@BitVenom, and others: I tracked down the problem...
Line 332 of data:shaders/gl_prog/sob_ship.frag:
float isPaint = texGlow.g;
Asteriods don't get painted (typically), so the G channel of the glow texture (which, in the case of the
ore surface shader, is actually a combination of the REFL, PAIN, and SPEC maps in the R, G, and B channels, respectively) is defaulted to 0 (for no paint). This is totally fine.
texGlow.g = 0.0;
This would seem innocuous, if it weren't for the fact that this value gets used further down on line 398:
float mapGlowMask = texGlow.g;
texGlow.g to 0, we are telling the shader to not use the glow mask, which, at lines 452, 493-494, 500, and 604, results in a zero for the glow color addition.
452: float glowStrength = mapGlowMask*max(0.0, extGlowPower-(extGlowFren*frenDeg));
493: vec3 diffRGB = paint.rgb;
494: vec3 glowRGB = texGlowRGB.rgb*0.8;
500: glowRGB *= glowStrength;
604: paint.rgb = (diffRGB*diffAll)+glowRGB+(specAll*specStrength);
Changing line 333 to
texGlow.g = 1.0; fixes the issue.
P.S.: I even extracted a clean version of the file from the archive, just to make sure I hadn't screwed something up with the file I had previously extracted. Same results.