Are you facing the mines or not? If you are facing them your character will always report them at 15m but he will not report them if he does not have a mine detector and he's facing away. With mine detector he will report the mine even though he does not see it due to the mine detector.

Thank you for your feedback.

I had the mine 30m directly north of the player, player facing directly north, then moved the player about 3m to the east. Than ran straight forward (just holding W, no mouse movement).

Right now I am not so sure if I had ACE3 running or not (I was doing some tests with it yesterday).

So I reran tests today, this time having the APERS Tripwire Mine (named "mine") 30m directly north of the player, player facing directly south, and once spawned in, running backwards (only holding down S). Ran the following script to display the distance to the mine until detected:

• spawn { while {!(mine mineDetectedBy side player)} do { hintSilent formatText ["%1",player distance mine]; };

};

Mine detector was added / removed to / from inventory after the unit spawned in.

Made sure I had no mods and pretty much got the proper results:

• Rifleman _without_ mine detector, mine exploded
• Rifleman _with_ mine detector, detection range ~15m
• Explosive Specialist _without_ mine detector, mine exploded
• Explosive Specialist _with_ mine detector, detection range ~15m

Now, to figure out what went wrong yesterday (bearing in mind that the test was done slightly different), I turned CBA_A3 and ACE3 back on, then repeated the above tests (running backwards into the mine):

• Rifleman _without_ mine detector, mine exploded
• Rifleman _with_ mine detector, mine exploded
• Explosive Specialist _without_ mine detector, mine exploded
• Explosive Specialist _with_ mine detector, mine exploded

By the way, I was only using the ACE3 medical module (and the dependencies).

The problem seems to be the medical items (in fact all items) created by ACE3, that the unit spawns with. They all inherit from their ACE_ItemCore class and it looks like this:
class CfgWeapons {

class ItemCore;
class ACE_ItemCore: ItemCore {
    type = 4096;
    detectRange = -1;
    simulation = "ItemMineDetector";
};

};

This is no accident as it is a trick to get around Arsenal's limitation of not being able to show generic items.

However, the function used to figure out a unit's mine detection range, is currently stopping at the first "Mine Detector" item it can find and uses its detection range, rather than parsing through the whole inventory to find the item with the best detection range.
Here is how I verified that:
If, after spawning in, I execute

removeAllItems player;
player addItem "MineDetector";
player addItem "ACE_fieldDressing";

and rerun the above tests, I do get a detection range of 15m for both the Marksman and the Explosive Specialist.

If however I change the order and have the ACE item added first

removeAllItems player;
player addItem "ACE_fieldDressing";
player addItem "MineDetector";

both the Marksman and the Explosive Specialist will not detect the mine before stepping onto it.

See issue report over at the ACE3 GitHub for a cleaner version of the report and the ensuing discussion:
https://github.com/acemod/ACE3/issues/879

So its an issue that only happens with ACE3 running?

Yes, its apparently an issue with any mod trying to get their items to show up in Arsenal as items (as there is no such classification at the moment that would show in Arsenal) and are using the mine detector classification as a workaround.

Either we need a way to classify items as, well, just items that would show up in Arsenal, so that way mods can stop classifying their items as mine detectors.

Or we need the function that figures out a units mine detection rate to either keep iterating through all inventory items and pick the item with the best range, or have it at least omit any mine detector item with a negative detection range.

This is a issue with mod, unfortunately we cannot fix this. The mod makers have to fix these issues themselves.

Thank you for your feedback.

Well, yes and no. How are they going to fix this when the game doesn't provide a way to get around this without removing the ability to have items show up in Arsenal?

I agree that the issue isn't the one stated in the opening post, that was before I fully understood what was going on. I or someone from the ACE3 team will probably have to open up a new issue here.

See #23925 for a request to have a "Misc. Item" classification that works with Arsenal.

See #23926 for a request to have the mine detector with the best detection range chosen instead of the first.