Here’s simple eye region model with eyeball. Goal for this tutorial is to make few blend shapes for 4 position of eye and drive that blend shapes automatically as eye ball rotating. Also on the end of tutorial we will learn how to make expressions and rig to control rotation of eye over translation of one nurbs circle.
First we need to make 4 blend shapes for all eyeball positions. For position where eye ball looking : up, down, left and right.
Easiest way to do that is to use clusters. First we gonna make cluster for upper eyelid. You need to select vertices of area that you want to make influence for that cluster ( a bit wider than you need )
And than make a cluster : Create deformers / cluster. You’ll get a “C” sign somewhere in middle of the eye object. That’s node for cluster.
Now if you select object and go to edit deformers/paint cluster weights tool you’ll get black/whit feedback on model. That represents influence of cluster on object. Whit means 100% influence, black means no influence.
First go to side view and select cluster. Press insert key on keyboard and move pivot to center of eye object co rotation matches eye shape.
Now we need to paint influence nice to drive upper eyelid correctly. Select object if eyelid and use paint paint cluster weights tool to make nice gradient influence, darker on corners of eyelid and brighter on center. So you get nice falloff and nice deformation when you rotate cluster.
Tip : First pain in white just upper eye lid and in black all other parts. Change brush to “replace” paint operations in settings for paint tool and paint corners of upper eye lid with 0.5 value. Than change paint operation to smooth and press FLOOD couple of times and you should get nice and smoothed result. Like on picture below
If you painted all nicely when you rotate cluster you should be able to close your eye like an blink.
Now do the same procedure for lower eyelid. So your weights for lower eyelid should look something like :
And completely closed eye should look like :
So now we can easily make all blend shapes we need…
1. When eye looks up
2. When eye looks down
3. When looks left
4. When looks right
Here’s normal eye shape when looks in front:
Here’s when looks up:
Down:
Left:
And finally last one… one right:
This is how your blend shapes need to look like… so when you make eye shape to look like on picture just press SHIFT + D and make copy of that shape and move to side… than next one.. copy.. move to side.. until you have all your blend shapes duplicated. When you have all of them put you base eye in start position by putting 0 to rotation values for both clusters.
Then delete clusters on your eye so now you have just object like on start of tutorial. No clusters, no extra nodes and deformers.
Here is how scene looks now with all blend shapes on side and base mesh reseted to start position and clusters deleted!
Now lets put those shapes to blend shape node of eye! Select all shapes and than SHIFT + Select base mesh. When you got them selected in that order go to animation panel in maya and go to Create deformers / create blend shape
So now you should have 4 blend shapes in objects stack. New deformer on eye shape that aloves you to morph your base shape in every one of those 4 that you made and combinations between them!
If you open blend shape window which is in window/animation editors/ blend shape you should see 4 sliders that aloves you to morph your base shape and change his shape..
We gonna use those shapes to drive them to follow eye movement with driven keys!
So let’s setup this scene fast. We gonna make some basic shapes like circle and square for that.
Make one nurbs square 4x4 and one nurbs circle with radius of 2 and place them like in picture. To place circle in the middle of square!
Like this…
Selct circle and square and freeze their transformations to reset all transformations and rotations to 0.
Now open attributes for circle and in limit transformations for translation limits put like this. This limits translation of circle by axis.. so I limited cirle to move from -2 to 2 in axis so you cant move circle out of square.
So when this is prepared lets make driven keys!!
Open driven keys editor which is in Animate/set driven keys / set . New window should pop up!
Select eye ball and freeze it’s transformations. You don’t need to do that if all translations and rotations are 0 and eye looks in front!
Now select eye ball and in driven keys window click on LOAD DRIVER button
Select eye socket model and in stack select Blend shape node and click LOAD DRIVEN
In driver section choose rotate Y and in driven like in picture! On left side blends hape node, on right all 4 blend shapes!
And press KEY button. Now first key is placed. So now we set that for that 0 rotations of eyeball all morph targets are zero. But for now just Y axis of eyeball!
Now select eyeball rotate 30 degree on Y axis and in blends hapes put “base4” blend hape on 1. Coz that blend shape is for eye that looks on right side.. so now eye rotation and lids are matching! And press KEY again. Now if you try to rotate your eye in neutral position 0 Y rotation eye lead should follow.
Put rotations on 0 again. Now for driver still is selected Rotate Y but in driven is selected base 3. Press Key again. Now we placed key for neutral position for that blend shape. Now rotate eye in – 30 by Y axis, put base 3 blend shape on 1 and pres KEY again. If all done right now eye leads should follow eye on Y rotation from -30 to 30 degree.
Now repeat same steps for Z axis. Put all eye rotations on 0. Select rotate Z in driver section of driven keys window. Base 1 and bas 2 for driven. And place key for neutral pose. Than rotate -20 by Z move matching blend shape for that position and place key… same for the 20 degree by Z. if all set up correctly you should have fully driven eye leads by eye ball.
See the test movie_1 that I made for testing this stage of rig!
Now lets make same thing for eye to be driven by circle.
Open again driven keys window but now load circle as driver and eye as driven.
For circle mark translate Z and for eye ( driven ) rotate X Y Z like on next picture:
Place key for neutral position. Move your circle on one side and rotate eyeball on that side and place key.. same for the other side.
Than change in driver on Y axis place key for neutral position. Move circle up and rotate eye to look up and place key again. Than for down side like before.
And it’s finished! You have complete eye rig!
Now it’s time to test. If you fallowed all steps correctly it should work fine. You can find animations of how it works on the forum, just go to the top of the page.
Hope you find this useful.