Customizing the New Auto Face Rigger

   535   9   2
User Avatar
Member
37 posts
Joined: Jan. 2017
Offline
This is a question for those of you who has had experience with rigging characters inside of Houdini Indie. Suppose I wanted to create some new custom facial controllers that can work with the ones that come with using the new “Automatic Face Rigging” feature inside of Houdini Indie. What would be the tools that I need to use and the steps that I need to take to accomplish this task? Would it be possible to achieve results that are similar to what is being seen in the video that I have included a link for with this post?

https://www.youtube.com/watch?v=DGG9TGJ9tWc [www.youtube.com]
User Avatar
Member
318 posts
Joined: June 2014
Offline
Hi,

Thanks for the link, that's a really nice looking rig Very comprehensive.
Did you check out some other pages discussing it? www.olivier-ladeuix.com [www.olivier-ladeuix.com]

There's some ongoing links from there to where Spiel Kind was running through their working process.

Lots of blendshape work here, apparently 27 shapes which were then split up and masked out to create 90 separate shapes. This then combined with ‘joints’ (bones) to control broader deformations.

The connecting of control objects to blendshapes is likely to be done with ‘set driven keys’ as they are called in maya, with the houdini equivalent being ‘blend poses’ which uses the blendpose chop [www.sidefx.com] which in turn is created by the corresponding shelf tool [www.sidefx.com].

The rig for the lips seems to be a classic ‘zipper’ or ‘sticky lips’ setup, which you can google to find out more about, but there's a starting point here [vimeo.com] or here [www.kimonmatara.com]. The eyelids look like they contain very similar techniques, and have the really nice feature of being able to pose the gesture of the closed eyelid. Of course both of the resources I linked to there are aimed at rigging in maya, so there is some translation work to be done, but they should give you an idea of how the solution is structured.

There's a lot of ground to cover in a rig like this (facial rigging in particular tends to see riggers flexing every technique in their toolbox! ), so personally I would pick one of the above mentioned techniques and really get a handle on that before tackling the whole shebang. You will learn HUGE amounts from this. The ‘sticky lips’ setup for example will have you working through things like:

  • understanding point/parent constraints
  • averaging point positions in SOPs between the upper and lower lips curves combined with:
  • understanding ‘layered’ deformations, and the use of ‘drive’ geometry (the underlying curves)
    i.e. ctrl obj -> drive geo -> capturing bones -> character mesh
  • and blending of attributes along the length of the curve (being able to make one part of the curve sticky whilst leaving the rest open), as driven by a parameter - you can pick your poison from chops or expressions here

I don't know how much of this stuff you are already comfortable with, so I do apologise if I'm preaching to the choir

On the other hand, if you are starting out, try to break things down and make yourself comfortable with each part of the process. Check out videos demoing rigs you really like and try to find any resources that refer to the techniques used, you can learn shed-loads from seeing approaches in all different software packages, it is this that will help you ask the ‘right questions’ to yourself when sitting down to rig in H… it's a fair amount of detective work, but (I strongly believe) you will be a better rigger as a result!

Oops, that was long… not sure how useful it was, but I do hope that helps in some way.

Cheers,
Henry
Henry Dean
User Avatar
Member
37 posts
Joined: Jan. 2017
Offline
friedasparagus
Hi,

Thanks for the link, that's a really nice looking rig Very comprehensive.
Did you check out some other pages discussing it? www.olivier-ladeuix.com [www.olivier-ladeuix.com]

There's some ongoing links from there to where Spiel Kind was running through their working process.

Lots of blendshape work here, apparently 27 shapes which were then split up and masked out to create 90 separate shapes. This then combined with ‘joints’ (bones) to control broader deformations.

The connecting of control objects to blendshapes is likely to be done with ‘set driven keys’ as they are called in maya, with the houdini equivalent being ‘blend poses’ which uses the blendpose chop [www.sidefx.com] which in turn is created by the corresponding shelf tool [www.sidefx.com].

