I consider CHOPs an extremely elegant and fast tool for doing many tasks (complex setups, dynamics, geometry manipulation), but I find the workflow for assembling a few clips of motion very convoluted and inefficient. In a scene with many characters (or just two complex ones), it's just too complicated to save your curves, load the clips, place the sequence (or interpolate) CHOPs, adjust, export, etc.

I'd like something like this: a CHOP which would act as a f-curves container. So, instead o fetching channels, locking the fetch chop, manipulating and exporting, one would right-click on the keyed parameters in the parameter pane (or in the Channel Editor, on groups of channels, or in the viewport,on a manipulator) and choose “Create Clip”. That would automaticaly place a Clip CHOP (or another meaningful name) in a CHOPnet. (Exactly like IK chops are created). The Clip CHOP would contain the f-curves, editable. Now you can delete your original keyframes and animate another take. Then save this into another clip, and so on. At the end of the day, one would have a CHOPnet full of “takes”, ready to be sequenced and mixed, but also ready to be edited at the (original) keyframe level.
This of course could be made even more interactive (drag and drop of parameters in the CHOP viewer etc)

What do you think?

Dragos

Yah I like this idea. Really, it's an extension of NWN that's already there…about the only problem I see is that it would require a channel to be a “container”, essentially just like a network. Thus an object would contain channels, which in turn could contain networks, etc. You could essentially just make a CHOPnet right there “inside” the channel, and by default export the value up to the parent channel.

Smells like there'd be other ramifications to consider, but yup, this would be kewl…

Cheers,

J.C.

Yes, having CHOPnets “inside” of channels can be cool. Actually, this wasn't exactly what I was thinking about (if I understood correctly your post).
I pretty much like CHOPs as they behave now: you manipulate your channel then use them to override the original channel. What I don't like is that once you bring your data into CHOPs, is pretty hard to manipulate your original f-curves.
The main problem is that (as far as I know) Houdini does not have a way to store/save clips of fcurves, in a file or in an “instance” inside the .hip. You can fetch the curves and lock the Fetch CHOP, but then you have a sampled image of yor curves. As I understand, you can save those, but they are not keyframed segments, just sampled channels.
What I suggest is having a way to, let's say, right-click on a keyframed channel (or group of channels, or a whole operator) and “save” its keyframed segments in a “container” operator (CHOP). So you now have the keyframes/segments, editable. You can add keys and do whatever you want.
At the same time, you can delete the original keys, do another animation and then save this in another container. Then pipe those two (or more) containers in a Sequence CHOP or Blend CHOP, or COmposite CHOP and voila: straightforward NLA! If you realise that some keys in the first container need some adjustment, just open them in the Channel Editor and do your editing.

Dragos

Oh ok, gotcha…yah I think that was the whole idea of CHOPs was that it's working in the sampled realm…but then again you have CHOPs like the Wave or Pulse which seems similar to a function curve - you edit virtual handles that result in sampled results.

I guess they're thinking that you use the channel editor to manipulate animation curves, and I guess that what you're suggesting is to have a Channel Editor CHOP and the ability to move functions through CHOPs without necessarily committing them to a sampling rate?

Personally I find going back and forth to CHOPs a major pain and anything that can be done to make it faster/simpler would be good, which is why I biased my view on your first post.

Cheers,

J.C.

JColdrick
I guess they're thinking that you use the channel editor to manipulate animation curves, and I guess that what you're suggesting is to have a Channel Editor CHOP and the ability to move functions through CHOPs without necessarily committing them to a sampling rate?

Personally I find going back and forth to CHOPs a major pain and anything that can be done to make it faster/simpler would be good, which is why I biased my view on your first post.

Yeah, a Channel Editor CHOP is the perfect way of putting it.

On the other way, I think the CHOP way of working with sampled data is excellent. I just want the source of this data to be keyframed segments, and an easy way to (repeatedly) create those sources.

It's like you would place a Constant CHOP, create/name your channels, lock it and then (blindly) edit its channels in the Channel Editor. Instead, I'd like to animate my object in the viewport, with handles and so on, and then save my keyframed animation in a container, which keeps it editable inside but outputs sampled data, like the wave or pulse CHOPs do.
I really think this would be a great time saver especially for character work.
Hmmm, in a perfect world there would even be a hotkey which would temporarly disable your CHOPnet and key the fcurves in the “current” container on the timeline, while you adjust the viewport handles.

Dragos

which keeps it editable inside but outputs sampled data,

i think this is basically the key to it all.. would be extremely powerful indeed.. great idea. would love to see it. (also like your approach of having “takes” that could be blended, composited, etc…)

yes
that?Ls what I was thinking by posting similar question around forums
digitalyssane and other from 3d BUzz remember
I had hard time understanding that once channel is in CHOP I can?Lt have access to keyframimg as in channel editor
i had simple idea of mixing two motion as motion blend with takes
in MB what I tried before,or XSI has that animation mixer
I wonder what the use of RMB-Click on CHOP and that “Edit channels”
Why that can?Lt be enhanced to channel editor?
Also,in CE I?Lm supposed to have access to exported CHOP data with
“Toggle value options” but I couldn?Lt get it work yet

best regards,
Ben

Just for the record, folks, “blending between takes” has been in houdini for many versions now…ever since CHOPs AFAIK. I remember the first demo - a character sitting at a desk and blending between “explaining with his hands”, swinging his leg, etc. That's trivial to setup. I think the key point here is the ability to edit channels in CHOPs without committing to a sample rate. Some might argue you can do it now(just call up a chan editor and source that channel in a CHOPnet), but I think Sane's point is more of a GUI thing than anything else…dont forget that it's well and fine to have these exist directly in CHOPs - I'm sure it's do-able - but this would require you “managing” them - at some point you need to sample them if you want to mix and match them with other channels. It will require it's own overhead…

I still like the idea, though…

Cheers,

J.C.

JColdrick
Just for the record, folks, “blending between takes” has been in houdini for many versions now…ever since CHOPs AFAIK. I remember the first demo - a character sitting at a desk and blending between “explaining with his hands”, swinging his leg, etc. That's trivial to setup. I think the key point here is the ability to edit channels in CHOPs without committing to a sample rate. Some might argue you can do it now(just call up a chan editor and source that channel in a CHOPnet), but I think Sane's point is more of a GUI thing than anything else…

Exactly, it's just about workflow. I know that it's possible to do blends, mixes, sequences in a myriad of ways. But for straightforward character animation it's a little bit too complicated to setup and unflexible… It might be trivial to set up, but it takes waaay too much time.

Dragos Stefan