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View Full Version : Alpha transparency: restoring gleam?: AE



jeric_synergy
05-02-2012, 05:24 PM
See JPG.
LEFT IMAGE
On the left is a LW rendering on black, with the alpha ignored. On the right is the same rendering with the alpha interpreted as straight. Same file, on a grey background.
RIGHT IMAGE
The same thing, but with the straight layer duplicated 49 times and blended with "Lighten".

As you can see, the straight interpretation is very boring, and I'm trying to restore the highlights and glints of the "ignore" render. But, duplicating a layer 49 times seems ridiculous. Is there a better way to approach this?

I'd also like to restore the saturation of the original render.

Thanks.

nickdigital
05-02-2012, 05:40 PM
What about adjusting the Alpha Levels?

jeric_synergy
05-02-2012, 08:06 PM
What about adjusting the Alpha Levels?
At some point I figured I'll have to do that. (Fortunately, IIRC I saved a boatload of buffers out, but I'm equally ignorant about that, so......)

I miss cinematography & gaffing: photons haven't been upgraded in billions of years. (OTOH, LightWave doesn't insist you get up at 4:00AM to catch the sunrise.) :hey:

raw-m
05-03-2012, 03:49 AM
In LW, Surface Editor/Advanced, try setting the alpha channel to Constant Value and enter 255 for the value on your transparent surface. Not for all situations but is quite handy. Other than that, as nick digital says, use Curves in AE and play around with the alpha channel.

jeric_synergy
05-03-2012, 08:34 AM
Tnx, everybody. Some more parameters, which of course complicate things:

1) When the final comp comes around (34 hours left on the render), I want a gradated or textured image compd behind this geometry, which of course means I'll want to have some transparency so I can see the objects are 'glass'. So, I'll need an alpha<255.

2) One of my main concerns will be to restore the gleams on the moving pieces.

3) Is the "shaded refraction" buffer a vector quantity?

Mr Rid
05-09-2012, 10:55 PM
What if u just use the luminance channel as a mask to preserve the highlights and color?

dwburman
05-09-2012, 11:11 PM
I'm pretty sure this won't work, but does it look the same when you render to an HDR format (.exr, .rpf, etc) and put AE into 16 or 32-bit mode?

Mr Rid
05-10-2012, 01:17 AM
...does it look the same when you render to an HDR format (.exr, .rpf, etc) and put AE into 16 or 32-bit mode?

Or vice versa. I sometimes find that a 16/32 bit element will comp more desirably when converted to 8-bit. Also have to watch out when you may be unknowingly comping elements with different depths and one may be converting to the other after a merge.