Rigging Question: Rubber Hose style arms

[Gibble]

Hey Gang!
I have a rigging question on how to set up arms.
It is a single rubber hose-style arm that can appear both 1. behind the torso as well as in 2. front of the torso.
Here's the additional notes:

• Arm is a single piece, not two;

• Arm is bendy, rubber-hose style, single tube using a curver

• Arm has a texture

Below is what I want to achieve.
Q: Any suggestion how I can set this up?
Q2: Are Vitruvian Bones the way to go??


TEXTURE: And to possibly further complicate things, there is a texture involved.
Below is a snapshot of the actual model's torso along with the arms.
It is a vector arm with a texture image masked within it. See below:


One idea I had was to duplicate the arm and place it above the torso- and just omit the top section.
But the problems that arise with this is that 1. you'd need to animate two arms [FG arm _ BG arm] perfectly together instead of just one and 2. they still wouldn't align perfectly.

I am sure others have ran into this already though- so I am looking for ideas and solutions.
THANK YOU!!!

[slowtiger]

Make one arm the reference of the other, so you animate only one of them, and switch visibility when needed.

At the shoulder you need to adjust points carefully.

[Greenlaw]

The setup you have should work.

In the past, I've used two types of setup:

1. The setup you showed in the above post is one. This setup works great for bendy arms so long as you don't need them to make wavy wiggles or a loop. For that I use...

2. A bone chain created and animated using Sketch Bones. I can sketch-pose very complex shapes using Sketch Bones. It's my favorite way to animate tails, and I've used it for character arms, too.

Method #1 is tricky if you're using a bitmap image, though. I had to do that when I did development work for Archibald's Next Big Thing. It was doable but trickier to set up than vector art and required more planning. Well, at the time anyway; I haven't had to do this recently, but it should be easier to do in Moho 14 using Curver.

For method #2, I used to only use the bone chain, bone using bones alone requires precision to get smooth bends. In general, I've found that Curver deforms vector art more smoothly than bones, but it's harder to animate with. So, I like to combine the two methods by binding Curver to the Sketch Bones chain. This gives me the best of both worlds. (It's how the 'artist' character's tail is set up in our tutorial videos.)

As for switching between sub-rigs, yes, use Vitruvian Bones...that's what it's for! I used switch between sub-rigs by offsetting the different arm rigs off-camera and hiding them using Victor's old 'rig-switch' trick, but nowadays, this is a lot easier to do using Vitruvian Bones.

If I were setting up a character with normal arms and bendy arms today, I would use Vitruvian Bones for the normal arms and both bendy setups (Curver with two arm bones, and Curver with a Sketch Bones chain.) This setup gives me a lot of fun cartoony ways to animate the character.

[Gibble]

Make one arm the reference of the other, so you animate only one of them, and switch visibility when needed.

At the shoulder you need to adjust points carefully.

Thank you for your suggestion @slowtiger. It is greatly appreciated.
I have never used a 'Referenced Layer' before but I tried it- and I think that will be a simple yet suitable solution for what I'll need.

Steps:

1. Select the Arm Layer; R-Click > Reference Layer
2. A new referenced layer of the Arm is created. Moved the new Referenced Arm Layer above the Torso Layer
3. Adjusted upper arm so it is not appearing to be above the torso.

Is that what you were suggesting? If so, these first tests are looking like it should work!
Follow up questions:
Is there any benefit to making this new arm setup into a Vitruvian Bone??
Maybe make two versions of the arm?
1.The lone arm [behind torso arm]
and
2. as a lone arm [behind torso arm] + referenced arm [above torso arm] ??

[Gibble]

The setup you have should work.

In the past, I've used two types of setup:

1. The setup you showed in the above post is one. This setup works great for bendy arms so long as you don't need them to make wavy wiggles or a loop. For that I use...

2. A bone chain created and animated using Sketch Bones. I can sketch-pose very complex shapes using Sketch Bones. It's my favorite way to animate tails, and I've used it for character arms, too.

Method #1 is tricky if you're using a bitmap image, though. I had to do that when I did development work for Archibald's Next Big Thing. It was doable but trickier to set up than vector art and required more planning. Well, at the time anyway; I haven't had to do this recently, but it should be easier to do in Moho 14 using Curver.

For method #2, I used to only use the bone chain, bone using bones alone requires precision to get smooth bends. In general, I've found that Curver deforms vector art more smoothly than bones, but it's harder to animate with. So, I like to combine the two methods by binding Curver to the Sketch Bones chain. This gives me the best of both worlds. (It's how the 'artist' character's tail is set up in our tutorial videos.)

As for switching between sub-rigs, yes, use Vitruvian Bones...that's what it's for! I used switch between sub-rigs by offsetting the different arm rigs off-camera and hiding them using Victor's old 'rig-switch' trick, but nowadays, this is a lot easier to do using Vitruvian Bones.

If I were setting up a character with normal arms and bendy arms today, I would use Vitruvian Bones for the normal arms and both bendy setups (Curver with two arm bones, and Curver with a Sketch Bones chain.) This setup gives me a lot of fun cartoony ways to animate the character.

Thank you for the help, DR. I already had the rubber hose arms working successfully with a curver based on your help from a while ago. But I like the Sketch Bones idea as well and I can see that being helpful for specific implementations as well. My question here was mainly to figure out how to get the rubber hose arms to appear both behind the torso [upper arm] as well as below the torso [lower arm]. I think @SlowTiger's suggestion of making a Referenced Layer might be the simplest way to achieve that. That said...

