This is probably a very basic question but here we go.

I have a box which has animation on it at the object level. I have a separate object with a popnet in it. The popnet has a location emitter with some gravity and drag attached. The emitter is emitting in the X-axis.

The behaviour I want is for the emitter to emit along the X-axis of the animated box but I then want the particles to be free to be pulled down by the gravity i.e. I don't want the whole particle system to move with the animation of the box. The particle should shoot off along the vector the x-axis was pointing down on the frame that particular particle was emitted.

I can't figure out how to do this. Any help would be gratefully received. My mind's not quite in that Houdini place yet!

I have attached my not working at all file.

Please check attached project ,maybe this is your solution

Thanks Joker!

This is exactly what I was looking for. Really well commented too.

Thanks again for your help.

Your welcome my friend

If you used the Source from geometry in the Particles tool shelf, it would have created a net new object that object merges in the source geometry in world space and constructs the POP network in there.

This is the way I've been handling my emitters for years as it allows you to support object parenting and animation without issues. This is also how the shelf tool works.

If you select colliders as well from the Collision shelf tool, it too will correctly object merge in the colliders in to that new object then reference that object merge SOP in the POP network. Again avoiding any issues with object level transforms and animation.