RenderablePointCloud

Inherits Renderable

A RenderablePointCloud can be used to render point-based datasets in 3D space, optionally including color mapping, a sprite texture and labels. There are several properties that affect the visuals of the points, such as settings for scaling, fading, sprite texture, color mapping and whether the colors of overlapping points should be blended additively or not.

The point size depends on a few different things:

• At the core, scaling is done based on an exponential value, the ‘ScaleExponent’. A relatively small change to this value will lead to a large change in size. When no exponent is set, one will be created based on the coordinates in the dataset. The points will be visible, but may be appeared as too large or small. One option is to not specify the exponent when loading the dataset for the the, first time, to make sure the points are visual, and then adapt the value interactively when OpenSpace is running until you find a value that you find suitable.

• There is also an option to limit the size of the points based on a given max size value.

• To easily change the visual size of the points, the multiplicative ‘ScaleFactor’ may be used. A value of 2 makes the points twice as large, visually, compared to 1.

See example files in data/assets/examples/pointcloud for some concrete examples of point clouds with different settings.

Members

Name	Documentation	Type	Description	Optional
Coloring	Settings related to the coloring of the points, such as a fixed color, color map, etc.	Table	Table parameters	Yes
DataMapping	A dictionary specifying details on how to load the dataset. Updating the data mapping will lead to a new cached version of the dataset	Table	DataMapping	Yes
DrawElements	Enables/Disables the drawing of the points	Boolean	Value of type ‘Boolean’	Yes
Fading	Settings related to fading based on camera distance. Can be used to either fade away or fade in the points when reaching a certain distance from the origin of the dataset	Table	Table parameters	Yes
File	The path to the data file that contains information about the point to be rendered. Can be either a CSV or SPECK file	File	Value of type ‘File’	Yes
Labels	The labels for the points. If no label file is provided, the labels will be created to match the points in the data file. For a CSV file, you should then specify which column is the ‘Name’ column in the data mapping. For SPECK files the labels are created from the comment at the end of each line	Table	LabelsComponent	Yes
RenderOption	Option wether the point billboards should face the camera or not. Used for non-linear display environments such as fisheye.	String	In list { Camera View Direction, Camera Position Normal }	Yes
SizeSettings	Settings related to the scale of the points, whether they should limit to a certain max size, etc.	Table	Table parameters	Yes
SkipFirstDataPoint	If true, skip the first data point in the loaded dataset	Boolean	Value of type ‘Boolean’	Yes
Texture	Settings related to the texturing of the points	Table	Table parameters	Yes
TransformationMatrix	Transformation matrix to be applied to the position of each object	Matrix4x4<double>	Value of type ‘Matrix4x4’	Yes
Unit	The unit used for all distances. Should match the unit of any distances/positions in the data files	String	In list { m, Km, pc, Kpc, Mpc, Gpc, Gly }	Yes
UseAdditiveBlending	If true (default), the color of points rendered on top of each other is blended additively, resulting in a brighter color where points overlap. If false, no such blending will take place and the color of the point will not be modified by blending. Note that this may lead to weird behaviors when the points are rendered with transparency.	Boolean	Value of type ‘Boolean’	Yes
UseCaching	If true (default), the loaded dataset will be cached so that it can be loaded faster at a later time. This does however mean that any updates to the values in the dataset will not lead to changes in the rendering without first removing the cached file. Set it to false to disable caching. This can be useful for example when working on importing a new dataset	Boolean	Value of type ‘Boolean’	Yes

Inherited members from Renderable

Name	Documentation	Type	Description	Optional
DimInAtmosphere	Enables/Disables if the object should be dimmed when the camera is in the sunny part of an atmosphere	Boolean	Value of type ‘Boolean’	Yes
Enabled	This setting 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	This value specifies if the renderable should be rendered in the Background,Opaque, Pre/PostDeferredTransparency, or Overlay 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	This tells the type of the renderable	String	Value of type ‘String’	Yes

Table parameters for Coloring

Settings related to the coloring of the points, such as a fixed color, color map, etc.

• Optional: Yes

Name	Documentation	Type	Description	Optional
ColorMapping	Settings related to the choice of color map, parameters, etc.	Table	ColorMappingComponent	Yes
EnableOutline	This setting determines if each point should have an outline or not. An outline is only applied when rendering as colored points (not when using textures).	Boolean	Value of type ‘Boolean’	Yes
FixedColor	This value is used to define the color of the points when no color map isused	Color3	Value of type ‘Color3’	Yes
OutlineColor	This value defines the color of the outline. Darker colors will be less visible if Additive Blending is enabled.	Vector3<double>	Value of type ‘Vector3’	Yes
OutlineWeight	This value defines the color of the outline. Darker colors will be less visible if Additive Blending is enabled.	Double	Value of type ‘Double’	Yes

