Emitter basic tutorial

Creating a snowfall visual effect

This beginner tutorial demonstrates how to create a snowfall effect with 1 emitter, using the VFX Editor in the Hology Engine. By following these steps, you’ll learn how emitters, behaviors, and properties work together to produce dynamic particle effects.

Create a new visual effect

1. In the asset browser, select → Add New → select Visual Effect.

1. Name the new effect, for example, “Snowy” → click Create.

2. The VFX Editor will open automatically.

Configure the emitter

1. Select Add emitter on the upper right hand corner of the VFX editor.

1. Click on the created emitter to open the emitter edit window.

2. Set the Type to Continuous to ensure the snow continuously spawns.

3. Under Count, enter 14 to increase the number of active particles.

4. Change the Spawn Time to 0.6 seconds to control how frequently particles appear.

5. Find the Initializers category → In the Lifetime property, enter a duration time, for example, 6, so snowflakes remain visible longer.

Add randomized particle direction

1. Initializers category → Click the + button to add a new emitter property.

2. Select Random Direction.

1. Adjust the Speed value to give snowflakes varying movement directions. For example, change the Speed value to 3.85. You should now see particles drifting in different directions within the scene view.

Define the particle spawn area

1. Initializers category → Click the + button again and choose Position Box. This defines a 3D region where particles can appear.

2. Set the Dimensions to: X: 50, Y: 0.3, Z: 50 This ensures snowfall covers a wide area.

Adjust particle scale

1. Initializers category → Click + button → Select Scale. Set Scale to 0.5. Smaller particles create a lighter, more realistic snowfall effect.

Add random drift behavior

1. Find the Behaviours category → click + button → select Random Drift (highlighted in yellow in the picture below)

1. Set Drift values to 0.2, 0.2, 0.2. Random Drift applies small, subtle motion variations, simulating natural turbulence in falling snow. You can experiment with these values for different looks.

Apply gravity

1. In the Behaviours Category → click + button → select Gravity.

2. Reduce the gravity force from 8 (default) to 0.1. A smaller gravity value slows the fall speed, producing a gentle snowfall rather than a heavy drop.

Add fade out with opacity

1. In the Behaviours category → click + button → select Change Opacity.

2. Set the Start Opacity (A) to 0 → then set End Opacity (B) to 1. This creates a fade-out effect as snowflakes reach the ground.

Apply linear damping

1. In the Behaviours category → click the + button → select Linear Damping.

2. Set Factor value to 2. This introduces air resistance, causing snowflakes to gradually slow down as they fall, enhancing realism.

Save and place in the scene

1. When satisfied, click Save (or press Ctrl and S key at the same time), and close the VFX editor.

1. Click on the VFX and hold → drag and drop the Snowy VFX from the asset browser into your scene.

1. Move the effect slightly higher in the scene hierarchy so the snow appears to fall from above.

You’ve now created your first visual effect in the Hology Engine!