Same specular map, wildly different results. How can I fix this?

[Some_stranger]

Hello.  Keep in mind I am using PartTools etc, KSP shaders, all that.  If I use the shader that uses a specular alpha channel for the diffuse, it looks terrible.  If I use the specular as a seperate channel entirely (mapped), it looks pretty much how I'd want it to.  Is there any reason for this?  Working with source engine, this was never an issue.  I feel like it's a problem with the shader itself and not the textures I'm using.

 

Here's an image reference.

Here's the textures.

 

Let me know if you need any more info.  Any help would be grand.  Cheers.

[doodlemh]

only thing i can think of is that one has specular one has diffuse lighting 
edit: im late but i guess its too late for me to go back now

 

Edited July 14, 2019 by doodlemh

[Shadowmage]

On 6/16/2019 at 3:18 PM, Some_stranger said:

Hello.  Keep in mind I am using PartTools etc, KSP shaders, all that.  If I use the shader that uses a specular alpha channel for the diffuse, it looks terrible.  If I use the specular as a seperate channel entirely (mapped), it looks pretty much how I'd want it to.  Is there any reason for this?  Working with source engine, this was never an issue.  I feel like it's a problem with the shader itself and not the textures I'm using.

 

Here's an image reference.

Here's the textures.

 

Let me know if you need any more info.  Any help would be grand.  Cheers.

Different shaders.  The specular-in-alpha channel is a legacy shader, using basic Lambert lighting (or some derivative/relative).  The (mapped) shader uses a (hacked/partially implemented) form of PBR lighting, and uses global-illumination and environment lighting in its calculations.

(Kind of guessing here that you are referring to the two different shaders 'KSP/Bumped Specular' and 'KSP/Bumped Specular (mapped)')

Background:  I know a thing or three (or ten) about Unity and KSP shaders.