Why is Nyra's Specular Map Blue? I mean it has a blue-ish tint. It's not for specular and gloss because blue also has value. I saw similar in witcher maps. Is there some reason for this?
The basic gist of it is before PBR you had to account for energy conservation in you maps. Energy conservation basically means no more light is leaving an object than it received. So because is so orange you would put blue in the specular to balance the amount of light exiting. The link above explains it well.
No it's not because of PBR, it's because of shaders not doing their lighting calculations in Linear space.
I wasn't saying because of PBR. I was saying *before* PBR. I meant to say that you don't have to do it now with PBR workflows. Energy conservation is now a property of PBR shaders so you don't have to account for that in your maps now. Sorry if I implied otherwise.
EDIT:Or I am mis-understanding you and it's not due to the PBR part, but the switch to linear space that we don't have to do this with our spec maps. Either way my intent was to say that you don;t have to do this with the newer engines. It is going to be an old workflow soon.
Well you are right in saying that with PBR it's no longer a concern; roughness maps are indeed monochrome only.
However, the Linear-space lighting thing is something that was figured out before PBR became all the rage; the article Eric linked is from 2010. Tells you all you need to know about it.
Yeah, as Laurens says it was an issue with renderers working in gamma space, most renderers work in linear space today so you no longer need to use the inverse color to get a white highlight, and in many cases you don't need to use color at all in your specular (certain materials like specific metals or metallic paints do need color specular).
Energy conservation isn't really related in any way.
blue in spec on certain surfaces just looked good. Used it on dark belts & leather all over Gears. White occasionally, but when putting blue spec on a part of a texture my reasons always boiled down to "that looks the best," and made a surface pop off of another.
didn't care if its correct, scientifically accurate, or whatever. doesn't have to have a reason if the end result is pleasing to the eye
blue in spec on certain surfaces just looked good. Used it on dark belts & leather all over Gears. White occasionally, but when putting blue spec on a part of a texture my reasons always boiled down to "that looks the best," and made a surface pop off of another.
didn't care if its correct, scientifically accurate, or whatever. doesn't have to have a reason if the end result is pleasing to the eye
if it looks good, it wins!
+1 don't throw your artistic vision in the trashbin just because PBR is the new thing
Replies
This is a good article on the subject, with nice pictures too.
http://filmicgames.com/archives/299
Also see
Gamma Corrected Specularity here on the forums.
I wasn't saying because of PBR. I was saying *before* PBR. I meant to say that you don't have to do it now with PBR workflows. Energy conservation is now a property of PBR shaders so you don't have to account for that in your maps now. Sorry if I implied otherwise.
EDIT:Or I am mis-understanding you and it's not due to the PBR part, but the switch to linear space that we don't have to do this with our spec maps. Either way my intent was to say that you don;t have to do this with the newer engines. It is going to be an old workflow soon.
However, the Linear-space lighting thing is something that was figured out before PBR became all the rage; the article Eric linked is from 2010. Tells you all you need to know about it.
Energy conservation isn't really related in any way.
http://www.manufato.com/?p=902
Very interesting.
I imagine you could get away with putting colored specular on iridescent surfaces such as mother of pearl, oil slicks, or metallic-looking bugs.
blue in spec on certain surfaces just looked good. Used it on dark belts & leather all over Gears. White occasionally, but when putting blue spec on a part of a texture my reasons always boiled down to "that looks the best," and made a surface pop off of another.
didn't care if its correct, scientifically accurate, or whatever. doesn't have to have a reason if the end result is pleasing to the eye
if it looks good, it wins!
+1 don't throw your artistic vision in the trashbin just because PBR is the new thing
Totally. You may only want to constrain yourself to the laws of PBR if you are attempting to create photo-real art.
However, deviation from reality is part of being an artist!