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How to track eyeline/line of sight/directional space

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Magnus Wolff SoerlieHow to track eyeline/line of sight/directional space
by on Sep 9, 2014 at 8:49:56 pm

Hi guys!
Been reading and harvesting knowledge from here for a long time, and hope you can help me with an issue.

I've searched to death, but don't know the term (tracking eyeline, eye motion, eyesight, etc.,etc.).
I've also watched a ton of tutorials, have no problems with motion tracking/eye replacement/grading etc., but I've never seen anyone take this 3D-element of tracking into consideration.

I basically want to track the eyeline, where the eyes are seeing, and I'd like to be able to apply the data to a null and reuse it as much as needed. Not just for eyes, but anything direction, like streetlights, headlamps etc., and take both object and camera rotation in space into consideration. Kinda like a cone sticking out, y'know, like in Jurassic Park :

How do you harvest the data, and tell AE which plane is which?

I've just placed the grids on now to illustrate direction, because the tracking is horrible, and the keyframes keeps interpolating. I am prepared to do this frame by frame, but hope you have some clever suggestions.

Hope anyone got a method for this!

- Magnus

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Derek BoettcherRe: How to track eyeline/line of sight/directional space
by on Sep 12, 2014 at 11:59:59 pm

Though I haven't tried it, so I couldn't tell you exactly if it would work, have you tried applying the positioning data to the anchor point? That would move the anchor point around, in theory sort of simulating the eyeline. You would need to make your null a 3d object and apply any z data to it too; since moving the anchor point will move the null in the opposite direction, also activate the expressions and add *-1 at the end. I'd also track it with the rotation to try and mimic the full range of motion. Don't know if that would work, send me a message back if you try it.

Derek Boettcher
Creative Management
BTH Media Group

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