View Full Version : COMPOSITORS HELP - How to get better alpha chanels in Lightwave?

03-16-2014, 06:55 AM
Alpha channels in Ligtwave ( also in 3d max ) are not good. We get a halo around image. We need to apply mate choker on compositing softwares to solve and sometimes, specially when there's hair and fur involved, it cuts too much. This halo is bigger in floating point format kinda exr. Motion blur get's a horrible alpha. What have you done to solve this?

03-16-2014, 07:48 AM
Which compositing application are you using? I find that, it I render passes on black, there's no problem in Fusion.


03-16-2014, 09:17 AM
Always render out of LW with straight/unmatted alpha, never had a problem that way.

03-18-2014, 06:46 PM
I need to recheck again but i have seen black outline problem on AA too in lw11.x
(I'm fusioning too)
So now, sometimes, if i do not need background, i render in straight... That was not the case before... (lw9.6)
I must dig again to be sure about ... something have changed...

03-18-2014, 08:02 PM
Check these:

1) Make sure your alpha channel is rendered in linear color space.
2) Make your comp app is reading the alpha as linear.
3) If color correcting, make sure you only color correct the RGB and NOT Alpha channel.

If just one of the steps above is followed incorrectly, you will get bad matte lines.