Making hair particules track something ?

Hi, i got some hair particules in a sphere.

The visualization type is set to group and the group are some planes with trees images.

So I want these planes to track a camera, as the planes are flat i need the planes to always track the camera so they are always visible if the planes are rotated there would be a moment when they would not be visible as they are planes.

So i have tried to track the planes to the camera but i just cant get the effect i want.

Is this posible ?

here’s the blend file :

Use Particles with Billboard visualization, that is exactly made for your purpose.

Thanx, but billboard is oly available in emitter mode not in hair, and i dont see how to use a group if i use emiter, i need a group as i have many different trees.

Add a TrackTo constraint to the objects in your group and set the particles rotation to the objects tracking axis.