#Bckgrnd color off by 1?
3 messages in this thread
We have been rendering objects for placement on WWW pages (transparent GIFS)
that have a "target" background color of RGB 197,197,197. In order to achieve
this, we have to set the background color to RGB 196,196,196. We have set
gamma correction OFF, dither 256 OFF and ambient light to 0,0,0.
Also, when the gamma correction is toggled ON or OFF the background color value
changes significantly (RGB difference of 24 to 37). We always set it to OFF
before setting the background color.
Are these known problems?
Cal Rodgers
These are no problems… It's simply the way gamma correction works.
Because gamma is the remapping of the linear RGB output to a
nonlinear curve, your RGB values can change radically when
gamma-corrected (especially in the extreme lower-end of the scale).
The 3DS documentation covers this pretty thoroughly, and there's even
a little table of converted RGB values in the 3DS readme.doc that you
can use for comparison (at 2.2).
So, all of the things you mentioned in your first paragraph are
necessary to produce a "locked" target color (except for 000 ambient
light… that has no bearing on the background).
– G
Cal, If you've got Photoshop 3.0 just render your objects with alpha on and
then composite them over a 197,197,197 background in photoshop.
DM