Snowflake with the Duplicate Layer¶
This tutorial explain a simple example of the use of the `Duplicate Layer <Duplicate_Layer>`__, to create a snowflake.
First branch of the snowflake¶
Spline tool, and in the tools options, make sure that
Create Region is checked. (If you use the
Create Polygon Layer or
Create Region, as you
Draw the branch in the upper middle part of your image. Once it’s drawn,
select the newly created layer (I will refer to it as the “Branch
layer”) and make sure that the bottom of the branch is more or less at
the same place as the green dot showing the center of the image. You can
move your branch by selecting all the points
Ctrl|A and using the
Adding the Rotate and Duplicate Layers¶
To make a whole 6-branches snowflake, we need to make several copies of the branch, and rotate them.
First, we need a Rotation layer. Right click on the
image and select
|New Layer|Transform|Rotate. You should now have
a Rotate Layer on top of the Branch layer.
Then, we’ll use the Duplicate Layer. Right click on the image and select
So far, no change is visible on our image, it’s normal :).
In the Layers Panel, make sure that the layers are in the following order : Duplicate on top, Rotate in the middle, and the “Branch” layer on the bottom.
Connecting everything together¶
Select the Duplicate layer and look at the Parameters
Panel. There’s an
Index value that is
automatically exported. Its name is
Index 1. (It looks like
Index (Index 1) in the panel).
This value is made of 3 subparameters :
Those parameters tells how many times an object is duplicated.
We need 6 branches so set the
To parameter to 6 (keep
Step to 1).
Now move to the Library Panel, and select our
Index 1 value. (Unfold the
ValueBase Node if necessary).
In order to have 6 rotated branches, we need to link the duplication and the rotation together.
Select the Rotate layer, and go back to the Parameters panel.
The Rotate layer has just 2 parameters:
important one here is
Amount, it tells the angle of the rotation.
Right click on
Amount and select
<Convert> → Scale.
Now Amount is made of 2 subparameters,
Link (an angle) and
Scalar (a real), the whole rotation being equal to Link * Scalar.
Link subparameter to 60 (that’s the angle between the
Right click on the
Scalar parameter and select
Connect. It will
connect the previously selected
Index 1 value (in the Library panel)
to the Scalar parameter.
How it looks after the connection:
You should now have a complete snowflake, yay! (maybe you will need to adjust Rotate Layer’s Origin_Parameter)
We linked the “Scalar” value of the rotation to the duplicate layer:
Thanks to the Duplicate, the Scalar parameter was set to values between 1 and 6 (From and To), by steps of 1 - instead of being set to a single value.
So we had 5 rotations in addition to the original branche : One of 60° (Scalar * Link = 1 * 60°), another of 120° ( 2 * 60°), another of 180°, etc. And all of these rotations were displayed together.
You can think of the Duplicate Layer as something allowing you to have a list of values, that you can link to a (real) parameter in the same way you could link a single value to a parameter.