What version are you using?

Forge: 1.12.2-forge-14.23.5.2854
Dynamic Darkness: darkness-forge-1.12.x-0.4.2
Optifine: OptiFine_1.12.2_HD_U_G5

Texture Pack:
John Smith Legacy - Modded

Does this issue reproduce with the latest release?

Since 0.4.2 is the latest, yes

Which other mods do you have installed?

Optifine

What did you do?

Just add the mods and the texture pack and enter to a cave, you will see how everything is still visible

What did you expect to see?

A total Darkness

What did you see instead?

The minimum illumination

Additional Notes

well, this can be fixed by removing the lightmaps inside the texture pack, but if you manage to do it, it would be great to be able to use the LightMaps and still having that amazing total darkness of Dynamic Darkness.

i really like the red-ish effect of the light maps in that texture pack, but the effect of total darkness is more valuable, anyways having the best of both worlds would be amazing

@gatoborrachon, I’ve actually never used any texture packs in Minecraft. 😅
Are custom LightMaps a vanilla feature?

if i recall correctly, lightmaps were born in MCPatcher (the same name of the folder where they are inside the texture pack i mention above), and then Optifine started to use them (i can confirm this by using the Texture pack without optifine, i don't get the effect of the lightmaps (that red-ish color in the first pic)

i made some tests with combinations of the Texture pack (with Lightmaps enabled and disabled), Optifine and Dynamic Darkness, but the most important results are here: (set your screen to the maximum brightness to notice the results, all the pics were took with /time set 12700)
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(the lightmaps are here: JSTR_Modded_Universal.zip\assets\minecraft\mcpatcher\lightmap, but i don't think that this info will be useful)

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1.- LightMaps (Texture Pack) only: (you can see how it does not have that red-ish color, since the lightmaps only work with Optifine)

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2.- LightMaps + Optifine: (now you can see the red-ish color)

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3.- LightMaps + Optifine + Dynamic Darkness (basically, it's like the previous pic, when i had not Dynamic Darkness)

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4.- NO Lightmaps + Optifine + Dynamic Darkness: (if you compare this one with the pic number 1, you can see how things are more darker, showing that LightMaps break totally the Dynamic Darkness effect)

also, another modder told me that Vanilla does not use lightmaps, and after some investigation for other way to get this amazing black pitch effect, i saw that you can "imitate" it with LightMaps
(Pitch Darkness (a texturepack for 1.16+), MAGE and Advanced Darkness use this method by the result you get with them)

but the result is a total and uncomfortable darkness, it seems a little bit artificial (and you don't have the Moon Phase Dynamic Brightness)

and as a personal conclusion (from a dude with almost zero knowledge about coding), i think that, whatever are the lightmaps, if a texturepack uses them, it will make Optifine to use an "alternative" way to work light (because as far as i know, lightmaps are sprites that you put over textures to "imitate" light, like the game Quake 2 does with proyectiles), and consequently breaks Dynamic Darkness since it was not designed to work with this "alternative" way of Optifine