The rig for the lips seems to be a classic ‘zipper’ or ‘sticky lips’ setup, which you can google to find out more about, but there's a starting point here [vimeo.com] or here [www.kimonmatara.com]. The eyelids look like they contain very similar techniques, and have the really nice feature of being able to pose the gesture of the closed eyelid. Of course both of the resources I linked to there are aimed at rigging in maya, so there is some translation work to be done, but they should give you an idea of how the solution is structured.

There's a lot of ground to cover in a rig like this (facial rigging in particular tends to see riggers flexing every technique in their toolbox! ), so personally I would pick one of the above mentioned techniques and really get a handle on that before tackling the whole shebang. You will learn HUGE amounts from this. The ‘sticky lips’ setup for example will have you working through things like:

  • understanding point/parent constraints
  • averaging point positions in SOPs between the upper and lower lips curves combined with:
  • understanding ‘layered’ deformations, and the use of ‘drive’ geometry (the underlying curves)
    i.e. ctrl obj -> drive geo -> capturing bones -> character mesh
  • and blending of attributes along the length of the curve (being able to make one part of the curve sticky whilst leaving the rest open), as driven by a parameter - you can pick your poison from chops or expressions here

I don't know how much of this stuff you are already comfortable with, so I do apologise if I'm preaching to the choir

On the other hand, if you are starting out, try to break things down and make yourself comfortable with each part of the process. Check out videos demoing rigs you really like and try to find any resources that refer to the techniques used, you can learn shed-loads from seeing approaches in all different software packages, it is this that will help you ask the ‘right questions’ to yourself when sitting down to rig in H… it's a fair amount of detective work, but (I strongly believe) you will be a better rigger as a result!

Oops, that was long… not sure how useful it was, but I do hope that helps in some way.

Cheers,
Henry

Thank you very much for this detailed response Henry! Although I am comfortable with using Maya for my rigging needs and I am familiar with some of the systems you mentioned in that program like point/parent constraints, I am still feeling my way through Houdini as time allows me to as a rookie. In Maya I used to create set driven keys for vertex groups that I could manipulate with custom curve controllers, so I think “chops” and “blend poses” is what I need to focus on with my research at the moment since translating what I have learned from Maya into Houdini is my current goal with the program. Since the “Auto Face Rigger” can handle the rigging the jaw and connecting the eyes to the body right now, I am now wondering if it would be hard to do something similar for the teeth and tongue. I have also seen some video tutorials where the body for the character rig was split up into various parts while the blend shapes are made, like for the hands and for the head. Duplicating the head geometry to make the various blend shapes isn't a problem for me, but I do admit that I am rather intimidated by the idea that I might have to break apart the original geometry for the body. Is this a valid concern for me to have?
User Avatar
Staff
2930 posts
Joined: July 2005
Offline
you can add/extend the rigs produced by the Autorigs as much as you want - think of them just as a base starting point.


WaterBirdx2
Duplicating the head geometry to make the various blend shapes isn't a problem for me, but I do admit that I am rather intimidated by the idea that I might have to break apart the original geometry for the body

you DO NOT have to make duplicates of your mesh to create Blendshapes in Houdini.
see the attached file.
you can use a copy, or just make a series of changes to the mesh to produce the shape you want - then use the ‘sopcreateedit’ command - open a Textport and type: help sopcreateedit
this will make an Edit SOP that contains just the delta of your original mesh and the edited mesh - now you can get rid of any duplicate meshes and edits you might have made.
I'll be doing a full tutorial on this at some point - busy doing another tutorial series right now
Michael Goldfarb | www.odforce.net
Senior Technical Director
SideFX
www.sidefx.com
User Avatar
Member
37 posts
Joined: Jan. 2017
Offline
arctor
you can add/extend the rigs produced by the Autorigs as much as you want - think of them just as a base starting point.


