Usage Explanation
This article explains how to set up fluid effects and describes various effects included in the sample project.
As a prerequisite, please download the sample project from this page. If you wish to integrate it into your own project, download only the scripts and add them to your project.
Adding Nodes
→ Click on FluidSimulationController.
Perform basic settings here.
Enabling debug_draw_canvas will visualize the fluid display area in the editor, so we recommend keeping this enabled during development.
Next, add a FluidBlushNode.
This creates a basic fluid brush on the screen.
By default, the brush is a circle that follows the mouse.
Let’s modify this to create a brush that applies ink along the shape of an arbitrary sprite.
Create a new brush and a Sprite2D.
Set an image on the Sprite2D, assign NodeCapture to the BrushShape of the created brush, and specify the previously created Sprite2D in the Emit Target Path.
This creates a brush that uses a sprite.
When NodeCapture is assigned to BrushShape, it uses the position and rotation of the specified node as-is. Therefore, to move the newly created Sprite2D brush, you must move the Sprite2D itself.
Next, let’s apply effects to the brush using an EffectNode.
Add a new Sprite2D and name it ForceSprite (the name can be anything as long as it works).
Click on the texture, select NoiseTexture2D, choose ColorLamp and Noise, set the gradient and noise texture, then hide the sprite.
Now, add a new FluidEffectNode.
In the added FluidEffectNode, set Strength to 1, set ForceMode to Texture, and assign the previously created ForceSprite to the Texture field.
Set Strength to around 100, click on Gradation, and create a GradationTexture2D.
With this setup, press F6 to run the scene.
Force is applied in the shape of the noise texture, giving the brush an irregular wobbling effect.
This article has explained the basic brush creation process.
In future articles, we will explain various features and effects.