Ok, I finally think this project has reached the point where I can post it for crits...

The project is a full body muscle rig for a human, the mesh used now is made with 'Makehuman'. I think I've got most of the muscles down, and the next step is to merge them into groups like the arm/shoulder file from the exchange.

Posting a turntable now, and the hip file if anybody wants it later. Any crits welcome, just hope I havent made some mistake which means I need to do it all over...

The areas under the arm and the sides of the knees will be bound using rigid skinning, as I think there are not many muscles in those areas?

Oh yeah, tell me that you made it in H9, please !

I just can't wait !

You don't have to limit the muscles just to where real ones are, you'll probably find that you only need certain ones like in the shoulder and other areas can be simplified and not follow the real muscle structure at all.

You can see the 9.0 style viewport gizmos in the top right of the viewport.

At the time I was reading this the video wasn't ready to see.

now it's later, Please

Well heres the file... only have the non-commercial here at home.

@sibarrick - so most of this work wasnt necessary? Well apart from wasting a lot of time, is it a large problem?

Yea, and this is my first real character project, after stumbling through the muscle workflow/capture tutorials, so take it apart please!
The steps I have to do now are: merge the muscles into groups (see first post), and setup the 'helper nulls' like in the muscle capture video.

Oh, and what is the correct path for opening a file on a network with houdini? the computer is called 'Athome-2' so what would the correct path to the shared folder 'Houdini' be?

I wouldn't say that, you'll only find out by trying it. But what I was trying to say was if you have problem where things don't work or you have "gaps" you mentioned there are no muscles behind the knee, and there are none all down the shin as well it doesn't matter if you still add a muscle in those places just to make the capture work. It may not be anatomically correct but it doesn't matter if it works.

Take a look at the muscle rigging video on Sidefx if you haven't already, it goes to the other extreme of using almost no muscles, certainly no "real" ones, it shows very well how muscles shouldn't always be thought of as anatomical structures, at the end of the day its what drives the skin that is important and that is a combination of things not just muscles but the whole effect can be "simulated" with houdini muscles.

Maybe Sesi shouldn't have called them muscles they are soft capture objects that's all.

Hmm.. I think I would have done it differently if they were called something else.. interesting point there... until then I'll do what u suggested and go ahead and see if I run into any problems.

I've finished merging muscles, and am now working on finishing the rest of the rig controls so I can properly test deformations later (and for a change from working with muscles/soft capture objects). For that, is there any way to visualize the range of the bones? I'm thinking something like what was done in blender which seemed pretty slick. The shaded region shows how far the bones can be moved. Is this possible?

EDIT: When I add IK to some bones they tend jump around a little, which ends up thowing some of the muscles off. Is there a way to avoid this, or do I have to live with it ?
-Maybe solved: this only seems to occur when rest angles or transform values are not 0, could this be the cause?

Also, how would I go about switching the 'length' of an IK chain. What I'm trying to do is have a switch that will let me choose if moving the hand target forward also pulls the shoulder forward, or only moves the upper arm and downwards.



Yech just noticed the rotations of the bones are a mess... time to fix that now. Is there any way to store a selection and then recall it later?
EDIT: Group them...

How do I combine bone/muscle weights for my mesh? For I can usually select metaball or bone, but not both, which makes painting weights a bit awkward.

Sorry to sound rude, but I am really stuck on what to do to get muscle and bone deformation (or even weighting) working together? I can only select metaball (muscle) or bone for the SOPS, but I can't find a merge weights option anywhere. Please help!

Have you watched the rigging tutorial on the sidefx site....

Number 4 should tell you what you need I think

Rigging weights

you can't. period.

it's bones or muscles - NOT both. (I asked SESI when metacapture was shown for the first time if there would be a unified deformer...currently the answer in no)

there are two workflows for this:
1 - use bones for articulation, then build muscles as children of these bones for defomation
2 - bones for deformation - then transfer the weighting info to muscles

I've never tried this but if you really want to combine both then can't you modify the creation script for bones so that you have a "muscle" in each bone that takes all its settings from the capture pill, then you can combine those "bone muscles" with any other muscles to do the final deformation. A single muscle set up to match a capture region should behave much the same way as the bone system, no?

"behave"..well not really...if you're talking about 'move leg control moves leg' then yes
the bones workflow includes things like
multiple captures - you have to capture your muscles all at the same time
capturing point groups - not available with muscles
the painting of attibutes is different with muscles...not as good as bones...
etc

for me the only production ready workflow with muscles is to rig and capture with bones (that have a slave muscle)
then transfer the proper attributes to the slave muscles, additional muscles, paint muscle specific things like inflate and slide etc...

