Setting Scale Z of object to zero for complete movie? I am using Blender for research purposes, analyzing eye movements of participants watching a movie. This can be done with blender and DynAOI: Add an object as Area of Interest in Blender (setting the movie as background image, then modeling an object over the person you're interested in) and then DynAOI matches weather participants were looking at or away the AOI. 

The problem is that we need a 3D-object to match eye movements to, but it should actually only have 2 Dimensions - that is, eye movements were recorded along x and y axis, but not z (unfortunately it is not possible to match eye movements to a circle, because the program needs a 3D object). 

Is there a way to do this? I tried setting scale of object Z to 0, but it does not seem possible to set Scale Z of object to 0 for the duration of the complete film scene. And it would take hours to set it to 0 for the duration of the complete scene we're interested in.
You could try to go in edit mode, and then select the vertices you don't mind (press C and then use the circle to select them) and then delete them by pressing X and the option "vertices". Otherwise I think that for make the eye moving you need key-frames. If you selected the option LocRotScale every time you reach the key-frame, it set the location (Loc), the rotation (Rot), and the scale (Scale) of the object to the value it had when you have set the key-frames. So basically you have to delete them, set the Z scale of the object to zero, and re-set the key-frames. To delete the key-frames, select the object, go on the frame on which there is the key-frame, and press Alt-I. Hope helps.