Ok, so I've been trying get some collision info into CHOPS.

So, the documentation points to using the name “Impacts” (which causes no graph channels) in the dynamics chop instead of “Options” (which does seem to work).

There is also a cache feature on the dynamics chop, and various other things I've tried like “Impacts” in the other feild, setting numbers in the number feild etc.

There are also options on the rigid body solver to add collision data, and how to add it etc, so far no luck though.

Does anyone know how I might be able to get some collision info into CHOPS or have any example files etc?

My current file is attached.

I couldn't open your hip file for some reason, but no matter. Here's how it's done.

Also, be aware that Impact data is transient - it only exists on frames where there is an impact. You can see this if you open the Details View and single step through the simulation, watching the “ball” object in the details. Impact data will pop on, then go away.

ah, thanks so much! That was really bugging me. Makes perfect sense although I wish it was in the documentation

All this is explained in ch 12 in the ‘Magic of Houdini’ book. Kudos to Will Cunningham.

well, impacts are explained but not the dynamics chop, or much of any chops for that matter … it seems to be the least documented area of the program (unfortunately the one I'm most interested in)

I'm currently going through lots of chop examples with music synthesis etc, a bit of a brain-stretch but it's going good I think. Does anyone have any examples or tutorials on CHOPS in general I'd like some more links

andrewlowell
it seems to be the least documented area of the program

It's very sad, but it seems that CHOPs are somehow “abandoned”. They didn't receive any significant update in years (features or interface), their use and possibilities are very seldom evidentiated in the documentation and tutorials, their integration with the rest of Houdini hasn't evolved at all since Houdini 4/Touch 101. I suppose this state of facts has something to do with the fact that their architect, Greg Hermanovic, is now developing Touch.
I really don't understand how this software had for years the most powerful and creative editor for channel data and motion and those features are let to slip behind.
Even worse, when there's talk about a new version of Houdini, updates to CHOPs are NEVER mentioned.
They should be integrated with takes and the channel editor, their interface should be updated, making them a viable “visual expression editor” and NLA.

And yes, CHOPs are, even in the state they are now, one of THE top 3 killer features of Houdini (for me at least).

Dragos

being a former / or at least non-income dependent audio engineer/beat maker I find chops the most fascinating part of Houdini. With the dynamics chop I got a torus to bounce across the ground and generate random sounds which were recieved by a stereo pair of Houdini microphones.

O well, at least after learning Houdini for a little over a month I've gotten into a part of the program most people haven't. What prompted my interest in Houdini was the fact that I tried for a few months with 3d studio max to develop a midi-java-3dsmax plugin to take in MIDI data, only to run into constant brick-wall compatibility issues. Houdini has this ability nativly which I think is great.

personally, I don't mind if they don't update these features, they are still 10 years ahead of their time … JUST PLEASE DON'T TAKE THEM AWAY!!!

At the risk of beating a dead horse, allow me to second/third this sentiment.

As always, a problem has many solution, that being said, I find CHOPs indispensible…

Cheers,

G

I justy want to add that Ive been playing with CHOP's a lot this past week and put it this way I really dont know why I would ever go back to using maya .

CircusMonkey

CHOP, CHOP, what's that, is the first impression for ewverybody that haven't seen it before, is one of this piece of sftware that make a tool like Houdini unique, a unique paradigm to solve problems, a unique sandbox to solve many situations and to create crazy things.
And I am not agree with digitallysane, maybe CHOPs need some update but it have been integrated with many of the last houdini features, all the character animation relies on CHOPS, you have the Dynamics CHOPS to connect the new DOPs with it, etc… I only miss some ui update to make it a little easier to use.
But CHOPS man are difinitely great, i am sure that the people from SESI know it because everytime you see how they made things they are using CHOPS a lot.

lisux
all the character animation relies on CHOPS, you have the Dynamics CHOPS to connect the new DOPs with it, etc… I only miss some ui update to make it a little easier to use.

It's not all the character animation, it's just the IK solver who sits there. And it's not “some” UI updates but the whole interface and integration should be redone, not to make it “a little easier to use” (what's the benefit in that) but to bring a lot more power to the entire Houdini workflow.

Dragos

digitallysane

lisux
all the character animation relies on CHOPS, you have the Dynamics CHOPS to connect the new DOPs with it, etc… I only miss some ui update to make it a little easier to use.

It's not all the character animation, it's just the IK solver who sits there. And it's not “some” UI updates but the whole interface and integration should be redone, not to make it “a little easier to use” (what's the benefit in that) but to bring a lot more power to the entire Houdini workflow.

Dragos

Ok maybe not all, but now is difficult to imagine a character without any Ik/FK solver this is the reason because i have said it, almost the 99% of the character use CHOPs.
But maybe this is another discussion ….

once again I'm very new to Houdini and I'm sure I'm not saying anything new here but I see a lot of potential with crowd animation and chops using chop-copy-stamping.

I recently wrote a pretty big script (maybe 8 printed pages) in 3ds max to animate a few thousand characters and add in variation etc for a commercial project.

Without knowing much about Houdini I got a more advanced version of the logic to work in around a day by copy-stamping chops, and only one expression script on the geometry level in Houdini that I later found out I didn't need.

What I'm very impressed with is how Houdini doesn't differenciate between a motion curve and other types of values like impacts, sound waves, midi triggers, geometry deformations etc. I guess chops are kind of like a photoshop “rasterizing / sampling” for motion.

Everything I've read and heard so far does suggest that they are very misunderstood and underused compaired to other parts of the program such as procedural modeling and particle logic.

andrewlowell
What I'm very impressed with is how Houdini doesn't differenciate between a motion curve and other types of values like impacts, sound waves, midi triggers, geometry deformations etc. I guess chops are kind of like a photoshop “rasterizing / sampling” for motion.

Exactly. Working with chops is like working with rasters (versus working with vectors), and they offer the same advantages a raster program has over a vector drawing one (and the same limitations, of course, but that's why we have the cannel editor).

Dragos