So I'm doing the Ari Danesh Next Steps tutorial ( M10 ),

In this tutorial he is basically showing different configurations possible between point, particle, metaball and force “nodes”.

To save time after having gone through one example of laying down each node, he starts to refer to a file that is available with the video that can be downloaded.

So I downloaded the file and simply turn on and off the relevant “geo” objects for each object ( that has the point, particle, etc. nodes within them ) that relates to the part of the tutorial he discusses.

Problem is, although I didn't build the objects he refers too, he does go through most of each node showing the settings of each node and comparing what I have in my opened file seems to be exactly what he has in the video.

Except I don't get the same results when running the animation.

The one in question is a particle dispersion example, where a “bed” of particles is made and an object runs through them dispersing points.

In his video as his object goes through the points it leaves a clear path showing the dispersed particles as well.

When I run it, although I can see the particles being displaced, my path doesn't get cleared. It's as if in each frame the “bed” of particles are recreated.

In the particle node he uses an expression for the “birth” of particles input:

if($FF ==1,npoints(“../point1”)*30,0)

Supposedly this statement is supposed to have the effect that these particles will only get created if its the first frame.

I have tried doing a “delete” channel to make sure it's clear while on the first key frame and entering this formula again, just in case there was something inadvertently put in while the file was created.

This is the only place I can think of that might make a difference, namely because of how he talked about the purpose of this expression. I went through the other nodes to look for settings or hints that might suggest why there is a difference but I can't seem to find anything due mostly to my inexperience.


Any comments or suggestions of where to look that might offer insight into understanding why there is a difference is much appreciated.

Thank you