Interesting, hopeful some of that will be addressed eventually, especially the capture weight painting. It would be a shame for such a good system to be unused because of a few workflow issues.

Michael, could you please explain your workflow a bit more? If I understand this, you have 'slave muscles', which are a muscle that is responsible for the deformation that would be done by the bones, as well as 'additional muscles', which are for other deformation, like muscle bulging. Is this correct?

EDIT: This is what seems to be going on in the quadruped tutorial, so I will try that and post what I come up with.

I guess the best way to describe it would be like a real creature...
bones as structure
muscles as deformers

so for a leg you'd have:


the muscles would be your capture/deform nodes, the bones would just move everything around
then within that you'd have

for inflate/sliding/shaping etc

the real problem right now is that the muscle workflow is NOT the same as the bone workflow - but they should (and can) be exactly the same...that is to say, use all the same tools and workflows.

Ah OK, I see what you mean.
I tried this with the legs, and its coming along very well. I have one problem with the inflation though, whenever I add a muscle to the 'muscles for inflation' parameter, houdini crashes with a 'segmentation fault' (build 9.1.179), is this a known problem?
I'll try it on another computer as well as soon as I can.

The muscles are not accurate particularly in the shoulder and the back. There are not 4 muscles leading into the shoulder from the scapula on the back but rather 3. The Trapizus and the Latisumus dorsi are the most important 2 muscles on the back. I am posting some links to help you out. Think these will be very useful to you.

Human Muscles and Bones
Full Pictures Bone and Muscle
Facial Bones and Muscles

Cheers,
Nate Nesler

OK, I'll take a look. Sorry for the lack of replies, school work got in the way.

@ Matrix - The yellow and purple sections are both the trapezius muscle, but as they act in different circumstances (yellow for shoulder shrug, purple for shoulder movement to the back) I decided to separate them. If that's not what you meant, please explain!

To all others (and Matrix too of course), how can I measure the rotation a bone develops from IK? I want the tendon in the wrist only to follow the hand if the rotation is under a certain value (or the wrist is pulled back through the arm).

Hi,
I tried a few things too but no results this far, so is there no way to layer deformers in houdini? The way I'd layer deformations in Maya, when all other methods fail, would be through the use of blendshapes - multiple meshes with diferent deformers or groups of deformers, each mesh piped into a blendshape and added to the base. It doesn't seem to work in houdini, I can't get a behavior similar to parallel blenshapes in Maya - basically, both blends should be relative to the base, but independent of each other. Any thoughts?

vm

er, #1 as described is "layering" to me ...

by #1 you mean... "1 - use bones for articulation, then build muscles as children of these bones for defomation"? I'm not sure I understand...

anyway, the above example is not layering any deformers, it's just one deformer - the muscles.

vm

If what you mean is to use standard point capture weighting with the Deform SOP and then using Muscle capturing with the Deform Muscle SOP, yes you can. Just have to be careful with the transforms.

That is the way muscles were first used on rigs and is still a valid approach. You are running two Deform operations so you will get a speed hit.

You can layer muscles using Muscle Groups (Metaball Groups). You can have one set of muscles doing the base deformation then layer other muscles on top as well all feeding in to a single Deform Muscle SOP.

thanks old school,

I haven't worked with muscles yet, just some basic tests. I was asking about layering deformers in general, not necessarily bones and muscles.

the problem seems to be, like with the edit sop, if you add an edit after the capture, it doesn't seem to work, or at least I couldn't find a way - the edit doesn't apply its deformations based on the results of the capture - if in the edit sop I move a vertex right and I use the bones to turn the object around, the edit doesn't turn with it, it keeps deforming in the same direction.

could you give me some hints... you said something about transforms... could you detail on this a bit please?

vm

You need to wire the rest geometry into the second input of the Edit SOP. I think I've posted more than a few examples on this already.

I already tried to do that, it doesn't work.

Sorry for abandoning this thread without a message, my project got a bit drowned during the end of the school year. I hope I'll have some time to work on it over summer, and I'll post updates as often soon as I can.

I found how to measure the bone rotations from IK, but since I started workin on this again I've been having a strange problem, when I move the IK controller up, the bones and muscles move with it, but the arm deforms downwards. The normals of the mesh are facing out, so has anybody got an idea to what's goin on?

EDIT: another issue that might have something to do with the problem: when i first add the muscledeform node there is a deformation in the mesh even though I haven't moved anything... maybe this is unrelated but I don't know what is causing this either. Thanks for any help, this is my first real character project so I'm new at this.