Arma 3: Multi-Function Display (MFD) config reference

MFD (Multi-Function Display) is implementation of HUD (Head-Up Displays) in Arma 3. Display can be fixed on helmet (move with player head) or cockpit (static position). THIS PAGE IS WORK-IN-PROGRESS, USE AT YOUR OWN RISK.

Technical Basics

HUDs are defined in the MFD class of the source vehicle. The properties of each HUD are separated by a root class (conventionnally named AirplaneHUD in base content), although each new instance will render a new HUD and overlap with the previous. This makes it easier to configure HUDs by modular config (for example, navigation, targeting, etc...). All HUDs are defined through 3 base elements :

• Bones : invisible elements used to transform/rotate other, similar to anchors/origins. Defined in the Bones class of any HUD.
• Drawn elements : used to draw graphic elements. Defined in the Draw class of any HUD.
• Sources : if an element displays complex variables or any bone needs to be in specific positions, it uses a source data. Defined in each instance of bone and draw classes when needed.

Example :

class MFD {
	class AirplaneHUD {
		globalProperty = ...; // global HUD properties
		// bones definitions
		class Bones {
			class BoneInstance {
				type = ...; // type of bone
				source = ...; // source for bone transformation
				properties = ...; // other bone properties
			};
		};
		// HUD-Elements definitions
		class Draw {
			class HUDElemetInstance {
				type = ...; // type of HUD-Element
				source = ...; // source for display value
				properties = ...; // other HUD-Elements properties
			};
		};
	};
};

Global HUD Properties

These are defined in each AirplaneHUD instance and affect every sub-sequent element. Some properties can be overwritten in each child element if needed (e.g color) :

• color : [r,g,b,a] - color of all elements.
• topLeft : "string" - memory point defining the top left position of the HUD and uses it as the absolute origin (0,0,0). Not used if helmetMountedDisplay = true.
• topRight : "string" - memory point defining the top right position of the HUD and uses it as the far right limit (1,0,0). Not used if helmetMountedDisplay = true.
• bottomLeft : "string" - memory point defining the bottom left position of the HUD and uses it as the bottom limit (0,1,0). Not used if helmetMountedDisplay = true.
• borderLeft : float - adjust position inside of memory points LOD. Not used if helmetMountedDisplay = true.
• borderRight : float - adjust position inside of memory points LOD. Not used if helmetMountedDisplay = true.
• borderTop : float - adjust position inside of memory points LOD. Not used if helmetMountedDisplay = true.
• borderBottom : float - adjust position inside of memory points LOD. Not used if helmetMountedDisplay = true.
• fontHelicopterHUD : "string" - font used for this HUD instance.
• helmetMountedDisplay : true/false - Defines if the HUD is attached to a fixed point of the aircraft or moves with the head of the pilot.
• font: "string" font type used for drawing HUD elements
• turret: "array" {-2} - default, legacy behaviour, {-1} - remote controled weapons, {} - same as -2, {0} - turret path

Bones

Bone defines position of graphic element. Final position can be modified by sources in each frame. Bones have no hierarchy, hierarchical geometry is available by chain of bones in HUD-element draw. Currently there are 6 types of bones: fixed, linear, rotational, horizon, vector and ILS. Bones type is defined by type property in bone class (e.g.: type = fixed;). Bones types:

