Access particles lifetime in shader

So i’m working on a dissolve effect for better blood spill and splash effects. Is the particle lifetime already accessible in the shader or do i need to implement it ? if so is there a “unused float” somewhere in the particle’s vertex element structure that i could use without heavily modifying the ParticleEmitter or do i need to extend the current vertex data structure ?

Since ParticleEmitter is literally just BillboardSet with some automatic management, no, it doesn’t have an easy way to get TTL in shader. Your best bet would be to utilize bilboard color… or rewrite both ParticleEmitter and BillboardSet to pass some extra stuff to shader.