Problems with Specular Maps ..

[skellborn]

Hi there,

me and a friend are trying out our own mod for some ideas we have in mind. Right now everything works well, except the specular maps. Unfortionately the link provided in the sticky by HawkGear doesn't work anymore
Right now it feels like a gamble wether it looks alright or not...
We're both using Gimp2.
Is there someone who could explain to us, what exactly is important and how it is best to manipulate R G B and A?
It would be very much appreciated!
Thanks guys

[Florenzius]

a specular map is just a grey scale map where white represents high specularity and black represents 0 specularity. you could make one in paint.

What matters is how your shader uses that map to produce the effect.

http://lmgtfy.com/?q=gimp+specular+map

4th link ^^

It was easy

[skellborn]

Well okay thanks
But i feel like this doesn't help that much. It could be because i have no idea what i'm talking about, but I tried to make everything black just to see if the glance goes away, which it doesn't...
If i look at specular maps of other mods, they are coloured and with that faaar away from being black/white.

[Electron]

Take a look at this great posting from Fix.

Start with a copy of the diffuse map. Set the blue and alpha component to 0. Then adjust R and G so that plain areas like platforms and tarmac roads reflect the sun/moon light properly. Then select areas like windows or metal parts and increase both values, so they reflect the light more. This gives relatively good results. You can fine tune the map by modifying all RGBA components separately (accordingly to Fix posting).

Note that the specular and normal maps depends one each other. Watch out that the edges on the normals don't outshine. Contrariwise a to dark S map reduces the 3D effect of the N map.

Note also that you need to calculate the lightmap after each change.

[skellborn]

Thank you
One question remains:
Do i need transparency at all? Pretty much all specular maps i've seen for some mods are more or less transparent. But if i understand it right, it's only about the degree of colour...?
Also one more thing (and this may seem like a really stupid question, but i'm a real nub in these things )
He talks about the individual channels and black being "nothing" and white being "max". However, to my understanding (for example for the red channel) the colours can only range from black to red, so no white being included. I guess with white (max) he means the belonging colour of the channel?

[Electron]

The alpha channel controls the glossynes (see 3-Microsurface in Fix posting). Because the game engine quickly tends to outshine everything I always start with 0x00 = black = transparent or a very dark copy of the diffuse map.

Every component of the RGBA bitfield represents a separate property with a value between 0 and 255 (or min and max or black and white of a 8-bit grayscale bitmap that represents a single channel).
Completely forget the word color while editing S-maps and replace Red, Green and Alpha with Fresnel, Intensity and Exponent.

Using the following Website you can learn live what normal and specular maps are and how the different parameters effect the display of objects:
http://cpetry.github.io/NormalMap-Online/