Blueprint basics

Blueprint is a scripting language using nodes. It comes from Unreal Engine and is derivated from C++ coding language. This lesson is a beginner introduction to Blueprint. However, we advise you to read the documentation of Unreal Engine if you need advanced explanations.

Blueprint interface

To open an Odyssey Brush, you must double click on its icon, either from the Content Drawer, or from the Brush Selector. If you open a new Odyssey Brush, you will get this window:

../_images/odysseybrush-intro-basics-blueprint.png

The panel on the left, “My Blueprint” will stock all the custom elements you might need to create, such as variables, functions or macros. The panel on the right, “Details” displays details on the a node or a custom element that is selected in the interface.

Add a node

You can open nodes directly in the Blueprint grid with a right click:

../_images/odysseybrush-intro-basics-opennode.png

You can also go to the “Window” menu and enable “Palette” to keep nodes aside. Nodes specific to Odyssey Brushes are into “Odyssey” categories.

../_images/odysseybrush-intro-basics-opennode2.png

Node connection

Connecting nodes is really easy! Nodes are made of input values (on the left side) and output values (on the right side). Nodes must be connected to each other. To do so, hold the click on an input or output to create a string and plug it in the right socket.

../_images/odysseybrush-blueprint-connect-nodes.gif

If you change your mind, you can use the shortcut Alt to cut an existing string.

Comment

You can organise nodes thanks to comments. To add comments:

  • Select several nodes

  • Make a right click

  • In the drop-down menu, select “Create Comment from Selection”

../_images/odysseybrush-intro-basics-comment-details.png

In the panel “Details”, you will be able to change settings like:

  • The name of the Comment Text (give an explicit title)

  • The color of the Comment

  • The size of the font

  • A bubble with additional explanations and its color

  • The Move Mode of the Comment

For instance, the default mode “Group Movement” allows you to move all nodes into the commented section.

../_images/odysseybrush-blueprint-group-move.gif

Compile & save

Compiling your Blueprint is mandatory to test your Odyssey Brush.

../_images/odysseybrush-intro-basics-compile.png

Your Blueprint needs to be compiled.

../_images/odysseybrush-intro-basics-compiled.png

Your Blueprint has been compiled and works well.

../_images/odysseybrush-intro-basics-error.png

Your Blueprint has some errors to fix. For more information, see Compiler Result panel.

../_images/odysseybrush-intro-basics-error-compiler.png ../_images/odysseybrush-intro-basics-save.png

Click here to save the changes you brought to your Bluperint.

Be careful : compiling won’t save and saving won’t compile. These are two different tasks.

Structure of an Odyssey Brush

And Odyssey Brush is usually made of this classical structure:

  1. Event: Node that triggers the stroke on the canvas

  2. Stamp: Node that creates the stamp for the stroke

  3. Variable: Custom elements with colors or image to be used in the Stamp

  4. Nodes: All nodes that configure the stroke: size, blend, rotation, connection with the tablet, etc.

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