I want to evolve attributes over time, so that the values of an attribute depend on the values it had the frame before.

For example, the value of $ATT at frame $F depends on $ATT at frame $F-1.

I think I need the SOP solver in a dop network to achieve this. But how do I set it up?

Hey yo!
Here's a little example where you can throw different effects onto a network. The SOP Solver can be confusing to explain but is easier to grasp by looking at. Enjoy!

Thanks. That file is excellent!

I tried a pure SOP solution, which works but is very slow. DOPs are better I think.

fansastic demo file!

How can this be accomplished if the input geometry is moving?

Thanks in advance!

Well, I think that's a bit trickier. The reason the SOP solver is special is that it makes the geometry look at itself on the previous timestep. Without getting too technical, to get this to work with deforming geometry you'd need to get the amount each point is moving each frame and apply that on top of the sop solve. This is basically velocity/FPS if your timestep is 1 frame, so if you use a trail SOP to compute velocity on the geo before it goes into the sop solver you can apply that to the geo at each timestep.

Word?

Check this, I believe this should work with an animated characters, not just animated planes

Great files .

Thanks

Rob

whoa, thanks for this wonderful examples, tjeeds.