Texture Modding Help please .. SPECULARS Values in .mtl file ?

[RagTag]

Enjoying the game and loving the opportunity to learn a bit about texturing at the same time.

One of the most intriguing areas is that of skin / material glossiness and I can sort of see the basics of it with the skin's specular map and its pointer in the .MTL file.

Although there are quite a few good explanations of how the specular properties are achieved (in the RGB channels) the I've not yet been able to find an explanation of what each of the specular values do in the .mtl file. For example

speculars 0.5 1.0 0.0;

Sure enough, If you change these values you can get some interesting results but without knowing what they actually control its pure guesswork.

Could someone kindly give me a definitive answer as what these 3 values do and their upper/lower limits ?

Thanks in advance

[antales]

The specular map consists of three parameters: roughness, intensity, metallness. Unfortunately PBR was never fully implemented in Haydee engine so metallness parameter does not work properly. So we advice not to use it (keeping zero).

Intensity paramener means how much specular this material has. The higher it is the brighter specular you would have.

Roughness defines the type of the specular. Lower values correspond to mirror-like (smooth) surfaces, and higher ones to diffuse (rought) surfaces. So if you want something glossy you should use lower roughness values. If you want something matte then use higher values.

Also .mtl files use specular maps (or textures) which define specular properties for each pixel of the surface and also specular multipliers (for multiplying values from the map).

Was that definitive enough? :)

[RagTag]

Thanks Antales, very much appreciated and Yes, very thorough. Great game, it’s good to have the ability to enjoy “as is” but at the same time enjoy a bit of tweaking too.

I guess all this curiosity came about when I was looking though the excellent gallery pictures and taking an instant liking to those costumes that were super glossy, thinking that I’d have a go at adjusting some of the downloadable outfits in the same way.

So it just leaves me with a question about how I go about adjusting the 3 .specular values to get the desired effect.

If I can give you an example.. somewhere amongst the many downloadable outfit packs is a file called Class_PaintedOn.ShineList

..although not labelled as an .MTL file I gather that it plays its part in a similar way. In the file are many (specular?) entries. A few, for example are

MrEffLatexTnA\Suit_S.dds
2.0
2.55
2.55
Latex

N/A
0.1
1.0
0.0
Wet

N/A
0.3
1.0
0.0
Oily

.. so taking for example this last one, what do the 0.3, 1.0 and 0.0 values actually refer to?

So say for instance, If I play around with it and change the 0.3 value to 0.2, is this controlling (ie lightening /darkening ) say the first of the RGB layers in the suit_s.dds file ??? (similarly with the others?)

I’m trying to get an understanding of whether I need to have a go at editing the actual suit_s.dds in photoshop or do I get the desired glossy effects by playing around with the 3 specular values in a “hit and miss” fashion ?

[antales]

I kinda don't understand the context. What file is it from? Could you provide a quote from the file?

[RagTag]

That particular file is from a pack which I believe has now disappeared but any of the .mtl files would do as an example.. for instance the "suit.mtl" in the haydee folder as follows

HD_DATA_TXT 300
material
{
type OPAQUE;
twoSided false;
width 64.0;
height 64.0;
normalMap "Outfits\Haydee\Suit_N.dds";
diffuseMap "Outfits\Haydee\Suit_D.dds";
specularMap "Outfits\Haydee\Suit_S.dds";
speculars 1.0 2.0 0.0;
surface Default;
}


.. the line ..

speculars 1.0 2.0 0.0;

what do the 3 parameters (1.0 2.0 0.0 ) refer to ?

I can see that haydee's skin goes more or less shiny when I change these values and save the file but I want to know what they are actually changing (controlling)..

..I'm guessing it's something in the specular map.. either some characteristics of the file itself (Suit_S.dds) like the intensity of the RGB channels perhaps ??or it's something that the game engine does at run time ???

If I change the first value, from 1.0 to 0.15 and save the file I see that the skin goes from dull shiny but how is that achieved ?. I've not made any changes to the suit_s.dds file in photoshop so what happens?

[RagTag]

..and just as importantly.. do I ever need to edit the suit_s.dds in photoshop or is it best left alone ?? ..sorry if it does sound confusing.. don't forget I'm still rather new to the world of texturing!!

[antales]

As I explained previously, they are: roughness, intensity and metallness. The line "speculars 1.0 2.0 0.0;" contains multipliers for the specular map "Outfits\Haydee\Suit_S.dds". So the game gets a sample from that texture and multiplies each channel to corresponding multiplier. R * 1.0 (roughness would be the same), G * 2.0 (intensity would be doubled) and B * 0.0 (metallness would not matter).

[RagTag]

I get you now, understood. Thank you very much for clarifying that and the detailed information, much appreciated :)