Jordi, thanks very much for this. As a longtime Houdini user I often lose sight of some of the basics, and as a Houdini teacher, your perspective really helps me avoid making assumptions about how things should work

Cheers,

Peter B

Thanks Jordi

I just read the documents and very clear and usefull, I like that you focused it on Houdini philosophy.

Gracias

Hello SideFX,
And thank you Jordi for your help. I have a very specific question, not a general one. I work a lot with MOCAP(i generate the files with my own system). I bring the clips inside XSI, apply them to my model and then i clean the curves as needed. I rely heavily on 3 tools: simplify curves command, smooth curves command and animation layers. For animation layers i think there is the blend node inside chops(there is othe way?) But for the life of me i can't find simplify curves and smooth curves. At list there is something like this, or equivalent inside Houdini? I don't want the program to automatically smooth the curves(using mcbiovision) because i don't want to apply it for certain moves(knee bone curves for example). So i need to manually clean the curves myself inside Houdini. And one more thing: can the good folks at SideFX include something like 'match translation/transfromations inside Houdini? And also apply this to pivot? Thanks in advance for the help.
Thank you,
Constantin

Very rarely you will have to program things in boudini… that is number one thing… it is very well designed. Rough on some end user areas but the core is rock solid which is the reason I feel now happy about it.

Regarding your question my preferred path is

- Get your mocap in BVH format as the mcbiovision conversion command is very good, unlike the FBX import which is a bit weird and I personally don't like the setup (although I am using it at the moment)

- Once you have the skeleton moving add a CHOPs network (channel operations) to get the data from the bones and trim it, loop it, soften it, add variations with sprints, echoes and whatever you want. blend it, stitch it, sequence it and basically output after all that a BCLIP.

- Then, once you have a library of BCLIPs (like xxi animation clips) get your real skeleton that drives your mesh (with or without shadow skeleton, depending on how much you want to touch it later) and load that data.

Now the fun part starts.

- Get your character and convert it to a digital asset, add some menus to select the clip you want, then you can add some tools to operate the animation (like randomisation of curves, offsets, etc…) and presto.

Now you have a character that not only has animation but is fully aware of what is what.

I am right now using this with a not optimised skeleton and I have more than 30 clips that I am selecting in less than a minute, randomised and processed per character.

i have been able to put 170 characters in my scene without hiccups although I am starting to big memory limits (my laptop is 16Gb and as I said, it is not very optimised character)

Now, the bad news;

If you want to apply destructive curve operations like in Softimage I am afraid Houdini does not provide that functionality and here is where you can choose, do it as I explained, procedurally friendly, or (you guessed) you can run a script to do the job like in XSI. This is when you may want to write code.

And this is one my current plans, I am preparing to document all these things for SideFX to have a look (with videos) so hopefully they will see what Softimage artists really are after, sometimes it is destructive manipulations what we need.

hope it helps

Constantin X
Hello SideFX,
And thank you Jordi for your help. I have a very specific question, not a general one. I work a lot with MOCAP(i generate the files with my own system). I bring the clips inside XSI, apply them to my model and then i clean the curves as needed. I rely heavily on 3 tools: simplify curves command, smooth curves command and animation layers. For animation layers i think there is the blend node inside chops(there is othe way?) But for the life of me i can't find simplify curves and smooth curves. At list there is something like this, or equivalent inside Houdini? I don't want the program to automatically smooth the curves(using mcbiovision) because i don't want to apply it for certain moves(knee bone curves for example). So i need to manually clean the curves myself inside Houdini. And one more thing: can the good folks at SideFX include something like 'match translation/transfromations inside Houdini? And also apply this to pivot? Thanks in advance for the help.
Thank you,
Constantin

I would never compromise the culture, like I would never do for any package, nevertheless, cross-pollinating of ideas is always great and I know it will make Houdini even better.