Table parameters for Fading

Settings related to fading based on camera distance. Can be used to either fade away or fade in the points when reaching a certain distance from the origin of the dataset

• Optional: Yes

Name	Documentation	Type	Description	Optional
Enabled	Enables/disables the Fade-in effect based on camera distance. Automatically set to true if FadeInDistances are specified in the asset.	Boolean	Value of type ‘Boolean’	Yes
FadeInDistances	These values determine the initial and final distances from the origin of the dataset at which the points will start and end fading-in. The distances are specified in the same unit as the points, that is, the one provodied as the Unit, or meters. With normal fading the points are fully visible once the camera is outside this range and fully invisible when inside the range. With inverted fading the situation is the opposite: the points are visible inside hen closer than the min value of the range and invisible when further away.	Vector2<double>	Value of type ‘Vector2’	Yes
Invert	This property can be used the invert the fading so that the points are invisible when the camera is further away than the max fade distance and fully visible when it is closer than the min distance.	Boolean	Value of type ‘Boolean’	Yes

Table parameters for SizeSettings

Settings related to the scale of the points, whether they should limit to a certain max size, etc.

• Optional: Yes

Name	Documentation	Type	Description	Optional
EnableMaxSizeControl	If true, the Max Size property will be used as an upper limit for the size of the point. This reduces the size of the points when approaching them, so that they stick to a maximum visual size depending on the Max Size value.	Boolean	Value of type ‘Boolean’	Yes
MaxSize	This value controls the maximum allowed size for the points, when the max size control feature is enabled. This limits the visual size of the points based on the distance to the camera. The larger the value, the larger the points are allowed to become. In the background, the computations are made by limiting the size to a certain angle based on the field of view of the camera. So a value of 1 limits the point size to take up a maximum of one degree of the view space.	Double	Value of type ‘Double’	Yes
ScaleExponent	This value is used as in exponential scaling to set the absolute size of the point. In general, the larger distance the dataset covers, the larger this value should be. If not included, it is computed based on the maximum positional component of the data points. This is useful for showing the dataset at all, but you will likely want to change it to something that looks good.	Double	Value of type ‘Double’	Yes
ScaleFactor	This value is used as a multiplicative factor to adjust the size of the points, after the exponential scaling and any max size control effects. Simply just increases or decreases the visual size of the points.	Double	Value of type ‘Double’	Yes
SizeMapping	Settings related to scaling the points based on data	Table	SizeMappingComponent	Yes

Table parameters for Texture

Settings related to the texturing of the points

• Optional: Yes

Name	Documentation	Type	Description	Optional
AllowCompression	If true, the textures will be compressed to preserve graphics card memory. This is enabled per default, but may lead to visible artefacts for certain images, especially up close. Set this to false to disable any hardware compression of the textures, and represent each color channel with 8 bits.	Boolean	Value of type ‘Boolean’	Yes
Enabled	If true, use a provided sprite texture to render the point. If false, draw the points using the default point shape.	Boolean	Value of type ‘Boolean’	Yes
File	The path to the texture that should be used as the point sprite. Note that if multiple textures option is set in the asset, by providing a texture folder, this value will be ignored.	File	Value of type ‘File’	Yes
Folder	The folder where the textures are located when using multiple different textures to render the points. Setting this value means that multiple textures shall be used and any single sprite texture file is ignored. Note that the textures can be any format, but rendering efficiency will be best if using textures with the exact same resolution.	Directory	Value of type ‘Directory’	Yes
UseAlphaChannel	If true, include transparency information in the loaded textures, if there is any. If false, all loaded textures will be converted to RGB format. This setting can be used if you have textures with transparency, but do not need the transparency information. This may be the case when using additive blending, for example. Converting the files to RGB on load may then reduce the memory footprint and/or lead to some optimization in terms of rendering speed.	Boolean	Value of type ‘Boolean’	Yes

Asset Examples

Textured

This example creates a point cloud using a texture to render each point.

--
-- Note that other color related settings, like color mapping, can still be applied.
-- The color will then be multiplied with the texture color.

local Node = {
  Identifier = "RenderablePointCloud_Example_Textured",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Texture = {
      -- The path to the texture file. Here we use openspace.absPath so that we can use
      -- the ${DATA} token to get the path to a texture in the "OpenSpace/data" folder,
      -- but for a file at a relative location it would also work to use asset.resource,
      -- like for the data file above
      File = openspace.absPath("${DATA}/test3.jpg"),
    },
    -- Disable additive blending, so that points will be rendered with their actual color
    -- and overlapping points will be sorted by depth. This works best when the points
    -- have an opacity of 1
    UseAdditiveBlending = false
  },
  GUI = {
    Name = "Textured",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Point Size from Data

