I've added muscles to a geo I'm deforming but while the bones affect the geo, the muscles are irrelevant.

I'm not able to figure out how to capture the geo and get the muscles involved. I'm probably missing something but there's very little info on the subject.

I've watched a cmivfx video on the subject but he only talks about it for 3 seconds and he uses the autorig (I'm not using that). Digital tutors has some very VERY vague things that touch on the subject tangentially.

I've also googled youtube for houdini muscles but it's more demos rather than tutorials.

Any info would be highly appreciated.

Thank you.

When you do the Capture Geometry shelf tool, there should be a pull-down menu that lets you capture using the muscle/metaball method. Change the menu to your method.

Thank you - will try it now and report back…

Thanks again

Tried it. There is the option for metaballs (no muscle). It still doesn't capture it. The bones deform the geo but the muscle is irrelevant.

Are you selecting the muscle when capturing for metaballs?

edward
Are you selecting the muscle when capturing for metaballs?

Yes, I believe that's the only thing you can select.

Ok, I finally gave this a try and here's the gotchas I've noticed:

- By default it uses a capture pose at frame 0. So you first need to make sure that you set a key at frame 0 for any parameter that you plan on animating. Otherwise, when you change the values at other frames, it will change your capture pose.

- Initially, it only captures points that are *inside* the muscles. That's actually a bit weird to me. So you should either scale your muscle so that it encloses all the points on the geometry, or use the Paint Capture Layer tool to paint in the influence (make sure you pick where muscle to paint using the pull down menu on top of the viewport).

Hope that helps!

Thank you for the help.

I still cannot get them to work properly. I'm attaching a hipnc file.

You said “So you should either scale your muscle so that it encloses all the points on the geometry, or use the Paint Capture Layer tool to paint in the influence (make sure you pick where muscle to paint using the pull down menu on top of the viewport).”

Scaling them over the skin defeats the purpose of having a muscle that slides under the skin (or more than one muscle as in triceps & biceps) and the weight painting does not work properly.

Instead of sliding under skin, they poke right through and deform in the strangest way, no matter how the weights are painted.

I could be mistaken but I think this all stems from my inability to find a way to keep the null from rotating, which in turn rotates the muscle causing the geo to go haywire.

I've read the discussion here and it helped a bit, but it's still very unclear.

http://forums.odforce.net/topic/7646-houdini-muscles-workflow/ [forums.odforce.net]

So how is the muscle sliding under the skin done? I'm lost…

Thank you

I think you just need better muscle positioning and perhaps more muscles combined with better weighting. I've attached my meager attempt. Also turn on Inflation on in the Deform Muscle SOP to see another way to help. Have you also checked out this tutorial? http://www.sidefx.com/index.php?option=com_content&task=view&id=554&Itemid=263 [sidefx.com]

PS. Check out the muscles on this rig as well: http://www.youtube.com/watch?v=h0szMFeJDu4 [youtube.com] Notice how packed the muscles are.

edward
I think you just need better muscle positioning and perhaps more muscles combined with better weighting. I've attached my meager attempt. Also turn on Inflation on in the Deform Muscle SOP to see another way to help. Have you also checked out this tutorial? http://www.sidefx.com/index.php?option=com_content&task=view&id=554&Itemid=263 [sidefx.com]

Hello Edward

Thank you very much for taking the time to help me figure all this out… Your input makes a lot of difference.

I was doing that tutorial but I find it very hard to follow due to the fact that it's such an old version. But I'm trudging through it. I wanted to reference more from the manual so I went to the “Character Adding additional bones and muscles” and was greeted by a BLANK page http://www.sidefx.com/docs/houdini13.0/character/additionalbones [sidefx.com]

A question I wasn't clear on from your returned example is:
Why does the weight paint map change depending on the muscle selected? Also, for example, if I select muscle 1 (blue) I get a map that's anything but blue… if I select muscle 2 (red) my weight map get switched to something that is anything but red…. and so on?

The tutorial I was doing before had us paint weights on a single map… here I get a different one for each muscle. I don't follow this….

See my attached example: I select muscle 3 (green - forearm) and the weight map is mostly red, blue and some purple (??). Also, if I choose this muscle which is green, my paint color is red (??)…

What am I missing here?

Thank you so much again. Wouldn't be bothering you so much if there were newer tutorials around or some resource that digs deeper into this, but all the info I get is bits and pieces from the web - not even the manual addresses this properly (see my blank page example above).

While in the Paint Capture Layer tool at the SOP level, I had changed the Visualize parameter to Selected Capture Region only so that I could see just the influence for each muscle.