[Bf-committers] [Bf-blender-cvs] SVN commit: /data/svn/bf-blender  trunk/blender/source/blender/src/ drawimage.c: Images in the image editor were being draw with the wrong glBlendFunc() command
joeedh at gmail.com
Mon Feb 25 00:53:30 CET 2008
Why keep premul at all? I mean, it's not like it's needed in this day
and age. Wouldn't it be better to plan to eventually
make everything key, and have an option to convert premul images to key?
Ton Roosendaal wrote:
>> I think ton wants to make
>> everything work in key alpha anyway,
> Also that idea was rejected in the meantime... it's a nasty topic that
> needs more evaluation.
> But definitely it's like this:
> Key alpha is for:
> - painting (Image window)
> - composite operations on alpha only (like making masks)
> - while rendering a pixel (is a bit like painting...)
> Premul alpha is for:
> - subsampling
> - filtering / blurring
> - scaling
> - mipmap, etc.
> An immediate solution to solve some of the issues is to make a
> AlphaConvert Node in compositor, so you can switch types when needed.
>> so there isn't much point to my
>> bugfix in that case, especially since it's not working quite correctly
>> (texture filtering was also apparently messing up).
>> Stéphane SOPPERA wrote:
>>>> Eh it should be GL_ONE by default, after my latest commit. Hrm.
>>>> The UV
>>>> image editor image user should be per-image, but it's not, so if you
>>>> have premul on in one, it'll be on for all of them (only used for
>>>> displaying images in the uv editor, but still annoying). Maybe it
>>>> wasn't such a good idea to make this an image user flag after all :/
>>> Sorry for not replying sooner, I just tested right now.
>>> There is a behavior I don't understand:
>>> With the file compo.blend linked to the bug report:
>>> - run render
>>> - in image viewer, change image to cube_premul.exr.png
>>> -> since this image is premultiplied, it's now displayed correctly
>>> - in menu View, select Image Properties
>>> - activate premul
>>> -> as excepted (since image is already premultiplied), the edges of
>>> cube are badly drawn
>>> - select Render Result
>>> -> render result is badly drawn with dark edges (this seems to be the
>>> bug you are talking about in above message, right?)
>>> - select Viewer Node image
>>> -> this image is still drawn as usual, whereas I would have except the
>>> bug above should have premultiplied it
>>> - select again "cube_premul.exr.png"
>>> -> the premul switch is OFF and the image is drawn without dark edges
>>> I don't understand in this scenario:
>>> - Is the bad draw of Render Result the same problem you talk about in
>>> the mail above.
>>> - Why this problem does not affect "Viewer Node" image?
>>> - Why after viewing "Viewer Node" image the "Premul" button on the
>>> cube_premul.exr.png image is reset? (and why Render Result image does
>>> not have the same effect).
>>> Any idea?
>>> Bf-committers mailing list
>>> Bf-committers at blender.org
>> Bf-committers mailing list
>> Bf-committers at blender.org
> Ton Roosendaal Blender Foundation ton at blender.org
> Bf-committers mailing list
> Bf-committers at blender.org
More information about the Bf-committers