• Fixed: represents a fixed position on HUD plane. It can be use for static HUD-Elements (e.g.: aiming cross).
  • pos ([x, y]): position of center (left top corner is [0,0], right bottom corner is [1, 1])
• Linear: represents a linear transformation depend on source float value. It can be used for some linear indicator (e.g.: fuel bar).
  • source (string): name of float source value. See sources for more details
  • min (float): minimal valid source value. Lower source value will be forced to minimal
  • max (float): maximal valid source value. Higher source value will be forced to maximal
  • sourceScale (float): multiplier of source value. It is optional, default is 1
  • minPos ([x, y]): position for maximal source value (minPos matches max source value - for historical reasons)
  • maxPos ([x, y]): position for minimal source value (maxPos matches min source value - for historical reasons)
• Rotational: represents a rotational transformation depend on source float value. It can be used for some rotational indicator (e.g.: analog speedometer).
  • source (string): name of float source value. See sources for more details
  • min (float): minimal valid source value. Lower source value will be forced to minimal
  • max (float): maximal valid source value. Higher source value will be forced to maximal
  • sourceScale (float): multiplier of source value. It is optional, default is 1
  • center ([x, y]): position of center of rotation
  • minAngle (float): angle (in degrees) for minimal source value
  • maxAngle (float): angle (in degrees) for maximal source value
  • aspectRatio (float): rotation aspect ratio. It is optional, default is 1
• Horizon: represents a transformation for horizon indicator.
  • angle (float): angle of horizon line (degrees)
  • pos0 ([x, y]): scene to HUD plane transformation. For more details, see here.
  • pos10 ([x, y]): scene to HUD plane transformation. For more details, see here.
• Vector: represents a transformation from scene position (depend on source type) to HUD plane. Properties:
  • source (string): name of 3D vector source value. See sources for more details
  • pos0 ([x, y]): scene to HUD plane transformation. For more details, see here.
  • pos10 ([x, y]): scene to HUD plane transformation. For more details, see here.
• ILS: represents transformation for ILS (Instrument landing system). Properties:
  • pos0 ([x, y]): scene to HUD plane transformation. For more details, see here.
  • pos3 ([x, y]): scene to HUD plane transformation. For more details, see here.
• Limit: saturate preview vector transformation by box
  • limits ([x0, y0, x1, y1]): bounding box in HUD coordinates 0 -1.

HUD Elements

HUD Element represents one graphic entity. It defines what and how will be drawn. Currently there are 5 types of HUD-Elements: line, text, scale, radar and group. Group element has no geometry, it is because elements hierarchy. HUD Elements type is defined by type property in HUD Element class (e.g.: type = line;). HUD Elements types:

• Line: draws lines (or multi-lines) defined by points.
  • points (array): For more details, see here.
  • width (float): width of line segments
• Text: draws value depend on source as text
  • align (string): text alignment. Valid options: left, right, center.
  • scale (float): font size
  • source (string): name of string source value. See sources for more details
  • sourceScale (float): multiplier of source value. For non static source only
  • sourceLength: format source value: number of characters to draw , rest filled with "0"
  • sourcePrecision: format source value: number of characters afters decimal dot.
  • refreshRate: refresh rate of source ranging from 0 to 1s. Can be used to simulate old MFDs with low FPS

• • text (string): static text to draw. For static source only
  • pos (array): position of text. It is the same as one point in line definition. For more details, see here.
  • right (array): right direction of text. It is the same as one point in line definition. For more details, see here.
  • down (array): down direction of text. It is the same as one point in line definition. For more details, see here.
• Scale: is horizontal or vertical bar indicator. Scale HUD-Element can't use bones for transformation.
  • align (string): text alignment. Valid options: left, right, center.
  • scale (float): font size
  • source (string): name of float source value. See sources for more details
  • NeverEatSeaWeed (integer): 1 - will show "N,E,S,W", 2 - will show "N,NE,E,SE,S,SW,W,NW" in the heading scale
  • sourceScale (float): multiplier of source value
  • horizontal (bool): true for horizontal bar, false for vertical bar
  • pos ([x, y]): position of text item related to top position. It is for text range definition, final position of text will be move to related line.
  • right ([x, y]): right direction of text item related to top position.
  • down ([x, y]): down direction of text item related to top position.
  • step (float): amount of source between two lines.
  • stepSize (float): length between two lines.
  • lineXleft (float): left/top position of one normal line in vertical/horizontal bar
  • lineYright (float): right/bottom position of one normal line in vertical/horizontal bar
  • lineXleftMajor (float): left/top position of one major line in vertical/horizontal bar
  • lineYrightMajor (float): right/bottom position of one major line in vertical/horizontal bar
  • top (float): top position of bar indicator (left for horizontal indicator)
  • bottom (float): bottom position of bar indicator (right for horizontal indicator)
  • center (float): center position of bar indicator
  • majorLineEach (int): granularity of major lines
  • numberEach (int): granularity of lines with text value
  • min (float): min valid value, lower values will be ignored. min value is already affected by sourceScale
  • max (float): max valid value, higher values will be ignored. max value is already affected by sourceScale
• Radar: draws geometry around entities
  • pos0 ([x, y]): scene to HUD plane transformation. For more details, see here.
  • pos10 ([x, y]): scene to HUD plane transformation. For more details, see here.
  • points (array): defines graphics which will be rendered around each entity. For more details, see here.
• RadarToView: (for HMD) uses same parameters as radar.
• Group: makes HUD-Elements hierarchy. It can change attributes for its child elements. Group element has no graphics.
  • color ([r, g, b, a]): color of HUD-Elements graphics
  • alpha (int: 0-255): alpha of HUD-Elements graphics
  • clipTL ([x, y]): top left corner of clipping area (range is [0, 0] - [1, 1])
  • clipBR ([x, y]): bottom right corner of clipping area (range is [0, 0] - [1, 1])
  • condition (string): condition for enable/disable child elements. Since 1.69 it's also possible to use float sources (like "speed", "rpm", etc.) as a condition & math commands. Available conditions:
    • on: engine is on
    • ils: ILS system is activated
    • mgun: machine gun is selected
    • missile: missile is activated
    • aamissile: air lock air missile
    • atmissile: air lock ground missile
    • rocket: rocket is selected
    • bomb: bomb is selected
    • flaps: flaps out (for airplanes only)
    • lights: landing lights are on
    • collisionlights: anti-collision lights are on
    • stall: plane stalling (for airplanes only)
    • simulArma: standard helicopter simulation (for helicopters only)
    • simulRTD: advanced helicopter simulation - RTD (for helicopters only)
    • incomingmissile: you are locked by incoming missile
    • missilelocking: locking of your missile is in progress
    • missilelocked: missile is locked
    • wpvalid: unfinished waypoint[s]
    • laseron: laser designator is activated
• blinkingPattern ([intervals]): define blinking pattern for group HUD elements. combination with condition is possible.
  • blinkingStartsOn (bool): define blinking state on beginning

