Factorio Forums

https://imgur.com/NLk6btI
https://imgur.com/1OQNBon

Spitter range: 13 (wiki)
Ability range: 13 (true)
Damage to 14 distance (no bonus from acid blast... should have been 13?) (something I don't understand)

Turret ranges: 18-24 (gun/laser) (wiki)
Ability range (x-1) (1 range lower) (something I don't understand)

I guessed that the turret range is calculated from 0.0, but when I consider the same logic for a spitter covering a 2x2 area, I see a clear difference. Can you explain this situation?

About the range circle around the turret:
Range is determined from what's considered as center of the turret. The laser/gun turret has size 2x2, so the tiles directly adjacent to the turret outline are already at distance 2, and so the enemy is at distance 25 resp. 19 and cannot be targeted.

About the spitter damaging an item 14 tiles away:
As far as I see, the acid attack of the spitter has AoE damage with range 1 according to the wiki, so the radius for damage is 1 tile more. So if the spitter's range is 13, it's able to attack a target within 13 tiles range, but if it hits a target exactly 13 tiles away this hit will also damage additional items within 1 tile range of that target, which might be out of the 13 tiles range at distance 14.


What you show is a very good example what range considerations to include into a defense design. The outermost defense building must be near enough to your turrets that spitters attacking this building can be reached by the turrets. The destroyed belt on the left (the one with the acid puddle over it) is 1 tile too far. If it doesn't exist, the spitter would move 1 tile nearer and the turret would be able to attack the spitter.

The first message contained a very poor and inaccurate translation... I want to reiterate:

The ONLY thing I still find strange at this stage is that the range measurement for turrets is done from the "CENTER," while the range for spitters is done according to the "OUTER END POINTS." Because ultimately, aren't both turrets and spitters essentially entities?

So why isn't the range calculation method the same for a spitter occupying 2x1 space and a turret occupying 2x2 space? For a spitter, we count 1-2-3... from the outer edge, but for the player's turrets, we start the range calculation from the center.

Understanding range is easy: range 0 is the same tile, range 1 is the next tile and so on.

About hitting: as far as I know, this is calculated according to the collision box of an entity, which is some kind of area around the center. Shooting takes always place from the center, not from the edge. It's a design decision that makes range calculations easy. If you want to shoot from the edge of your collision box, you just need to add the radius of your own collision box to the range to get the same result, so just setting a range from the center is an equivalent but simpler implementation.

The first message contained a very poor and inaccurate translation... I want to reiterate:

The ONLY thing I still find strange at this stage is that the range measurement for turrets is done from the "CENTER," while the range for spitters is done according to the "OUTER END POINTS." Because ultimately, aren't both turrets and spitters essentially entities?

So why isn't the range calculation method the same for a spitter occupying 2x1 space and a turret occupying 2x2 space? For a spitter, we count 1-2-3... from the outer edge, but for the player's turrets, we start the range calculation from the center.