Hi!

I'm trying for some time get the feedback chop working, but without success

I understeand it can give us a channel from one frame (or time slice) ago.
In houdinis maunual, there is described that we have this node be followed by exported channel chop to sop display object, to update it.

I don't get it why on my example (see attachement), when we hit play, the feedback chop is not updating.
How can we force it to update every frame and give me the values of attrib “a1” from previous frame?

Thank you very much

please - if I'm doing something wrong I would be very gratefull ffor siimple example of using feedback chop - I simply cannot run it

Thank you

I only had a quick look at it and I don't know either, but at least it doesn't create an error now and writes values.

Thank you very much.

The strange behaviour was that i had to reconnect in your file the feedback chop.

You're using right now “animated channels”, so they're “backed” on the beginning for the whole timeline - but is there any metho to use feedback chop with parameters, that could not be backed?

Lets concider I'm painting some colors on a sphere.
I'm iporting the red channel to chops and WHILE painting I want that chops would subtract the red channel from previous frame for each point frop current red channel of these points. - How can we make something like that?

Thank you

Hi,


I am aware this was posted quite some time ago, but I am actually trying to achieve a very similar thing here.

I was looking for some accumulator solution for my sop network. Looking at the CHOP feedback's description I thought it was exactly what I needed, from its description: “Get the state of a chop as it was one frame or time slice ago”.

I tried the following: I bring the attrs from sop geometry onto a channel in CHOP. I want to have access to this channel on the next timeline frame, basically freeze this channel so I can read it back in sop at time t + 1. I use geometry CHOP network in static mode (using ‘animated’ would defeat the purpose since it would evaluate the sop net for the whole timerange). I can't figure out how to use the feedback node or if it can be used for this purpose at all. Basically, I would expect to be able to ‘freeze’ this channel so I can read it back next frame.

I am aware that this might sound ‘evil’ in sop, break proceduralism, etc. but any other solution based on simulating or re-cooking is not feasible, for performance or other reasons. The cooking of my sop network doesn't fundamentally rely on the parameter that I want to calculate here. By ‘fundamentally’ I mean, I can jump to any frame on the timeline and get the same result, it is just that very first frame evaluated that might have a different attr value, being correct from that point onwards.


Were you able to achieve what you were after with the feedback node? did you look into any other solutions?.



Thank you!!!