sr1 - gamma options

[flipside]

Hi!

I just installed sr1, to play with the new gamma options. I didn't follow the developments here so I'm a bit left out on the new options.

First question. Is the output gamma correction the same as the gamma correction in vray for max under the color mapping section? So it alters the colors during color mapping or is it just previewing the colors gamma corrected (like the srgb button does)?

I assume that correct LDR textures does what is says, meaning that it applies a correction only to LDR textures, so there is no need to apply the correction manually for each LDR texture map?

But then the input gamma is confusing. Wouldn't this do exactly the same, but also to HDR textures? Is it right to say that if all my textures are LDR gamma 2.2, except for HDRI maps (gamma 1.0), that I should set input gamma to 1.0 and correct LDR textures turned on?

Correct RGB seems to me that it applies the gamma correction to the chosen colors (everywhere you choose a color with the color picker).

What about procedural textures and sky map, what happens to them regarding these settings? Are they considered LDR textures, HDR or 'nothing' so that you have to set the gamma correction manually?

Thanks,

wouter

[dalomar_cg]

Re: sr1 - gamma options

First question. Is the output gamma correction the same as the gamma correction in vray for max under the color mapping section? So it alters the colors during color mapping or is it just previewing the colors gamma corrected (like the srgb button does)?

Yes the Gamma correction values function the same as when it was in the color mapping rollout. Meaning that it is affecting the colors during the calculations not just the end result.

I assume that correct LDR textures does what is says, meaning that it applies a correction only to LDR textures, so there is no need to apply the correction manually for each LDR texture map?

Correct

But then the input gamma is confusing. Wouldn't this do exactly the same, but also to HDR textures? Is it right to say that if all my textures are LDR gamma 2.2, except for HDRI maps (gamma 1.0), that I should set input gamma to 1.0 and correct LDR textures turned on?

For proper linear workflow both the input and output gammas should be at the same value and correct LDR textures enabled. The input and output gammas were separated for extra flexability. For the input value, the actual factor it would be changed by is 1/input gamma. If you have the input gamma set to one that will basically act like gamma correcting the output without any of the inputs being affected (i.e. all of the colors/textures will be washed out)

Correct RGB seems to me that it applies the gamma correction to the chosen colors (everywhere you choose a color with the color picker).

Your are correct. This however does not affect colors that are chosen as a representation of values (ie a grey tone for reflection value is not affected).

What about procedural textures and sky map, what happens to them regarding these settings? Are they considered LDR textures, HDR or 'nothing' so that you have to set the gamma correction manually?

Since colors must be selected for procedural maps, those are corrected through the correct RGB option. The Sky is considered an HDR map, therefore it is not corrected and will produce the same result whether the inputs (LDR and RGB) are corrected or not.

Hope this answers all your questions.

[joe_b]

Re: sr1 - gamma options

Also - I consider the use of the texture before I correct it. If you are using it in a spot that isn't truly being used as a "Color" then it will not be corrected. Meaning - a transparency value, or something that is used to blend between material layers but not directly as a color. It is all a bit confusing - perhaps in the future we should stop using "Colors" for things that aren't truly being used as colors. That might make this gamma stuff a little easier to understand.

[Micha_cg]

Re: sr1 - gamma options

...It is all a bit confusing - perhaps in the future we should stop using "Colors" for things that aren't truly being used as colors. That might make this gamma stuff a little easier to understand.

I like the color (triple) multiplier and miss this option at other places sometimes. For example, I would like to multiply textures with a color instead the current single number multiplier. So, color mood of textures could be fine adjusted. Maybe you can integrate chooser for multiplier - color multiplier or single multiplier. For example, right mouse button click at a multiplier and the user can change a multiplier from "single" to "color".