with lighting effect

[Steve Kinney <admin pilobilus net>]

On 01/01/2017 03:54 AM, rich2005 wrote:
> > Thank you!  That helps a lot!
> >
> > I have another question if you can/want to answer it: is there a way
> > to see the image under the black mask layer?  I keep having to go to
> > Layer > Mask > Show Layer Mask and selecting/de-selecting it to check
> > my progress.
>
> Not sure about what you need.
>
> If you need to see the bottom layer as original, then turn off the top layer
> visibility - the 'eye' icon on the left side in the layer dialog.

If you hold down the Control key and left click on the layer mask in the
Layers dialog, the mask it "toggled off" and the whole layer becomes
visible.  Repeat to turn the mask back on.

If you hold down the Alt key and left click on the layer mask in the
Layers dialog, the mask becomes visible on the canvas "as if" it was a
normal layer by itself.  Repeat to toggle visibility off.

In some cases it may be useful to leave masked areas partially visible
by using gray instead of black on the mask, i.e. when painting details
"back into the picture" with white on the mask, then use the Color
Curves tool to make the gray into black when finished.

The Quick Mask tool can serve a similar purpose; with the tool turned
on, "paint" on the canvas with black or white to create your intended
mask.  Toggle the Quick Mask tool off and the regions you painted become
a selection; add a layer mask to the layer you are working on, drag and
drop black onto the canvas to make a "real" mask from the quick mask.

:o)