(note- I asked this question in the above post too but-)

Vitruvian Bones: They're new to me- so I'm thinking its time to apply it to this arm set up. Would it be smart to make the main Vitruvian Arm to be the Lone (orignal) Arm?
And the 2nd Vitruvian Arm to be the 1. Lone Arm + 2. the Referenced Partial Arm??

[Greenlaw]

Hi, Gibble!

Sorry, I sometimes skim posts, and I must have missed that detail. I use a technique similar to what slowtiger is describing but with a few differences:

To get an arm to appear to wrap around a torso, I just split the shape at the elbow, then duplicate the shape. Then I knock out the different sections of each arm, so I wind up with two halfs in different layers. Keep all the curves in both halves though; you only want to knock out he shapes, not the curves. This ensures the the two haves will deform as if they were still a single layer. Also, because the art is physically split in halves, no masking is necessary. I used a couple of different masking techniques in my earlier DreamWorks animations, but I abandoned these techniques because masking arm sections was a hassle to setup and, IMO, never worked as well as just splitting the arm artwork.

After setting up the two halves in two layers, I pick one of two methods:

1. When I have time to set this up, I prefer to duplicate both sets of layers in front of and behind the torso, for a total of four layers. Then I setup a Smart Bone to animate different combinations of Visibility to get the the desired wraparound effect.

2. When I'm in a hurry, I'll just enable Animated Layer Order and move the layers manually. This works fine, it's just a little extra work. Color coding the layers makes it easier to identify the layers in the Layers window.

Tip: Don't use Animated Layer Order inside a Smart Bone Action. It works but it also invites potential conflict to the rig, especially if you need to add layers or perform a different stacking order than what the Action is set up for. This conflict won't happen when using the Smart Bone to control Visibility. What I like to do is I setup the Visibility Switch as my main wraparound method, and enable Animated Layer Order so I can manually make adjustments as the situation arises, so best of both worlds.

One more thing to watch for: when splitting the art like this, you will probably see a seam in the elbow when you render it. This only happens when the art is split into two layers, and to correct this, you need to add a single point on a line where the seam appear, and drag the point so the shape slightly overlaps the line in the other layer. (Alternatively, you can render with no antialiasing and use a post-process effect to apply antialiasing. This requires using a compositing program like After Effects or Fusion.)

I think the main difference with my suggestion is that I'm duplicating a layer, not referencing it. Reference layers have been wonky for me, so I tend to avoid them. (Search for this topic to learn the things that can go wrong.)

Hope this helps.

[Gibble]

Hi, Gibble!

Sorry, I sometimes skim posts, and I must have missed that detail. I use a technique similar to what slowtiger is describing but with a few differences:

To get an arm to appear to wrap around a torso, I just split the shape at the elbow, then duplicate the shape. Then I knock out the different sections of each arm, so I wind up with two halfs in different layers. Keep all the curves in both halves though; you only want to knock out he shapes, not the curves. This ensures the the two haves will deform as if they were still a single layer. Also, because the art is physically split in halves, no masking is necessary. I used a couple of different masking techniques in my earlier DreamWorks animations, but I abandoned these techniques because masking arm sections was a hassle to setup and, IMO, never worked as well as just splitting the arm artwork.

After setting up the two halves in two layers, I pick one of two methods:

1. When I have time to set this up, I prefer to duplicate both sets of layers in front of and behind the torso, for a total of four layers. Then I setup a Smart Bone to animate different combinations of Visibility to get the the desired wraparound effect.

2. When I'm in a hurry, I'll just enable Animated Layer Order and move the layers manually. This works fine, it's just a little extra work. Color coding the layers makes it easier to identify the layers in the Layers window.

Tip: Don't use Animated Layer Order inside a Smart Bone Action. It works but it also invites potential conflict to the rig, especially if you need to add layers or perform a different stacking order than what the Action is set up for. This conflict won't happen when using the Smart Bone to control Visibility. What I like to do is I setup the Visibility Switch as my main wraparound method, and enable Animated Layer Order so I can manually make adjustments as the situation arises, so best of both worlds.

One more thing to watch for: when splitting the art like this, you will probably see a seam in the elbow when you render it. This only happens when the art is split into two layers, and to correct this, you need to add a single point on a line where the seam appear, and drag the point so the shape slightly overlaps the line in the other layer. (Alternatively, you can render with no antialiasing and use a post-process effect to apply antialiasing. This requires using a compositing program like After Effects or Fusion.)

I think the main difference with my suggestion is that I'm duplicating a layer, not referencing it. Reference layers have been wonky for me, so I tend to avoid them. (Search for this topic to learn the things that can go wrong.)

Hope this helps.

Thanks so much for the updated explanation, DR. It is greatly appreciated. I appreciate knowing the differences between all the possible solutions- and learning that they're not all equal. I never would know the differences amongst all the solutions so I appreciate getting expert tips from Moho vets like yourself and @SlowTiger. It provides me with much more options than I could have discovered on my own., THANK YOU!!!

[sang820]

I just recorded a video that may help you. This is a very old and ancient technique ~ it exists in moho5 ~ I wish you good luck

[Tunde]

I just recorded a video that may help you. This is a very old and ancient technique ~ it exists in moho5 ~ I wish you good luck

i just watched this solution. it's beautiful. thank you

[Greenlaw]

That's what I do. Switching sub-rigs is what Vitruvian Bones was created for. Previously, we built sub-rigs (like a rubber hose arm) off-camera and swapped their positions using a Smart Bone. Vitruvian Bones makes swapping the rigs much easier.