How to make particles emit from certain parts of a 3D object? I made a spaceship with animation and I want the particles to come out from only the thrusters but it's coming out from all over the spaceship!
Use Vertex Groups.

In edit mode
Use Vertex Groups in the Particle System Settings ... Sub Panel Vertex Groups.


In [edit mode] a vertex group was created 
The same group was used in the Particles System Panel ...  Density.
Quick Tutorial https://www.youtube.com/watch?v=yzRS2cCiBnc