Cartoon Arm Rig

[kungfudork]

I'm not sure if anyone else has tried something like this, but I thought I would share my results. I was wanting to have a simple arm setup that could easily have the forearm in front and behind the body while keeping the upper arm behind the body, or any combination of that. I found by trying to use two separate pieces for upper and lower arm, i needed to really work on where they meet, using smart bones and never really got a great result. So here is what I came up with and i feel it works really well...

WARNING...I think the volume is recored high, so turn down your speakers...sorry
http://www.kungfudork.com/DW/CartoonArmRig.swf

*I said animatable switch layers, but what I meant was setting the layers to animatable in the bone layer.

**I also realized if you do any smartbone setup on the layer, then duplicate the layer it has all the same smartbone info. So make an arm, do all your smartbone fixing, then duplicate it to follow my process. I hope this inspires or helps others....

[heyvern]

Yes this is a great solution. I have used this technique for many years. Now with smart bones it's even better.

As you said, you have to maintain two identical layers with smart bone actions.

Here's a trick I started using recently, copy/paste of points instead of duplicating layers. Vectors "store" actions in the point information. If you copy and paste vectors from one layer to another the smart bone keys are kept. Point binding is lost of course but that's easy to redo.

This may sound like extra work but it makes editing easier; I will keep a "master" arm layer during character rigging and design (set to do not render or display). Instead of editing the forearm or bicep and duplicating to fix a smart action, I will edit the "master arm" layer for smart bones and then copy and paste the entire vector shape into the forearm and bicep and delete one of the shapes. This makes editing easier because I can edit the WHOLE arm in one layer and can see exactly how they interact with each other, and I don't have to recreate shapes. Deleting an extra shape is faster than creating a shape.

The other main reason I started to work this way is because of animated layer order keys. In a perfect world you create the arm, smart bones, etc, duplicate for the forearm or bicep and you're done, you do a bunch of animation including animated layer ordering. Then you see a problem you want to fix in the points of the layer or an action. If you do the original process duplicating layers, you can mess up the layer order keys, not only in the main timeline but in all the actions. By using copy and paste instead as described above you don't mess up the layer order keys.

Another trick that is also a bit of time saver is to put the forearm in a group with masking. Yes, what a pain it might seem... but now with nested bones in ASP you can put the forearm in a group, set masking and create a basic simple mask to hide the bicep area. Now both the bicep and forearm are identical. The forearm is masked in its own little sub group layer. Now you can edit one arm and copy/paste it into the other exactly as it is.

Also having the mask for the forearm allows you to do "extra" stuff you couldn't do before. Sometimes the arm may not display correctly if it extends too far across the body. You may actually need part of the bicep to display across the body and behind. You could animate the mask points or create another smart bone to extend that mask to fix the display issue.

[Danimal]

Interesting. Now I want to try this!

[kungfudork]

Heyvern,
that was great info! I totally understand why you would copy and paste. Thanks for the input. I am loving this software!

thanks,
Dieter