This is a paid asset, but now you can download SpriteToParticles Free.
Detail this asset from Unity Store: Original Link
SpriteToParticles v2.1
SpriteToParticles is a script that use a Sprite component or Image component (UI) as a emitter for the Shuryken Particle System. It uses the sprite pixel position and/or color as emission source.
Examples of use would be:
– Effects for your sprite character or items.
– Enhancement of backgrounds.
– Bringing life to static images.
Details:
– Full source, fully commented
– 14 Demos with different examples of use
– Works on all platforms (read documentation to check performance)
Try it out:
StP for Sprites
StP for UI
Considerations:
– Read/Write options must be enabled in texture import settings (Texture Importer).
– Mobile doesn’t handle well much particles. Try keeping emission low.
– Some example scenes won’t be available for Unity 5.4.
Please read the documentation and script reference linked below before buying
Documentation
Scripts Doxygen Reference
Update 2.0
(+) Completely reworked system
(+) New Effectors post particle system’s emission
(+) New Inspector that helps configuration.
(+) New added precision between frames option.
(+) New Border emission option (for dynamic emission only atm).
(+) New contextual menu options for faster development.
(+) Added execute in edit mode. Now changes are visible in edit mode.
(+) Added more example scenes
(+) Bugs fixing and warnings removal.
Update 1.2.2
(+) Added Static Emission for UI
(+) Fixed Unity 5.5+ issues
(+) Fixed UI some shader compiling errors (A “reimport all” in the project might be needed to fix this)
Update 1.2
(+) Added support for UI
(+) Added 2 UI Demo Scenes
(+) Added a new non UI Demo Scene
(+) Added a few prefabs for faster development (to be used as blueprints)
Note: Sliced UI Images not supported at the moment.