WaterBirdx2
Duplicating the head geometry to make the various blend shapes isn't a problem for me, but I do admit that I am rather intimidated by the idea that I might have to break apart the original geometry for the body

you DO NOT have to make duplicates of your mesh to create Blendshapes in Houdini.
see the attached file.
you can use a copy, or just make a series of changes to the mesh to produce the shape you want - then use the ‘sopcreateedit’ command - open a Textport and type: help sopcreateedit
this will make an Edit SOP that contains just the delta of your original mesh and the edited mesh - now you can get rid of any duplicate meshes and edits you might have made.
I'll be doing a full tutorial on this at some point - busy doing another tutorial series right now

That sounds excellent arctor. I am a big fan of visual aids, but I do not see an attached file to your post though. Do you post your tutorials to just this website, or are they available at other websites too? Is it also possible to create a preset out of a custom rig so that it could be applied to similar characters inside of Houdini? I know that the program has some functionality like that in regards to applying a pose that was created with one character onto a different character by using the pose library, so I think that getting a better understanding of parameters like this will make it easier for me to manage the development time for my characters.
User Avatar
Staff
2930 posts
Joined: July 2005
Offline
oh, haha, sorry - I was going to make a quick example file - then I got called away and forgot all about it…
I'll post one later today




ok - here is a quick file:
there is a bunch of stuff going on here so have a good look through it, I only cover some of the uses of ‘sopcreateedit’
if you have any questions just ask…
Edited by goldfarb - Dec. 5, 2017 15:10:46

Attachments:
sop_create_edit_example_16.5.hip (954.3 KB)

Michael Goldfarb | www.odforce.net
Senior Technical Director
SideFX
www.sidefx.com
User Avatar
Member
37 posts
Joined: Jan. 2017
Offline
arctor
oh, haha, sorry - I was going to make a quick example file - then I got called away and forgot all about it…
I'll post one later today




ok - here is a quick file:
there is a bunch of stuff going on here so have a good look through it, I only cover some of the uses of ‘sopcreateedit’
if you have any questions just ask…


Wow, thank you for sharing this with me arctor! This is quite enlightening . I hope you will be able to post your video tutorial soon, especially if the ‘zipper’ or ‘sticky lips’ setup will be mentioned. I would enjoy exploring concepts like that inside of Houdini.
User Avatar
Staff
2930 posts
Joined: July 2005
Offline
right now (I mean actually right now) I'm recording a series of rigging tutorials for a standard Biped, very much in the style that would be familiar to a rigger coming from a Maya background, but no facial rigging (apart from a jaw and simple eyes). After that I'll be doing a series on capture and deform and theeeeen some facial rigging…so it'll be a while before I can get to them. But I'd say jump in and see what you can do - and ask any questions here, I'll try to help where I can and there are plenty of others willing to offer advice as you've already seen.
Michael Goldfarb | www.odforce.net
Senior Technical Director
SideFX
www.sidefx.com
User Avatar
Member
37 posts
Joined: Jan. 2017
Offline
arctor
right now (I mean actually right now) I'm recording a series of rigging tutorials for a standard Biped, very much in the style that would be familiar to a rigger coming from a Maya background, but no facial rigging (apart from a jaw and simple eyes). After that I'll be doing a series on capture and deform and theeeeen some facial rigging…so it'll be a while before I can get to them. But I'd say jump in and see what you can do - and ask any questions here, I'll try to help where I can and there are plenty of others willing to offer advice as you've already seen.

Hey arctor. Hope you're doing well today. May I ask you a couple of questions real quickly? The first question is this - where do you usually post the tutorials that you make online? I forgot to ask you that the last time that I was logged in at this forum . The second is this - how does the license renewal process work for Houdini Indie? I am about to do so for the first time and I heard that it can be quite the stumbling block for users. That is why I would like to renew my edition of the program to a multi-year license if it is possible.
User Avatar
Staff
2930 posts
Joined: July 2005
Offline
my tutorials are posted to the SideFX Tutorials section:
https://www.sidefx.com/tutorials/ [www.sidefx.com]
and to our Vimeo page:
https://vimeo.com/goprocedural [vimeo.com]

questions about licensing are best answered by our support folks
support@sidefx.com
Michael Goldfarb | www.odforce.net
Senior Technical Director
SideFX
www.sidefx.com
  • Quick Links