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titleDeprecated since 0.14

This article is deprecated. The described features are no longer available in current releases.

titleVersion 0.13 RC1

This page is part of the SCCharts Editor 0.13 RC1 documentation. This page is still under construction. We are still in the process of creating the release candidate. Please excuse any missing or incomplete entry. We apologize for any inconvenience.

Visualize the Simulation State with an SVG Image

Table of Contents


The Data Pool View shows all variables present in the simulation. However it can be difficult for humans to interpret the state of a model when having only a load of numbers and variables. The former KIELER Environment Visualization (KEV) had been developed to display the simulation state in a more pleasant way. Therefore KEV loaded an SVG image and could manipulate it to reflect the state of the simulation.


Besides displaying the state of the simulation, KiVis is also able to interact with the simulation, e.g., when an element in the simulation is clicked. Thus buttons in the SVG image can be created to set variables in the simulation, or to step, stop, play and pause the simulation.

Creating an SVG Image

In this section the open-source vector graphics program Inkscape is used to illustrate how to create an SVG image that can be used with KiVis.


Finally, save the result as Inkscape-SVG (recommended) or Normal-SVG and name it Lights.svg.

Groups and Layers

SVG is an XML format. Elements can be grouped and layers can be created which forms a hierarchy. When working with groups and layers in Inkscape, it can be useful to work with the XML-Editor (Ctlr+Shift+X).

Flowed Text

In Inkscape it is possible to create a flowed text element, which is text that wraps its content inside a user defined area. However this is not a fully specified feature in SVG and thus not supported by many SVG viewers. For instance Gimp displays these elements as black box and Firefox does not display them at all.
KEV and the newer KiVis uses Apache Batik for SVG rendering, which also does not support flowed text. If you encounter issues with text object, try to convert them to simple text in Inkscape, via Text > Convert to normal text.

For more information see also the Inkscape FAQ for this topic:

Text Colors

Sadly the Batik SVG Renderer that is used in KIELER does not handle text colors as well as Inkscape does. When setting the fill color directly on a text element in Inkscape, it will not be displayed in the Simulation Visualization View. The text will be black.

However there is a simple workaround: Select the text objects that should be colored, group them (Ctrl + G), then set the fill color on this group. The child elements will inherit the color and (for whatever reason) this does also work in Batik.

Creating a Configuration File

The configuration depends on the model to be simulated. In the following a simple kivis file is shown for the example model below.


When writing a visualiation configuration, code completion can be used to show the available attributes of an animation. In the following the available animations are explained.

Animation Handler Base Class

The attributes of this class are also available for all other animation handlers and provide generic features.


Applies the animation to this element as well as all child elements recursively.

This might be useful, e.g., to set the opacity of an element and also in its children and their children.
However, in most cases this option is not required.

Color Animation

It is used to change the appearance of elements. The fill color, stroke color and with as well as opacity can be changed.

fillColorString, either a color name of predefined colors,
or a hexadecimal rgb color
Sets the fill color
fillOpacityFloat, ranges from 0 (fully transparent) to 1 (fully visible)Sets the opacity of the filling
strokeColorSame as fillColorSets the color of the outline / stroke
strokeOpacitySame as fillOpacitySets the opacity of the outline / stroke
opacitySame as fillOpacitySets the overall transparency

Text Animation

This animation can be used for text objects in the SVG to set the font and text.

textStringSets the text of the element
fontSizeIntegerSets the size of the text element
fontFamilyString, name of an installed font (e.g. "Arial Black" or "serif")Sets the font family

Move Animation

This animation changes the position of an SVG element.

xFloatThe x coordinate relative to the original position
yFloatThe y coordinate relative to the original position
absoluteBooleanDetermines if the given position is absolute or relative to the element's original position

Rotate Animation

This animation changes the rotation of elements.

angleIntegerThe angle in degrees that the object should be rotated
anchorXFloat, 0 to 1

Relative position inside the SVG element where the anchor point of the rotation will be.

0 is at the left side, 1 is at the right side. Default is 0.5, which is the middle.

anchorYFloat, 0 to 1

Relative position inside the SVG element where the anchor point of the rotation will be.

0 is at the top side, 1 is at the bottom side. Default is 0.5, which is the middle.

Walk Path Animation

This animation is used to position SVG elements on SVG paths. Therefore the start value of the path and the end value of the path have to be defined. The position is then interpolated linearly between start and end.


nameStringThe id of the path in the SVG image

The start position of the path.

When the position value is the same as the value of this attribute, the object will be position at the beginning of the path.


The end position of the path.

When the position value is the same as the value of this, the object will be position at the end of the path.


The length of the path.

Can be used instead the absolute end position. In this case the end position is calculated as
end = start+length


Used to set a fixed position on the path. Normally the position is taken from a variable in the simulation data pool, but it can also be set to a fixed value with this attribute.

The value should be between start and end of the path

autoOrientationBoolean, true / falseDetermines if the object should also align its rotation to the path

When autoOrientation is true, this offset in degrees is added to the calculated rotation on the path.

For example if the element is facing with in the wrong direction when it is walking the path, an offset of 180 can be used to turn it.

anglesee rotate animationsee rotate animation
anchorXsee rotate animation

see rotate animation

anchorYsee rotate animationsee rotate animation

Attribute Values

Attributes can be set to a single constant value, a single variable in the simulation or using a more complex mapping from variable values to attribute values as shown in the example below.


Code Block
image: "Lights.svg"

animate theRect {
  apply color using showLight {
    stroke-width: value                          // Set the attribute to the current value of the variable
    stroke-color: 0 is "red", others is "orange" // Define a target value for all other cases
    opacity: 0-1 is value, others is 0.5         // More complex example that uses both keywords

Interaction with the Simulation

It is also possible to interact with the visualization. For the image that has been created above, a simple interaction could be configured as follows:


The interaction that is setup in this example is a click listener for theRect. If the element with this id is clicked, the variable showLight will be set to 1 and the simulation will perform a macro tick. However this is only done when the condition holds. Thus the simulation will not be stepped, if the showLight variable already has a value of 1.

Color Functions

There are also pre-defined functions to interact with the visualization environment. In the following example the variables color, a, r, g and b are set to the corresponding color values of the pixel on position x and y in the svg image. The pixel position is determined by the document size of the svg, which can be defined for example in Inkscape (File > Document Properties).

Code Block
image: "image.svg"

// Get the color of the pixel at position (x, y)
perform {
  color = getColor(x, y)
  a = getAlpha(x, y)
  r = getRed(x, y)
  g = getGreen(x, y)
  b = getBlue(x, y)

// Illustrate the position by moving an svg element there
animate theDot {
  apply move {
    x: x
    y: y
    absolute: true

Example Model

Create an empty SCChart and fill it with the following content: