diffencerence with particle sop and popnet sop

[leo3d]

anyone can tell me what difference with particle sop and popnet sop .and what shall i do to make spiral force and vortex force field in popnet.

[old school]

The particle SOP is a black-box particle solution. No way to get inside it and play with variables at all. You just add the supported particle SOP attributes ( P, velocity V, normals N, life, etc.) on your input geometry, pipe in some colision surfaces, pipe in your effector magnets and forces, then out comes a particle system. No expressions supported in any of the fields that are point specific.

You can see why we added POPs. They get around all these issues and more.

I still use the particle SOP for quick particle simulations but ever since we properly in-lined the pop SOP, that need is less and less now.

Now for the history lesson...

At the time POPs was developed, there was a company called Wavefront and they had a package called Dynamation which was a rules-based particle solution. You wrote your rules then executed them to generate particles. You would have absolutely no feedback or control as to how the rules were executed. POPs solved that, and just in time as Wavefront got swallowed and Dynamation shelved.

The particle SOP is real oldschool . Way back in the day, there was this software called Prisms and had a module called Action and the particle SOP was all we had to do simulations. It did an incredible amount of cool effects for feature film. Early versions of Houdini relied on the particle SOP as well.

Pops were an answer to the growing need for a more sophisticated particle system and were introduced around Houdini 2 (I think, it's been so long now...).

Now if you actually have heard of Wavefront (not Alias-Wavefront, now known as just Alias for now and in a year from now just Al ), Dynamation and Prisms, well then good on ya.

-jeff

[leo3d]

thank you very much