I posted an earlier question about a particle system not showing up based on the first minute of https://www.youtube.com/watch?v=Wv23dh6d3oE.
The particles fall from the plane in the above but for me the particles don't fall on the render preview (press Z + 8).
I made the particle parents appear Render > Render As to halo as this
I also set Unborn on under Extra. Why do I have do I have to do full render to see the particles fall ?