This example creates a point cloud where the size of the points is computed based on a column in the dataset

local Node = {
  Identifier = "RenderablePointCloud_Example_ScaledFromData",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      FixedColor = { 0.5, 0.5, 0.0 }
    },
    SizeSettings = {
      SizeMapping = {
        -- The options for the columns that the points can be scaled by. The first
        -- alternative in the list is chosen per default
        ParameterOptions = { "a", "b" },
        -- Specify which option we want to use for size mapping at start up. Here we
        -- use the last of the provided options rather than the first one, which is
        -- otherwise used by default
        Parameter = "b"
      },
      -- The size mapping can be used together with other scale parameters, such as a
      -- scale exponent or scale factor
      ScaleExponent = 4.8
    }
  },
  GUI = {
    Name = "Size from Data",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Draw Point Outline

This example creates a point cloud where the points have a colored outline with a given color and thickness (weight).

local Node = {
  Identifier = "RenderablePointCloud_Example_Outline",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      EnableOutline = true,
      OutlineColor = { 0.2, 0.2, 1.0 },
      OutlineWeight = 0.1
    },
    -- It might be desired to disable additive blending when using an outline
    UseAdditiveBlending = false
  },
  GUI = {
    Name = "Outlined",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Color Mapping

This example creates a point cloud where the color is set from a color map. All the data column in the dataset will be exposed in the user interface and can be used for color mapping during runtime. The range for the color mapping is set based on the min and max values in the dataset, for each column respoectively.

--
-- Note that the color map is loaded from another asset. This is a utility asset that
-- includes some common color maps for general usage.

local colormaps = asset.require("util/default_colormaps")

local Node = {
  Identifier = "RenderablePointCloud_Example_ColorMapped",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      ColorMapping = {
        File = colormaps.Uniform.Viridis
      }
    }
  },
  GUI = {
    Name = "Color Mapped",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Basic (Fixed Color and Size)

This example creates a point cloud with a fixed color and default size. All the points will have the same size.

local Node = {
  Identifier = "RenderablePointCloud_Example",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      FixedColor = { 0.0, 0.5, 0.0 }
    }
  },
  GUI = {
    Name = "Fixed Color and Size",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Point Size / Scaling

This example creates a point cloud where the size of the points is set by entering a a scale exponent. This makes it so that the points will be given a world-scale size of 10 to the power of the provided scale exponent.

local Node = {
  Identifier = "RenderablePointCloud_Example_Scaled",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      FixedColor = { 0.0, 0.0, 0.8 }
    },
    SizeSettings = {
      -- We set the exponent for the scale explicitly, to a value that
      -- gives the points a suitable size based on their world-space coordinates
      ScaleExponent = 6.5
    }
  },
  GUI = {
    Name = "Point Size / Scaling",
    Path = "/Examples/RenderablePointCloud",
    Description = "Point cloud with configured point size"
  }
}

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

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

Color Mapping with Pre-set Options and Missing Values

This example creates a point cloud where the color is set from a color map and the options for parameters to color by are pre-set to a limited number of options, including settings for which range to use. It also includes settings to render missing data values in gray.

--
-- Note that the color map is loaded from another asset. This is a utility asset that
-- includes some common color maps for general usage.

local colormaps = asset.require("util/default_colormaps")

local Node = {
  Identifier = "RenderablePointCloud_Example_ColorMapped_More",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      ColorMapping = {
        File = colormaps.Uniform.Viridis,
        -- Specify which parameters we want to show up in the user interface, as
        -- well as what range we want the color mapping to be done based on. If not
        -- included, all the columns in the data file would be exposed as options
        ParameterOptions = {
          { Key = "number_withNan" }, -- No range => compute min and max
          { Key = "normaldist_withMissing", Range = { -0.5, 0.5 } }
        },
        -- Also show missing data values in a specific color
        ShowMissingData = true,
        NoDataColor = { 0.5, 0.5, 0.5, 1.0 }
      }
    },
    SizeSettings = {
      ScaleExponent = 6.5
    }
  },
  GUI = {
    Name = "Color Mapped with Settings",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Limit Max Size

This example creates a point cloud where the size of the points is limited to a given max size. The color is set to a fixed value.

local Node = {
  Identifier = "RenderablePointCloud_Example_MaxSize",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Coloring = {
      FixedColor = { 0.0, 0.8, 0.8 }
    },
    -- Set the max size of the points. The larger the "MaxSize" value, the larger the
    -- points are allowed to get when moving the camera closer to them
    SizeSettings = {
      MaxSize = 0.7,
      EnableMaxSizeControl = true
    }
  },
  GUI = {
    Name = "Max Size",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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

Units

This example creates a point cloud where the positions are interpreted to be in another unit than meters (here kilometers).

local Node = {
  Identifier = "RenderablePointCloud_Example_Units",
  Renderable = {
    Type = "RenderablePointCloud",
    File = asset.resource("data/dummydata.csv"),
    Unit = "Km"
  },
  GUI = {
    Name = "Units",
    Path = "/Examples/RenderablePointCloud"
  }
}

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

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