Does glass floor allow sunshine to get underground?

[凝滞雪雾]

I want to make my dwarf adapted to sunlight by letting sunshine into my tavern.

[7FOUR]

Yes, and no. For some reason, any tile that has been unroofed even once will be forever considered "light", but whether a tile is considered "indoors" or "outdoors" is always contingent upon whether there is a natural or constructed floor, regardless of material, somewhere above it. At best you'll stall the progression of cave adaptation for as long as your dwarves are on "light" tiles, but resetting it requires them actually being outdoors (no roof whatsoever).

[凝滞雪雾]

Originally posted by Seven Four:

Yes, and no. For some reason, any tile that has been unroofed even once will be forever considered "light", but whether a tile is considered "indoors" or "outdoors" is always contingent upon whether there is a natural or constructed floor, regardless of material, somewhere above it. At best you'll stall the progression of cave adaptation for as long as your dwarves are on "light" tiles, but resetting it requires them actually being outdoors (no roof whatsoever).

So I have to build a skylight. Will floor grate or floor bar counted as a roof?

[Fel]

What you could do it force them to periodically go through a corridor where the whole width (even if only for 1 tile in length) is exposed to the sky.
Since they need to sleep regularly, doing it between your fort and where your bedrooms are.
The wiki pages about cave adaptation and tile attribute can help make sense of it.
https://dwarffortresswiki.org/index.php/Cave_adaptation
https://dwarffortresswiki.org/index.php/Tile_attributes

Most dwarves are fine with getting cave adaptation if they never need to go outside in the first place, so doing something against it isn't a hard requirement.
It also means that flying enemies would have a rather direct path to the center of your fort, which can be quite dangerous.

Rain would also fall on these exposed tiles, depending on the biome, and that causes grumpy thoughts.
In evil biomes with evil rains it would even potentially be deadly.

[7FOUR]

Originally posted by 凝滞雪雾:

Originally posted by Seven Four:

Yes, and no. For some reason, any tile that has been unroofed even once will be forever considered "light", but whether a tile is considered "indoors" or "outdoors" is always contingent upon whether there is a natural or constructed floor, regardless of material, somewhere above it. At best you'll stall the progression of cave adaptation for as long as your dwarves are on "light" tiles, but resetting it requires them actually being outdoors (no roof whatsoever).

So I have to build a skylight. Will floor grate or floor bar counted as a roof?

Unfortunately yes. Completely open air is the only context that allows for a tile to be flagged as outdoors, so it has to be an unobstructed hole. Even a retracted bridge still counts as being an obstacle between the ground and sky.

I agree with Fel that it's a very minor issue, and trying to keep dwarves from cave adaptation in this fashion can result in more annoying or deadlier problems. Few dwarves will need to worry about in the first place. Any professions which have occasion to go to the surface (such as woodcutters, surface farmers, and the haulers collecting their products) will do so often enough to never develop adaptation. Soldiers can train at a surface barracks if you're worried about their performance being affected on the open field, or you can force the enemy to engage your army underground.

[Bystandard]

I like to embark with some cheap blocks. Maybe 50. Then channel a 10X5 into a soil layer. Any depth will do so long as its some sort of soil or mud. Cover up the opening with the blocks as floor. Add a pasture and a few small farms for an monster tight outdoor farm.

Sometimes I get lazy and use existing "ponds" and channel out the area around them to make them square(dwarfy) The loss of water depth is usually enough for it dry out unless its a very wet biome.