Make this eye node work well with armature modifier

Hi there! I haven't seen the tutorial video but I'm guessing Kent uses the Object output of a Texture Coordinates node for the procedural material.
If this is the case, you can bake the Object coordinates to a texture and then use that texture as texture coordinates in the procedural material.
Please ask again here if you need help doing this.

Theoretically, I think you should be able to use drivers for the Location, Rotation and Scale of the Mapping Node.

That is: drive the X Location of the Mapping Node to minus(!) the X Location of the Armature > Bone, and so on...

This works for the Location without any problems, but the Rotation is not so straightforward.

But still, just an idea;)

ggcs_dev 's proposition of baking the Object Coordinates to a texture sounds a lot easier!

Can you show me how to bake the Object coordinate to a texture? This is first time I heard about it :D

Make a new texture and plug the Object Coordinates into a Viewer Node (Emission). Select the Texture Node with the texture you created and Bake the Emit pass.

Then you get something like this and you can use the Image Texture instead of the Object Coordinates.

spikeyxxx is on the right track but there's a little more to do in order to account for minus numbers, and numbers greater than 1, which can't be represented by a texture.
Could you please post a screenshot of your sphere with the armature deactivated so I can see where the Origin of the sphere is?

 ggcs_dev

I deactived armature and this is the right view of the eye.

Could you check it?

Ok, it looks to me like the left side of the eye is probably all black indicating minus numbers, so we'll have to fix that.

Here's the process, step-by-step, from beginning to end:

1. UV unwrap your sphere (the automatically generated UV map will work fine)
2. Create a new Image texture 1024*1024 (resolution isn't very important but I wouldn't go lower than 512*512) and set it to 32 Bit. We'll name it "Tex Coordinates" for this example.
3. Open the Shader Editor and copy the setup below: (This setup assumes that all three dimensions of the object are the same. If this is not the case, you'll need a Value node and Multiply by 0.5 for any dimension which is different from the others.)
   Copy and paste the dimension of your object into the Value node (highlighted by the green circles)
4. Bake your texture as you did before.

Now to use your new Tex Coordinates image copy the setup below:

This Combine node (highlighted in green) is now your texture coordinates node.

I hope this is clear enough. Please do ask again if you need more help.

It's cases like this that make me REALLY miss the old "Bake to Vertex Colors" option. Does anyone know why that was removed?

Thanks Kent! The idea came to me a while ago when I wanted to use my procedural wood on a curved-back chair.

Directly parenting the object to the bone is definitely much simpler and quicker! Why oh why do I complicate my life so???

Absolutely brilliant ggcs_dev! Thanks for sharing!

(I've never used Bake to Vertex Colors, but that was Blender Internal... Maybe Eevee will get baking at some time and have that functionality????)

Thanks so much Spikey! 

I still reckon @theluthier 's solution of parenting the object to the bone instead of using vertex weights is much more efficient and easier, but it (nearly) never hurts to have one more node-based trick in our arsenal.

Man, it's that simple...

Thanks Kent!

spikeyxxx Right!? I'm headbutting my desk for not thinking of that!

ggcs_dev , spikeyxxx , @theluthier 

Oh god thanks you guys so much for helping me out.

Kent' solution is so simple and it work very well.

gcs_dev and spikyxxx method of using bake coordinate is very creative.

I will save this trick, it will be useful in someday.

You're very welcome! It's quite clear which of us three is the professional tutor, right? Bravo @theluthier !