The Concept Behind MITK Properties

Properties belong to a datanode and contain information relevant to the handling of the node by MITK. They provide a place to store additional information which is not part of the actual data, and as such have no reason to be contained within the data/file itself, but might be needed for such things as rendering (e.g. transfer functions) or interaction (e.g. the name of the node).

Properties can be read and set:

//1: Read a property
mitk::Property::Pointer readProperty = node->GetProperty("color"); //read the property "color" from the data node
mitk::ColorProperty::Pointer colorProperty = dynamic_cast<mitk::ColorProperty*>(readProperty); //cast this property to the subtype ColorProperty
 
//2: Write a property
mitk::BoolProperty::Pointer newProperty = mitk::BoolProperty::New( true ); //create a new property, in this case a boolean property
node->SetProperty( "IsTensorVolume", newProperty ); //add this property to node with the key "IsTensorVolume"

Property Services

Property services enable you to extend the capabilities of the basic property system of MITK. Currently there are four property services, i.e., aliases, descriptions, extensions, and filters. All of them are briefly described in the following. More detailed information can be found in the corresponding API documentation, as all of the services are completely documented.

All property services are provided through the functionalities of the C++ Micro Services. Hence, you can use property services from all of your modules and plugins.

Property Aliases

You can add an alias to a certain property name which is displayed by the Property View instead of the genuine property name. A property name can have more than one alias in which case the property is displayed multiple times in the Properties View. In addition, aliases can be easily restricted to certain data node types.

Property aliases are provided through the service interface mitk::IPropertyAliases.

Property Descriptions

The Property View will display a description of the currently selected property at its bottom if the property has an associated description. Descriptions are parsed and displayed as rich text.

Property descriptions are provided through the service interface mitk::IPropertyDescriptions.

Property Extensions

Property extensions are a very generic approach to attach meta data to properties. They have the sole requirement of inheriting from mitk::PropertyExtension. The Property View searches for known property extensions like mitk::IntPropertyExtension and mitk::FloatPropertyExtension to configure the editors of the properties, e.g., you can specify the valid range for a numeric property.

Property extensions are provided through the service interface mitk::IPropertyExtensions.

Property Filters

Property filters are a rather powerful tool to filter shown properties by the Property View. There is a single global filter and the possibility to add filters on top of it for specific data node types. Filters consist of blacklist entries and whitelist entries, i.e., blacklisted entries are filtered out and whitelisted entries are the only properties which remain after filtering. If both lists contain entries only whitelisted entries are displayed that are not blacklisted.

Property filters are provided through the service interface mitk::IPropertyFilters.

A List Of Module Independent Properties

This section lists most of the known properties in MITK according to where they are used. Not every node needs each (or even close to) of these properties.

File Management

path - The physical path the file was loaded from
name - The node name in the datamanager
selected - Whether the node is selected in the datamanager

Generic Rendering Properties

color - Color the surface, grey value image, whatever should be rendered in (default is usually white). There is a special mitk::ColorProperty and you can use the Getter/Setter methods to access it. The color is defined with three values (RGB) in the range between 0.0 and 1.0.
Remarks
If you are inside a mapper you can use the following code to access the color:
float rgb[3]={1.0f, 1.0f, 1.0f};

GetColor( rgb, BaseRenderer );

(The BaseRenderer is usually known inside a mapper).

Warning
This property will not affect images if you set the property "LookupTable". In that case a user-defined lookuptable will be used.
in plane resample extent by geometry - Toggles: Resampling grid corresponds to the current world geometry. This means that the spacing of the output 2D image depends on the currently selected world geometry, and not on the image itself.
Resampling grid corresponds to the input geometry. This means that the spacing of the output 2D image is directly derived from the associated input image, regardless of the currently selected world geometry.
layer - Controls which image is considered "on top" of another. In the case that two should inhabit the same space, the higher layer occludes lower layer. So far it works for images and pointsets. The layer property applies only for similar datatypes. Pointsets are always rendered in front of images and the layer will not have any effect.
levelwindow - In general, grayscale images contain values between 0 and 255. Therefore, the default window boundaries are set respectively. For displaying the image within a certain range, ie. 50 - 200, this property can be used to adjust the minimum and maximum boundary.
LookupTable - This property contains a user defined lookuptable, which can be used to map scalar values to color values. Example: If an image contains a value of 128, in the resulting image the passed lookuptable could map this value to red (255, 0, 0).

Warning
If you set the "LookupTable" property the "color" property will not longer affect your image.

Example for setting up a lookuptable in MITK:
#include <vtkSmartPointer.h>

#include <vtkLookupTable.h>

#include <mitkLookupTable.h>

#include <mitkLookupTableProperty.h>

[...]

vtkSmartPointer<vtkLookupTable> vtkLUT = vtkSmartPointer<vtkLookupTable>::New();

vtkLUT->SetRange(100,200); //define your table here

vtkLUT->Build();

//pass the table to MITK

mitk::LookupTable::Pointer mitkLookupTable = mitk::LookupTable::New();

mitkLookupTable->SetVtkLookupTable(vtkLUT);

mitk::LookupTableProperty::Pointer LookupTableProp = mitk::LookupTableProperty::New( mitkLookupTable );

result->SetProperty( "LookupTable", LookupTableProp );

result->Update();
opacity - Alpha (or transparency) value of the node/image/surface etc.. The range of the opacity is between 0.0 and 1.0.

