View Full Version : Hilites in Eyes not Symmetrical

Tom Wood
09-30-2003, 02:42 PM
Hi All,

I've tried various settings to fix this, but I can't seem to find the answer. I've been very careful to use the numeric entry pads to place the object and the camera on the same line. The eyeball objects are offset from the origin by the exact same amount. Only one light affects specularity. But the hilites that show up in the eyes are not in the same location on both eyeballs. What am I missing?



09-30-2003, 03:07 PM
I don't think the highlights would be symmetric. Objects at different points in space will have different incident angles with the light. I think if you move the light futher back the highlights will be more symmetric.

09-30-2003, 03:09 PM
Maybe Im a bit confused too ..

If you have one light affecting those eyeballs in the scene the specular highlight won't be the same on each eye due to the position of the light in relation to the position of the object.

I don't know why you would want this anyways - but you could always use 2 lights with the same offset and selectively light each eyeball.

Tom Wood
09-30-2003, 04:47 PM
Got it, or at least getting close.

Two lights with some odd offsets. I suppose there's a way to use geometry (trig?) to calculate the proper offset based on the relative offsets of the camera, lights and object, but I did it with trial and error.

I know the other picture may be more 'realistic' based on the physics of the setting, but since the character eyes dominate the scene, it just looks better this way. To me.

Thanks guys.


09-30-2003, 06:00 PM
How far away if your light from the eyes? My guess is that if it is say 30 feet away or more you willl not see any offset what-so-ever. Howevere if you light in a less than ten feet or with in a foot or two you will always see the difference.


09-30-2003, 06:12 PM
Nope actullay you will never have the high light in the same place.

Think of it this way - if they were pool balls and you wanted to hit each one into a pocket of a pool table you would have to hit each one in a different spot to make it - as they are in diffent locations on the table. So to the angle of the light to the camera is different - it is reall life.

clear as mud?


Tom Wood
09-30-2003, 06:20 PM
Yeah, I tried backing the light off several meters, and it didn't have any effect. You have to keep adjusting the X and Y to keep the highlite on the eye, so the relative angle never really changes, even as you back away. Distance light, spotlight, all the same.

If you haven't tried it, using the 'light' view through a spotlight to point it at something precise is a cool tool. In 'rotate' then reduce the cone angle to like 0.5 and you can point the light right at the pupil, then open it back up to cover the object.


Having fun now!

09-30-2003, 06:36 PM
You can also have the light target the eyes where ever you move it.

Look under "motion options" and pick the target items to be your eyes.

Heres looking at you.


09-30-2003, 06:50 PM
40 min - LW and Photoshop - yes fun - now back to work.