Blocks

Blocks are Nodes that define the behavior of a Context. You can create and reorder Blocks within a Context and, when Unity plays a visual effect, Blocks execute from top to bottom.

You can use Blocks for many purposes, from simple value storage (for example, a random Color) to high-level complex operations such as Noise Turbulence, Forces, or Collisions.

Adding Blocks

To add a Block to a Context, either:

• Right click the Context and select Create Block from the context menu.
• With the cursor above a Context, press the spacebar.

Note: Unity places the Block that you create at the closest position to the cursor. Use this behavior to place Blocks in the correct position.

Manipulating Blocks

Blocks are essentially Nodes that have a different workflow logic. Blocks are always stacked within a container, called a Context and their workflow logic connects vertically without visible links.

• To move a Block, click the Block's header and drag it to another compatible Context.

• To reorder a Block, click the Block's header and drag it to a different position in the same Context.

• You can perform various actions on Blocks, such as cutting, copying, pasting, and duplicating. To do this:

  • Right-click on the Block and select the command from the context menu.

  • Select the Block and use the following keyboard shortcuts:

    • On Windows:

      • Copy: Ctrl+C.
      • Cut: Ctrl+X.
      • Paste: Ctrl+V.
      • Duplicate: Ctrl+D.

    • On macOS:

      • Copy: Cmd+C.
      • Cut: Cmd+X.
      • Paste: Cmd+V.
      • Duplicate: Cmd+D.

• To disable a Block, disable the checkbox to the left of the Block's header. This requires you to recompile the graph.

Configuring Blocks

To change the way that the Block looks and behaves, adjust the Block's Settings in the Node UI or the Inspector.

For example, if, in the Inspector, you change the Composition Settings of a Set Velocity Block from Overwrite to Blend, this changes the title of the Node to Blend Velocity and adds a Blend property to the Node UI.

Activation port

In addition to its property ports, a Block has a special port called the activation port. It is located on the top left of a Block, next to its name.

The activation port is linked to a boolean property and allows the user to control if a Block is active.

You can use the toggle next to the port to manually activate or deactivate a Block.

You can connect a graph logic to the activation port to accurately control under which conditions a Block is active per invocation. This allows you to implement different behaviors or states per particle within the same system.

Unity is able to determine if a Block is statically inactive. An inactive Block appears greyed out, and Unity removes it during compilation so it has zero runtime cost.

Note: Subgraph Blocks don't have activation ports. To emulate an activation port, you can expose a boolean exposed property from the subgraph, and connect the property to the activation ports of the subgraph's internal Blocks.