Sources

Source represents value which can modify position of some types of bounds (e.g.: angle of analog speedometer pointer) or value of some HUD elements (e.g.: altitude as text, heading bar direction, etc.). Currently there are 3 types of sources: float, 3D vector and string. Sources type is defined by source property in bone or HUD Element class (e.g.: source = speed;). Sources types:

• Float: source represents numeric value. It is used by Linear and Rotational bones and Scale HUD-Elements. Available values:
  • altitudeAGL: altitude above ground level (m)
  • altitudeASL: Altitude above sea level (m)
  • coordinateX: X coordinate of plane position in the world (m)
  • coordinateY: Y coordinate of plane position in the world (m)
  • speed: speed of airplane (m/s)
  • rpm: revolutions per minute of engine
  • vspeed: vertical speed (m/s)
  • fuel: fuel state (0-1)
  • targetDist: distance to target (m)
  • impactDistance: distance to impact point (m)
  • heading: heading of airplane (degrees)
  • cameraDir: direction of head (degrees)
  • horizonBank: horizon bank of airplane (radians)
  • horizonDive: horizon dive of airplane (radians)
  • windage: direction of wind (degrees)
  • rtdCollective: collective state (0-1) - value is valid for helicopters with advanced RTD simulation only
  • rtdRotorTorque: rotor torque state (0-1) - value is valid for helicopters with advanced RTD simulation only
  • rtdGForce: actual G-Force value - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm1: scaled revolutions per minute of engine #1 - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm2: scaled revolutions per minute of engine #2 - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm3: scaled revolutions per minute of engine #3 - value is valid for helicopters with advanced RTD simulation only
  • ClockHour: time of day on scale (0-1) consistent with clockHour animation source (that means 12 hours cycle)
  • ClockMinute: time of hour on scale (0-1) consistent with clockMinute animation source
  • ClockSecond: time of minute on scale (0-1) consistent with clockSecond animation source
  • WPDist: distance to current waypoint/steerpoint
  • WPIndex: index of next waypoint
  • MissileFlightTime: expected time to impact target
  • AoA: plane Angle of Attack
  • gmeter, gmeterX, gmeterY, gmeterZ: G-forces
  • gmeterGrav, gmeterXGrav, gmeterYGrav, gmeterZGrav: G-forces + gravitational force

• 3D Vector: source represents 3D vector value. It is used by Vector bone only.
  • velocity: velocity of airplane
  • velocityToView: velocity of airplane transformed to current view (for HMD) - don't combine with forward transformation!
  • target: locked target position
  • targetToView: locked target position transformed to current view (for HMD) - don't combine with forward transformation!
  • weapon: primary gun direction
  • weaponToView: primary gun direction transformed to current view (for HMD) - don't combine with forward transformation!
  • forward: forward direction of airplane
  • impactpoint: position of CCIP (constantly computed impact point)
  • impactpointtoview: CCIP for HMD
  • wppoint: position of next waypoint
  • wppointtoview: position of next waypoint (for HMD)
  • pilotcamera: Targeting Pod aim direction
  • pilotcameratoview: Targeting Pod aim direction - HMD variant
  • LarTop: missileLockMaxDistance rounded up to 1000,2000,5000,10000,15000, etc.
  • LarAmmoMax: missile lock maximal distance - reading missileLockMaxDistance from cfgAmmo
  • LarAmmoMin: missile lock minimal distance - reading missileLockMinDistance from cfgAmmo
  • LarTargetDist: relative distance to target
  • LarTargetSpeed: relative speed to target
  • airportCorner1, airportCorner2, airportCorner3, airportCorner4: airport corners

