Stephen J Baker wrote:
I would rather hide that widget from Joe Public to avoid confusing him
than to unnecessarily destroy valuable data.
Let me say this one more time: If GIMP produces truly undefined data
where Alpha is zero - then GIMP will become utterly useless for
painting texture maps for 3D graphic applications. That's DEVASTATING
to a large number of your users.
Let me be clear, and hopefully just one more time. As far as I'm
concerned, we're never going particularly out of our way to willfully
smash/destroy/eat/zero data belonging to a value that has that become
undefined -- but for any number of reasons (mostly optimizations
of some sort) it happens, and will increasingly happen in the future
of GIMP as a pixel's VALUE becomes further abstracted from its
REPRESENTATION (example: is your favourite 10,0,80 HSV pixel being
passed between GEGL stages as HSV, XYZ, L*a*b* or RGB? That will
depend, and you will never know).
The question is, should we expose non-power-user tools (one tool in
particular, in my mind) that give the illusion that a pixel's raw
byte representation is precious to the GIMP core? If your alpha
channel is really a mask, use a mask. If your alpha channel is
really an aux channel (i.e. specular index map), use an aux channel.
If you are a power-user and willing to take your chances with alpha
and particular power-user tools, know the risk and take your chances.
If your favourite file-format plugin does not export and import
alpha channels that are spec'd to contain non-destructive
transparency data as layer masks, take it up with the author of
your favourite file-format plugin.
GIMP will always be (utterly) useful for painting texture maps
for 3D graphics applications, but if you want and need a TRULY
orthogonal (in the colourspace sense) channel in which to put
your decal mask (or other attributes) then put it in one of the
various supported GIMP data channels which are better suited to
this purpose, if you wish your process to be futureproof.
--Adam
--
Adam D. Moss . ,,^^ adam@xxxxxxxx http://www.foxbox.org/ co:3
Consume Less, Live More