I will jump on more XSI related parlance soon so stay tuned because I am sure many people using Houdini for many years don't even know some stuff I have found (simply because I was looking for it) Nothing funky, but for us animators very very important.


cheers

pbowmar
Jordi, thanks very much for this. As a longtime Houdini user I often lose sight of some of the basics, and as a Houdini teacher, your perspective really helps me avoid making assumptions about how things should work

Cheers,

Peter B

Hey there, thy for your hard work you put in here !!

My question is regarding to the layout you are using in your pdf. Any chance you chould share that “Phil Spicer’s layout with extra variations for
a more Softimage like approach” ?

Looks clean and ready to use, so would be nice if we could have this one as download.

Of course, no problem.

Will do on Monday..

Hey Jordi,

Fancy seeing you here!
(For those of you who don't know - we work together).

jordibares
Now, the bad news;

If you want to apply destructive curve operations like in Softimage I am afraid Houdini does not provide that functionality and here is where you can choose, do it as I explained, procedurally friendly, or (you guessed) you can run a script to do the job like in XSI. This is when you may want to write code.

I just want to add that there are ways of editing mocap data without programming (if I understand you correctly). You can directly edit per key-frame CHOP channels - but that is obviously painful due to a key every frame. However, there are workarounds (there *always* is in Houdini). You can turn a channel into a spline (will re-sample) and edit directly in CHOPs. Or, you can add/multiply/replace you own key-framed channel(s) over any other CHOP channel(s).

In fact CHOPs are amazing. It's not just for manipulating key-framed data. CHOPs is in fact general purpose signal processing framework. ie, the data channels can be of any sampling rate. ie, 44Khz - ie, audio! Yes, you can create, manipulate, process, evaluate audio, midi inputs, sensors, etc etc even in real time. You can write quite sophisticated ‘programmes’ in CHOPs. We at Realise have used it for mocap/animation editing, audio manipulation (doppler effects), controlling real time animations with light sensors/midi controllers, real time camera editing/performance capture, the list goes on…

In short, CHOPs is a amazingly powerful tool. Only one of many.

What Jordi says about programming is spot on. If your coding - then your usually (98% of the time) not doing a particular task right. So many operations can be done in SOPs, DOPs & VOPs - it's rare you need to type in code out of necessity (although it's sometimes nice to!).

Think of Houdini like ICE - but ICE everywhere in every facet of the pipeline - right up to the pixel you render. And everything speaks to everything. It's truly awesome! And I haven't even started talking about mantra/DOPs…

On a more general note, I'm very excited at the prospect of (hopefully lots) of the XSI community joining the Houdini one. I've seen some amazing work been produced by XSI - both creatively and technically. So *really* looking forward to the cross pollination. Houdini is great - but it's not a silver bullet and there's room for improvement. It's become more artist friendly in the last five years - but there's a way to go. ie, Better production ready uber shader, material mixing, modelling (maybe not the Houdini community #1 as there's other good modellers out there), graph/animation features, GUI & my personal bugbear - well designed hotkeys & workflow that enables you to “drive” Houdini like a Fighter Jet - or say - a really good game! The latter is something where there's a lot to learn from XSI, Flame & Nuke.

SESI are aware of the above - so now is a good time to be vocal and let them know what Houdini needs to be. As you will find, they are a very smart, approachable and receptive bunch.

In short - welcome all

Regards to all,

Paul Simpson

jordibares
Now, the bad news;

If you want to apply destructive curve operations like in Softimage I am afraid Houdini does not provide that functionality and here is where you can choose, do it as I explained, procedurally friendly, or (you guessed) you can run a script to do the job like in XSI. This is when you may want to write code.

Jordi, curious what this means since in CHOPs you can filter/resample then go in and manually edit your curves, or push them back onto objects as ‘regular’ keyframes etc. I am likely not understanding what you want to do though, or how Softimage does it.

