RenderableNodeArrow

Inherits Renderable

A RenderableNodeArrow can be used to create a 3D arrow pointing in the direction of one scene graph node to another.

The arrow will be placed at the StartNode at a distance of the provided Offset value. Per default, the Length and Offset of the arrow is specified in meters, but they may also be specified as a multiplier of the bounding sphere of the StartNode. The look of the arrow can be customized to change the width and length of both the arrow body and head.

Members

Name	Documentation	Type	Description	Optional
EndNode	The identifier of the node the arrow should point towards.	Identifier	An identifier string. May not contain ‘.’, spaces, newlines, or tabs	No
StartNode	The identifier of the node the arrow starts from.	Identifier	An identifier string. May not contain ‘.’, spaces, newlines, or tabs	No
AmbientIntensity	A multiplier for ambient lighting for the shading of the arrow.	Double	Greater or equal to: 0	Yes
ArrowHeadSize	The length of the arrow head, given in relative value of the entire length of the arrow. For example, 0.1 makes the arrow head length be 10% of the full arrow length.	Double	Greater or equal to: 0	Yes
ArrowHeadWidthFactor	A factor that is multiplied with the width, or the arrow itself, to determine the width of the base of the arrow head.	Double	Greater or equal to: 0	Yes
Color	The RGB color for the arrow.	Color3	Value of type ‘Color3’	Yes
DiffuseIntensity	A multiplier for diffuse lighting for the shading of the arrow.	Double	Greater or equal to: 0	Yes
Invert	If true, the arrow direction is inverted so that it points to the start node instead of the end node.	Boolean	Value of type ‘Boolean’	Yes
Length	The length of the arrow, given either in meters or as a factor to be multiplied with the bounding sphere of the start node (if ‘UseRelativeLength’ is true).	Double	Greater or equal to: 0	Yes
Offset	The distance from the center of the start node where the arrow starts. If ‘UseRelativeOffset’ is true, the value should be given as a factor to multiply with the bounding sphere of the node. Otherwise, the value is specified in meters.	Double	Value of type ‘Double’	Yes
PerformShading	Determines whether shading should be applied to the arrow model.	Double	Value of type ‘Double’	Yes
Segments	The number of segments that the shapes of the arrow are divided into. A higher number leads to a higher resolution and smoother shape.	Integer	Greater or equal to: 3	Yes
SpecularIntensity	A multiplier for specular lighting for the shading of the arrow.	Double	Greater or equal to: 0	Yes
UseRelativeLength	Decides whether to use relative size for the length of the arrow. This means that the arrow length will be computed as the provided ‘Length’ value times the bounding sphere of the start node. If false, meters is used.	Boolean	Value of type ‘Boolean’	Yes
UseRelativeOffset	Decides whether to use relative distances for the offset distance. This means that the offset distance will be computed as the provided ‘Offset’ value times the bounding sphere of the start node. If false, meters is used.	Boolean	Value of type ‘Boolean’	Yes
Width	The width of the arrow, in meters.	Double	Greater or equal to: 0	Yes

Inherited members from Renderable

Name	Documentation	Type	Description	Optional
DimInAtmosphere	Decides if the object should be dimmed (i.e. faded out) when the camera is in the sunny part of an atmosphere.	Boolean	Value of type ‘Boolean’	Yes
Enabled	Determines whether this object will be visible or not.	Boolean	Value of type ‘Boolean’	Yes
Opacity	This value determines the opacity of this renderable. A value of 0 means completely transparent	Double	In range: ( 0,1 )	Yes
RenderBinMode	A value that specifies if the renderable should be rendered in the Background, Opaque, Pre-/PostDeferredTransparency, Overlay, or Sticker rendering step.	String	In list { Background, Opaque, PreDeferredTransparent, PostDeferredTransparent, Overlay }	Yes
Tag	A single tag or a list of tags that this renderable will respond to when setting properties	Table, or String	Value of type ‘Table’, or Value of type ‘String’	Yes
Type	The type of the renderable.	String	Value of type ‘String’	Yes

Asset Examples

Basic

This example shows an arrow pointing from one scene graph node in the direction of another. Here, it points from Earth to Mars. Note that the arrows are generated as objects in 3D space and need to have a size that is suitable for the scene graph nodes they refer to. Here it is set based on the size of the Earth.

