Re: [Gimp-developer] Transformation obeying layer blending?

[Øyvind Kolås <pippin gimp org>]

On Thu, Mar 2, 2017 at 12:06 PM, Tobiasz Karoń <unfa00 gmail com> wrote:
> When doing transformations (scale, rotation, perspective transform) the
> transformed layer "pops out" and transformed part of the image is fully
> opaque and drawn on top of everything else together with the transfomation
> gizmo/controls/grid.
>
> Sometimes I'd like to be able to make this semi-transparent to be able to
> align one layer to another, laying underneath it.

The current live preview uses cairo to render the transformed layer on
top of the UI, as mentioned - in 2.9 / 2.10 with the ability to
control the opacity of the previewed transformed layer. This is
awkward, but at last in many cases is a better realtime indication for
adjustment than only having a grid, which is all GIMP had bedfore this
proxy preview was added.

Work recently/currently being done in GEGL enavling mipmap preview
rendering, permits future versions of GIMP to do interactive preview
in its correct position in the layer stack and at configured opacity
and blending mode. This is not a blocker for 2.10 though - it is an
improvement that likely will get attention in the 3.x cycle, possibly
while also gaining the ability to do non-destructive transforms as
filters attached to invididual layers/groups.

/pippin - GEGL maintainer - http://patreon.com/pippin