• String: source represents string value from numeric value (extended float values). It is used by Text HUD_Element only.
  • altitudeAGL: altitude above ground level (m)
  • altitudeASL: Altitude above sea level (m)
  • coordinateX: X coordinate of plane position in the world (m)
  • coordinateY: Y coordinate of plane position in the world (m)
  • speed: speed of airplane (m/s)
  • rpm: revolutions per minute of engine
  • vspeed: vertical speed (m/s)
  • fuel: fuel state (0-1)
  • targetDist: distance to target (m)
  • heading: heading of airplane (degrees)
  • horizonBank: horizon bank of airplane (radians)
  • horizonDive: horizon dive of airplane (radians)
  • windage: direction of wind (degrees)
  • rtdCollective: collective state (0-1) - value is valid for helicopters with advanced RTD simulation only
  • rtdRotorTorque: rotor torque state (0-1) - value is valid for helicopters with advanced RTD simulation only
  • rtdGForce: actual G-Force value - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm1: scaled revolutions per minute of engine #1 - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm2: scaled revolutions per minute of engine #2 - value is valid for helicopters with advanced RTD simulation only
  • rtdRpm3: scaled revolutions per minute of engine #3 - value is valid for helicopters with advanced RTD simulation only
  • weapon: weapon name
  • ammo: amount of ammunition and magazine
  • static: static text defined in config by text property

Scene To HUD Transformation

Transformation of 3D vector from scene to 2D vector on HUD plane is implemented by two 2D vectors:

• pos0: 2D position on HUD plane of ray defined by source (center)
• pos10: 2D position on HUD plane of ray, which have angle to previous ray 10 degrees in axes X and Y
• pos3: the same as pos10, but angle is 3 degrees only. It is used in ILS.

Example :

class Velocity {
	type = vector;
	source = velocity;
	pos0[] = {0.5, 0.5}; // center of HUD for source vector
	pos10[] = {0.2, 0.2}; // 20% offset for 10 degrees vector
};

Points Definition

Lines (or multi-lines - line with more segments) are defined by array of points. In one points array can be defined more lines. Lines must be splitted by separator. Each point can be transformed by more bones (bones chain).

• Point: defines one point of line. Point is define as chain of triplets (see next bullet: Bones chain). Triplet defines one transformation step of point:
  • bone name (string): name of bone for point transformation. Bone name is optional, but one of bone name or offset must be defined.
  • offset ([x, y]): offset applied to transformation. Offset is optional, but one of bone name or offset must be defined.
  • weight (float): weight to multiply transformation, must be defined.

points[] = {
	{boneName, {offsetX, offsetY}, weight}, // full definition
	{{offsetX, offsetY}, weight}, // without bone
	{boneName, weight}, // without offset
	{boneName, {[boneName transform only coordinates in this group],0, 0}, weight}, // the same as previous one
	{1} // ERROR: weight only
};

• Bones chain: each point can be transformed by more bones. Transformation chain is defined as array of triplets. Transformation order is from left to right. Example (without offsets to simplify):

points[] = {
	{bone, 1}, // 1 transformation
	{bone1, 1, bone2, 1}, // 2 transformations
	{bone1, 1, bone2, 1, bone3, 1} // 3 transformations
	// etc...
};

• Line: points array with more than 1 point defines line (or multi-line with more than 2 points). See example below.
• Separator: in one points array can be defined more lines. Lines must be splitted by separator. Separator is empty array {}.

example:

points[] = {
	// one-segment line
	{bone, {0, 0}, 1},
	{bone, {1, 1}, 1},
	{}, // lines separator
	// rectangle: 4-segments multi-line
	{bone, {0, 0}, 1},
	{bone, {1, 0}, 1},
	{bone, {1, 1}, 1},
	{bone, {0, 1}, 1},
	{bone, {0, 0}, 1}
};