local earth = asset.require("scene/solarsystem/planets/earth/earth")
local mars = asset.require("scene/solarsystem/planets/mars/mars")

local Node = {
  Identifier = "RenderableNodeArrow_Example",
  -- Parent to the start node, so that when we focus on the arrow this is where we end up
  Parent = earth.Earth.Identifier,
  Renderable = {
    Type = "RenderableNodeArrow",
    StartNode = earth.Earth.Identifier,
    EndNode = mars.Mars.Identifier,
    -- How far away from the start node should the arrow start (meters)
    Offset = 2 * 6371000.0,
    -- How long should the arrow be (meters)
    Length = 5 * 6371000.0,
    -- How wide should the arrow be (meters)
    Width = 900000.0
  },
  GUI = {
    Name = "RenderableNodeArrow - Basic",
    Path = "/Examples"
  }
}

asset.onInitialize(function()
  openspace.addSceneGraphNode(Node)
end)

asset.onDeinitialize(function()
  openspace.removeSceneGraphNode(Node)
end)

Relative Units for Offset and Length

This example shows an arrow pointing from one scene graph node in the direction of another, but where the size is specified using relative values (based on the bounding sphere of the start node). Here it points from Earth to the Moon. Note that the arrows are generated as objects in 3D space and need to have a size that is suitable for the scene graph nodes they refer to. Here it is set based on the size of the start node, i.e. Earth.

local earth = asset.require("scene/solarsystem/planets/earth/earth")
local moon = asset.require("scene/solarsystem/planets/earth/moon/moon")

local Node = {
  Identifier = "RenderableNodeArrow_Example_Relative",
  -- Parent to the start node, so that when we focus on the arrow this is where we end up
  Parent = earth.Earth.Identifier,
  Renderable = {
    Type = "RenderableNodeArrow",
    StartNode = earth.Earth.Identifier,
    EndNode = moon.Moon.Identifier,
    -- Use relative values for offset and length
    UseRelativeOffset = true,
    UseRelativeLength = true,
    -- Specify relative values (times the size of Earth, in this case)
    Offset = 2.0,
    Length = 5.0,
    -- Width is in meters
    Width = 900000.0
  },
  GUI = {
    Name = "RenderableNodeArrow - Relative Units",
    Path = "/Examples"
  }
}

asset.onInitialize(function()
  openspace.addSceneGraphNode(Node)
end)

asset.onDeinitialize(function()
  openspace.removeSceneGraphNode(Node)
end)

Custom Appearance (Colored & Inverted)

This example shows an arrow pointing from one scene graph node in the direction of another. Here, it is created with the Solar System barycenter as start node and Earth as end node, but the arrow direction is inverted so that it points towards the Solar System barycenter. Some appearance related properties are also changed to customize the look of the arrow, but default values are used for its size.

local earth = asset.require("scene/solarsystem/planets/earth/earth")
local sunTransforms = asset.require("scene/solarsystem/sun/transforms")

local Node = {
  Identifier = "RenderableNodeArrow_Example_Appearance",
  -- Parent to the start node, so that when we focus on the arrow this is where we end up
  Parent = sunTransforms.SolarSystemBarycenter.Identifier,
  Renderable = {
    Type = "RenderableNodeArrow",
    StartNode = sunTransforms.SolarSystemBarycenter.Identifier,
    EndNode = earth.Earth.Identifier,
    -- Point to start node instead of end node
    Invert = true,
    -- Give the arrow a custom color (here a dark red)
    Color = { 0.5, 0.0, 0.0 },
    -- Set the arrow head size so that it takes up a quarter (25%) of the full length of
    -- the arrow
    ArrowHeadSize = 0.25,
    -- Set the arrow head width. A value of 1 makes it as wide as the body of the arrow
    ArrowHeadWidthFactor = 1.0
  },
  GUI = {
    Name = "RenderableNodeArrow - Custom Appearance (Colored & Inverted)",
    Path = "/Examples"
  }
}

asset.onInitialize(function()
  openspace.addSceneGraphNode(Node)
end)

asset.onDeinitialize(function()
  openspace.removeSceneGraphNode(Node)
end)