Cheers,

Peter B

Thank you,
both Jordi and Paul for your answers. I think i need to go deeper into MOCAP-CHOPS in Houdini. Paul your info about fitting a spline over my existing MOCAP data so i can manipulate it is very good. I just discover things but i am already impressed. And yes Jordi, you are right, i am try to find out how to work with bclips instead of XSI clips. In XSI i bring the MOCAP, manipulate the channels, add animation layers on top of it(correct thinks etc) and then save everything out as a clip. This way i have libraries of motions(have you tried to do 4-500 small animations, like fitness without clips?. :wink: ) so i can work on very large data sets with ease. From what i see the Houdini has all the tools to get you there, it's just a bit different. Well Paul, if i am vocal i think the first requirement is ‘match transformations’. I can't tell enough good hings about this little tool and hope to see it inside Houdini too.
Constantin

The point is that like modelling, there are moment in which destructive process are what you are after.

I was referring with the ability in Softimage (and maya and max) to run filters that alter the animation in a destructive way. ultimately I think there is a fundamental realisation to happen and its that a smoothing filter for a curve or segment of a curve really is like moving the points by hand, this is the reason everybody moving from any other package to Houdini are going to feel the animation toolset is not there yet.

Hope it helps

pbowmar

jordibares
Now, the bad news;

If you want to apply destructive curve operations like in Softimage I am afraid Houdini does not provide that functionality and here is where you can choose, do it as I explained, procedurally friendly, or (you guessed) you can run a script to do the job like in XSI. This is when you may want to write code.

Jordi, curious what this means since in CHOPs you can filter/resample then go in and manually edit your curves, or push them back onto objects as ‘regular’ keyframes etc. I am likely not understanding what you want to do though, or how Softimage does it.

Cheers,

Peter B

I have a really stupid small question: is there a tool in Houdini equivalent to the tweak tool in SI? I've looked a lot and failed to find it.

AmmonsHorn
I have a really stupid small question: is there a tool in Houdini equivalent to the tweak tool in SI? I've looked a lot and failed to find it.

No there isn't. Below there's a thread dedicated to modeling and scene interaction and how to make Houdini more artistic friendly.

Destructive workflow is not that great. This happen all that day: please remove that effect, show me it with that handheld noise, switch it off, turn it on again, add 20% of that, make it 30% slower, make it 15% faster, go back to previous version you showed, remove that noise you add at beggining but keep all other stuff untouched, go back to previous version and so one.

After we do a lot of animation in SI on a lot of different stuff it's not that simple like rolling back old version of the scene. We end up with model and fcurve exporting and importing back and forth. In Houdini it's just matter of toggle on/off some node (effect). This nonprocedural editing give us in the end much faster workflow.

The best thing in animation in Houdini is way it handle tha animation curves. Adding up any expression to fcurve is super simple, no need for separate object to handle curves, reference the values and linking them with expression.

One more guide ready

https://www.dropbox.com/sh/22l2sx82m75buxj/H-0buUQAUP [dropbox.com]

HoudiniGuides_GeneralConcepts_ComparingInterfaces.pdf

enjoy

Great guides so far, even if I have not used XSI in years, they're interesting reads.

Curious. When comparing XSI Explorer, was there a reason you chose a List View as opposed to a Tree View? Tree View would allow you to dive right inside.

I remembered I was able to but didn't find it!!! thanks so much… see, you always learn a lot when trying to explain it.

Will amend the documentation. Thanks so much

I know it’s been said already but these guides are indeed great! Having the comparison between XSI and Houdini really puts it into context and makes it so much easier to get into.

Thank you Jordi! Please keep them coming

Cheers
O

And another one… I am quite happy with this one in particular… hope you like it.

I would also like to ask Houdini experts to review if it is ok and if they see any drawback on the various techniques approached… I know a few but this is a never-ending concept.


https://www.dropbox.com/sh/22l2sx82m75buxj/H-0buUQAUP [dropbox.com]

HoudiniGuides_GeneralConcepts_OrganisingScenes.pdf

Jordi, you keeping me smiling in such dark days
thank you again for the effort. it is much appreciate.