Eyeball

The Demoman's eyeball.

Alyx's eyeball in Ep2.

A vortigaunt's largest eye. The iris covers its entire surface.

Eyeball is a property of $model. It consists of two components:

A static eyeball surface on the model. Must have a unique material.
A dynamic iris 'decal' that travels over the eyeball to simulate the eye looking in different directions.

Tip:An iris material can cover the entire surface of the eye if need be.

Parameters

Tip:The qc_eyes tool can help you manage the potentially confusing string of numbers needed for this command.

<name>: Name of eyeball, used to match eyelid rules. For humans, use righteye and lefteye.
<bone_name>: The bone which the eye is parented to, typically the head.
<X> <Y> <Z>: World location of the center of the ball of the eye.
<material_name>: Material above which the iris material will be drawn. Make sure every eye has a unique one!
<diameter>: Diameter of the ball of the eye. Prevents eyes rolling inside the head. Note that this means that the iris will travel in a circle even though human eyes are oval: your model's flex should accommodate for this.
<angle>: Default yaw offset (from directly forward) for iris. Humans are typically 2-4 degrees wall-eyed. Not setting this correctly will result in either your characters appearing cross-eyed, or if you've compensated by misplacing the ball of the eye, them not tracking side to side.
<iris_material>: Material to use as the iris texture.
Todo: This now appears to be a property of the eyeball material. Need some OB QCs to confirm.
<pupil_scale>: Scale of the iris texture.

$model "female_01" "female_01_reference_RE.smd" {
   eyeball righteye ValveBiped.Bip01_Head1 -1.261 -3.702 64.974 eyeball_r 1  4 pupil_r 0.66
}