Dioptra

Dioptra

Creation
Activate protractor Right-click sight Open submenu "Create > Tools"
Total materials
1x Protractor 1x Sight 1x Compass 3x Shaft
Result
Dioptra (0.50kg)
Skill and improvement
Uses blacksmithing skill Improved using blacksmithing tools and materials
Notes
Improve with a bronze lump.

Main / Skills / Smithing / Blacksmithing / Dioptra

Description

An astronomical and surveying instrument, mounted on a tripod.

The dioptra is a tool that, along with a range pole, is used primarily in Cartography and bridge planning. It may also be used to get a general idea of your location by targeting celestial objects like Haven.

Usage

Surveying

A dioptra is utilized by activating it and right-clicking another player holding a range pole. There will be a Survey option with automatic event log messages as follows:

You carefully place the dioptra on its tripod in front of you.
You make sure the dioptra is level.
You point the dioptra at <Player>.
You wave at <Player>.
You line up the dioptra with <Player>.
You look through the dioptra.
You focus on the range pole.
You read the graduations on the range pole and work out the height difference.
<Player> is <xx> tiles <North/South> and <xx> tiles <East/West> of you. Also you appear to be <xx> dirt <higher/lower> than <Player>.
You stop surveying.
You pack up the dioptra.

If your helper is standing in water, you also get the height you are above water.

• Note: Your helper's stamina is drained while they are holding the range pole, which may result in drowning when holding the pole in water.

As your helper is stood in water, you work out how high you are above the water, and it is <xx>.

Can also be used in a cave to determine the slope to the helper holding the range pole.

The range pole is <xx> tiles straight West of you. Also you appear to be <xx> dirt lower than the range pole.

Navigation

Activate the dioptra and right-click any of Wurm's moons or Sol and select Use. Your general geographical location will be displayed in the event window.

You carefully place the dioptra on its tripod in front of you.
You make sure the dioptra is level.
You line up the dioptra with <moon>.
You work out you are in the <location> regions.
You pack up the dioptra.

Bridge planning

A dioptra is utilized by activating it and right-clicking another player holding a range pole. There will be a Plan Bridge option which will proceed to plan the bridge with automatic event log messages as follows:

You carefully place the dioptra on its tripod in front of you.
You make sure the dioptra is level.
You point the dioptra at <Player>.
You wave at <Player>.
You line up the dioptra with <Player>.
You look through the dioptra.
You focus on the range pole.
You read the graduations on the range pole and work out the height difference.
You check the heights of the plan ends.
You appear to be <xx> dirt <Higher/lower> than <Player>.
You work out the orientation and width for the bridge.
You check for clearance between the bridge ends.
You check for protruding foliage.
You check for nearby cave entrances.
You check for any items in the way.
You check that you have permissions to build the bridge.
You check for any bridges that may interfere with this bridge.
You check there would be no buildings under this bridge.
You work out the styles of bridges that would fit.
You start working out the bridge components required.
Planned bridge area is <x> tile(s) long and <x> tile(s) wide.
You stop surveying.
You pack up the dioptra.

Should there be any reason why the bridge can not be planned, it will interrupt the sequence with the appropriate message.

Creation

A dioptra is a somewhat difficult item to make. Assuming you use a sight of about equal quality to your blacksmithing skill it can be created with as low as 30 skill in blacksmithing. It is recommended to improve the sight first before you try to create it in order to increase the success rate. The quality of sight affects creation chance.

• The dioptra uses 0.025 kgs of bronze lump to improve.
• A starter compass may be be used in the creation.
• 90 blacksmithing skill, 14ql sight gives 29% chance
• 66 blacksmithing skill, 14ql sight gives 16% chance; 43ql sight 50% chance
• 55 blacksmithing skill, 28ql sight gives 28% chance
• 42 blacksmithing skill, 42ql sight gives 25% chance
• 31.9 blacksmithing skill, 18ql sight gives 6% chance

Distance

• Maximum measurable distance is based on item quality. The dioptra’s effective range is calculated as:

   maxTiles = QL * 0.4 + rarity

• This value is compared against the actual 3D distance between the dioptra user and the helper, converted to tiles (meters / 4).

• Height difference affects the distance. The game uses full 3D distance (via Creature.rangeTo), so vertical differences (terrain height or floor levels) increase the effective distance. This means a large height gap can cause the measurement to fail even with good tools. (effectively this is a Pythagorean distance: √(dx² + dy² + dz²).)

• If maxTiles < distanceInTiles, the measurement fails. Its almost impossible to stand on the tile borders its best to add 1-2 quality.

• The range pole uses the same formula. The pole has its own independent range check using the same calculation. Both tools must succeed, so the effective maximum distance is the smaller of (including rarity factor):

   min((dioptra max range) , (range pole max range))

• Fine positioning inside a tile affects measurement. Creature.rangeTo uses the creature’s precise world position, not just tile coordinates. Standing slightly closer to the border reduces the distance and can make the measurement succeed at the threshold. To maximize measurement range, stand as close as possible to the tile edge facing the other endpoint.

• These limitations affect only measurement, not bridge length. Dioptra and pole range determine whether the survey can be performed. They do not limit actual bridge construction length — the real bridge length is restricted only by bridge-building rules (span limits, slope limits, section types, etc.).

Additional Notes

• Although brass is used to create the protractor, and bronze is used to create the sight, the finished dioptra tool is bronze and is therefore improved with bronze lump.
• The dioptra has a relatively high value and is worth the same as, for example, mooring ropes and door locks of equal quality. Get price = QL^2 * 0.50.

See also

• Range pole
• Sight
• Protractor

Rare Functionality

Rarity contributes directly to the distance formula:

• rare = +1 tile
• supreme = +2 tiles
• fantastic = +3 tiles

This applies equally to both dioptra and range pole.