Remarks
If you are inside a mapper you can use the following code to access the opacity:
float opacity=1.0f;

GetOpacity( opacity, BaseRenderer );

(The BaseRenderer is usually known inside a mapper).
reslice interpolation - This property takes effect in swivel mode or crosshair rotation only. The interpolation modes "Nearest", "Linear", and "Cubic" are available and effect the pixel outcome along the rotated plane.
texture interpolation - This property toggles interpolation of the texture. If enabled, edges between image pixels are blurred. If disabled, edges remain sharp.
visible - toggle node/image/surface being rendered at all

Surface Rendering Properties

back color - in 2D, color of the normals outside the surface
back normal length (px) - in 2D, length of the normals in pixels (When decreasing it the color using the front color is shorter?)
color mode - (From VTK) Control how the scalar data is mapped to colors. By default (ColorModeToDefault), unsigned char scalars are treated as colors, and NOT mapped through the lookup table, while everything else is. Setting ColorModeToMapScalars means that all scalar data will be mapped through the lookup table.
draw normals 2d - in 2D, toggles the presence of normals
front color - in 2D, color of the normals inside the surface
front normal length (px) - in 2D, length of the normals in pixels (When decreasing it the color using the back color is shorter?)
invert normals - in 2D, switch front/back normals
line width - in 2D, controls the thickness of the line where the surface intersects the plane (and normals)
material.ambientCoefficient - in 3D ambient lighting
material.diffuseCoefficient - in 3D scattering of light
material.interpolation - Choose which interpolation algorithm to use for surface construction
material.representation - Choose the representation to draw the mesh in (Surface, Wireframe, Point Cloud)
material.specularCoefficient - in-/decrease non-scattered reflection
material.specularPower - control percentage of non-scattered reflection
material.wireframeLineWidth - width of the wires if wireframe representation is
scalar mode - (From VTK) Control how the filter works with scalar point data and cell attribute data. By default (ScalarModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (ScalarModeToUsePointData) or cell data (ScalarModeToUseCellData). You can also choose to get the scalars from an array in point field data (ScalarModeToUsePointFieldData) or cell field data (ScalarModeToUseCellFieldData). If scalars are coming from a field data array, you must call SelectColorArray before you call GetColors. When ScalarMode is set to use Field Data (ScalarModeToFieldData), you must call SelectColorArray to choose the field data array to be used to color cells. In this mode, if the poly data has triangle strips, the field data is treated as the celldata for each mini-cell formed by a triangle in the strip rather than the entire strip.
scalar visibility - (From VTK) Turn on/off flag to control whether scalar data is used to color objects.
selected - whether the node is selected
shader - which shader to use for surface rendering, currently the options are "fixed" and "mitkShaderLightning"

Volume Rendering Properties

TransferFunction - contains transfer function for use in coloring image
volumerendering - Should the volume be rendered or not
volumerendering.ambient - same as cpu with gpu
volumerendering.diffuse - same as cpu with gpu
volumerendering.specular - same as cpu with gpu
volumerendering.specular.power - same as cpu with gpu

Point Set Properties

close contour - Toggles whether the first and the last point of a contour (connecting pieces between following points of a pointset) are connected.
contourcolor - Determines the color of the contour (connecting pieces between following points of a pointset). Visible only if "show contour" is active.
contoursize - Represents the diameter of the contour (which is kind of a tube between the following points of a pointset). Visible only if "show contour" is active.
distance decimal digits - Sets the number of decimal places for the euclidean point to point distance which can be displayed by activating "show distances".
point 2D size - The positions of points in the 2D view are represented by crosses. "point 2D size" determines the size of this crosses.
point line width - The positions of points in the 2D view are represented by crosses. "point line width" determines the thickness of this crosses.
pointsize - The positions of points in the 3D view are represented by spheres. "pointsize" determines the diameter (size) of this spheres.
selectedcolor - Sets the color for selected points from a pointset.
show angles - If "show contour" is active the angles between two contour parts can be shown.
show contour - Connects following points of a pointset by drawing connecting pieces between this points.
show distance lines - Shows all angles and lines of the contour (in 2D views) even if they are not on the view's current slice.
show distances - Draws lines between following points (in 2D views) and displays the euclidean distance between this points.
show points - Toggles if the points are visible or not in the view.
updateDataOnRender - If "true" the pointset is updated before rendering. If the pointset is part of a filter pipeline this also causes an update to the pipeline which sometimes may be not desired so it can be switched of by setting it to false.

Geometry2D Properties

draw edges - Determines if tubes should be drawn around the edges of the 2D plane. Default is true.

Information on properties not in this list can be found in the appropriate module.

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