[Bf-committers] image-save + .blend save destroys work without warning!

[Morten Mikkelsen]

I've found that most blender users incl. advanced ones generally don't know
this about blender
so I think it needs to be discussed. Let me first explain how this works.

What happens is that when you save out an image to file and then
subsequently save
your .blend and then reload your .blend then the image buffer will be
reloaded from
the image you saved.

As an example let's say you went through the hard work of hand painting a
floating point image
and then save out, in Blender, as png, tga or even tiff (which is setup to 8
bits). If you then save the .blend file (and reload)
then all your precision is lost and cannot be recovered. No warning is given
and no options are presented
when saving out an image.

A similar example is alpha. Most of the image formats support alpha but for
whatever reason Blender
does not save alpha with all of them. If you pick such a format, save, then
save the .blend
and finally reload .blend then the alpha will be lost.

I was hoping to have a discussion here on committers and hear what you all
think is a good solution.

I can personally understand why blender chooses to reload images from file
since saving the image buffers with .blend file directly (to preserve them)
is just asking for an explosion
in file size. But in my opinion there should be a warning when there will be
loss of data associated with a save (when its not just straight
pass-through).
Also I would prefer that when you do save out that you should be presented
with options available for the chosen file format
such as bit depths and number of channels or something.


Cheers,

Morten Mikkelsen