Voronoi By Steering Geometry

With this tool you can use a reference object to control the fragmentation process and create nearly endless variations. The interface is subdivided into three sections.

The mode of operation is easy: you only have to select the object you want to break apart from the “Nodes” panel, viewport or “Relationship Editor”. Then you call the “Voronoi By Steering Geometry” tool and add the desired object. The steering object will not be fragmented in that case, because its only purpose is to determine where you want to create zones with higher or lower concentrations of pieces – it can be seen as a reference or template.

Voronoi

Here, the basic settings are made. The parameters and options are exactly the same as under “Fracture Uniform”

Rough number of pieces

Here you can specify how many chunks you finally want to create. The resulting number of fragments is – at least in many cases – not exactly the entered value, but normally it is very close to it.

Seed

If you want to avoid the same distribution of fragments for equally shaped objects, or do not like the current pattern, please enter a different "Seed" value.

Global pattern

This option only works with a MultiBody. When “Global pattern” is deactivated, RealFlow creates an individual distribution of pieces for each object of the MultiBody based on the steering geometry. When “Global pattern” is active, the tool sees the node selection as one object and you will see a propagating pattern.

For more information please visit the introduction to RealFlow's Voronoi Tools. There you will find a detailed explanation.

Steering geometry

This is the place to adjust the properties of the reference object, which will be used for the fragmentation process to create zones of higher and lower density. You can use any available polygon object.

Steering geometry

To use an object, click on the “...” button and pick an item from the appearing list. It will then be shown in the input field. Alternatively, it is also possible to write the name of an existing object directly into the field. Please note that the name in the field must exactly match the appropriate node's name, including upper and lower cases, e.g. “Sphere01” ↔ “Sphere01” etc. If the object does not exist, the fragmentation process will not be started. The chosen object is used to indicate the zone with the highest concentration of pieces.

Steering resolution

For the fragmentation process, the steering objects are translated into a grid with cells and this parameter defines the resolution of the grid. Higher values create a result that represents the shape of the steering geometry much better.

Highest concentration

The drop-down menu provides four methods to control the distribution of the fragments. According to the selected mode, the Voronoi cells are more concentrated either inside, outside, along the boundary or out of the boundary – always referred to the steering geometry.

Lowest/Highest concentration rate

When you choose a steering object and a “Highest concentration” mode, the workspace is subdivided into two zones. With “Inside”, for example, you want to create a higher a number of pieces in areas which are located inside the steering object. This value determines the ratio of the number of fragments in both areas. An example:

As said before, there are two areas – inside and outside. Let’s say you want to create 100 pieces inside the zone with the highest concentration per fragment in the outer area (the zone of lowest concentration. In this case, the “Lowest/highest concentration rate” is calculated as:

1 / 100 = 0.01

With a value of 0.001, the ratio is 1: 1000 objects. You will also see that the transition between the areas with highest and lowest concentration becomes sharper with smaller rates.

Transition length

When fragments are distributed over a given area with the help of a reference object, you will get zones of higher and lower density. This parameter determines how the transition between these zones will finally look. With small values, there is a more or less sudden change between the low- and high-density zones. Higher values create smoother distribution. Please note that this value is given in meters: with a value of 3, the transition between zones with the highest and lowest concentration of pieces will be gradually changed over 3 metres.

Extrusion effect

With this option enabled, all seeds will be distributed over an automatically created, virtual 2D plane. The result is an effect that is similar to the look of a jigsaw puzzle: there, the pieces are simply cut out and are not arranged in “layers” or stacks. “Extrusion effect” is useful if you want to punch a hole into a wall or create the effect of a thin breaking pane of glass.

Channels

Split into internal/external (automatic criterion)

When you work with reference objects, the pieces are created in two zones with the highest and lowest concentration of pieces. With this option it is possible to separate these fragments and store them in two individual “MultiBody” nodes.