On 10/19/2016 11:15 AM, scott wrote:
>> With the recent discussions related to gamma handling I thought I'd post
>> an image comparing how transmit behaves with respect to assumed_gamma in
>> a texture overlaid upon an image base texture. The behavior of transmit
>> at an assumed_gamma (ag) of 1.0 is something I like less well than its
>> behavior at an ag of 2.2.
>
> Is the problem here though is that you're trying to solve this by
> tweaking gamma? Maybe it works for this issue, but it's also going to
> affect all the other lighting and colours in your scene.
>
> The better approach would be to figure out how to achieve what you want
> without changing the scene-wide gamma setting. What if you adjust the
> gamma of the image and the "gamma" of your rgbt values (ie don't step in
> equal steps for each column)? You might have to sit down and work out
> the maths to get what you want without changing assumed_gamma.
>
Indeed, you can make adjustments to colors and transmit instead to 
mostly get there in the 1.0 space. Inserting additional transmit entries 
in the map often helps - sort of a piecewise, linear curve approach.

To be clear, I'm not tweaking assumed_gamma for effect. I use an ag of 
1.0 for all my work.

That said, I've spent a fair bit of time working through Norbert's 
material collection - mapping them to my own ag 1.0 versions and 
variants. I've been doing it as a way to learn from other's texturing 
work as much as anything. In my own work, I've hit upon occasions where 
I want a less linear and tighter blend between textures. The 2.2 space 
offers some of this - I suspect by side effect as much as intent.

With my post I was trying to document a texture layering difference 
between the gamma spaces I think real. One that can be a speed bump of 
sorts - especially when converting ag 2.2 developed overlapping textures 
to an ag of 1.0 working space.

Bill P.

Post a reply to this message