Particle Transparency over Time

How can I animate the transparency of particles as they age. I’d like to use ChromaKey in network. I can manipulate the keying of the sprite (TVG drawings that will be used as a Sprite) as long as that sprite is plugged straight into the final Composite. As soon as I plug the sprite back into the Emitter, the keying values go away. It’s going to be a drag if I have to render the sprite out as a prebuild.

There’s a way to do this.

  1. Open you Sprite Emitter module and navigate to the Rendering tab
  2. In the “Colouring” area, change the Colouring Strategy to “Apply Opacity Based on Age”
  3. Create a bezier function on the alpha value.
  4. Open your function editor and set a keyframe at frame 1 and frame 10.
  5. Set keyframe 1 value to 255 and keyframe 10 value at 0.
  6. Playback your scene, you will see that every particle will be visible at birth and will get transparent at frame 10.

You can drag the end keyframe in the timeline so you can control when you want the alpha to be at 0.

I hope this is clear enough.


Francois