There is a blend mode which multiplies the texture color by 2 before applying the multiply blend map to it. This has become popular to use because it works in such a way that where the lightmap is grey, the texture is unaffected, where it is white, it is brightened by 2x, and where it is black the texture is completely dark. Normal lightmapping can only make textures darker than they originall were.
You can probably achieve a similar effect by simply doubling the brightness of all your textures ahead of time.
You might want to do this with some kind of exponential filter though so that you don't lose color information in areas which are already at maximum brightness and get clamping artifacts.
You can also achieve a similar effect by adjusting the gamma ramp as you said.
You can probably achieve a similar effect by simply doubling the brightness of all your textures ahead of time.
You might want to do this with some kind of exponential filter though so that you don't lose color information in areas which are already at maximum brightness and get clamping artifacts.
You can also achieve a similar effect by adjusting the gamma ramp as you said.