RIO 2 Bird Leg Rigging



Hello everyone, I was wondering how did they manage to rig the bird’s leg to go that upwards. Is it some kind of blendshape work? Or it looked like a little bit of surface sliding controls to me. What are your thoughts?


Guessing here:

If you don’t have textures stretching to deal with.

They probably aren’t using Nurbs, but that doesn’t mean you can’t use Surface operators like Fillet with poly outputs, and ensure your rig works with the history of those mesh commands still in place. Then additional history drivers can be connected and driven to define the shape of the fillet curve to the surface based on position of the leg.

This was how we’d do these 20 years ago in school.

Or something more modern, and poly output based might look like this:

Layer one:
Use poly edges as curve outputs to a nurbs surface to define the sliding area the thigh connects to along the belly.
Layer two:
Hair rivets for point on surface output to joints, with UV drivers based on a set driven key for leg position. # of hair-> joint outputs pending on fidelity required to keep edges aligned, (one per vert if scripted)
Layer three:
Additional blendshapes on set driven keys for volume and surface transition angles for thigh volume output control.
Possible Layer Four:
Normal matching on edge of thigh, where it meets the stomach. A simple script job that queries the nurbs surface normals, or original poly normals and transfers those outputs to the thigh’s connection edge. (to further help hide any seem edges)


Thanks for the reply and I think this is waaay too much technical for me :frowning:

Is there any tutorial, book or source which you can recommend for me to learn those type of techniques?

I was thinking about reading books “Complete Maya Programming” or “Python For Games And Film”.

I am open to any suggestions because I really would like to be able to experiment and develop those kind of methods.

Have a nice day!


I think there maybe a laplacian deformer happening on top to relax the topology, whilst retaining constraints - I think underneath the rig maybe driving a cage that the drives this.


Or the leg is full module, and you got a top node that adjust the global position of the leg, based on matrix extraction. When you reach a certain value on the front matrix, you start to move the top node leg.

I think they just have a blendshape to correct the skin on this position. If you look carefully you can see a big volume loss under the leg.


So you are saying that leg might be separate piece of geometry?


Nope, i don’t think on this rig. Was talking about how the leg mechanical rig is connected and manage.