# Scrawl-canvas v8 - Particles test 011

## Tracer entity: generation and functionality

Select filter

#### Test purpose

Be aware that applying a filter to a particle system can cause it to fail in interesting yet mysterious ways! In some browsers, the addition of a filter can also cause a significant degradation in canvas animation speeds

- Create a path-based Shape entity.
- Create a Tracer entity; set it to delta-animate along the Shape entity's path.
- Clone the tracer entity (twice), giving each a clone of the original's artefact, and its own 'stampAction' function.
- Add a selection of Filter objects to the demo; check that applying a filter to one of the Tracer entitys displays as expected.
- Make the Shape entity draggable; check that the Tracer entitys keep up with the Shape (though their history details will not update).

Touch test: should work as expected

Annotated code