Compositing Hi-Res Stereo Images - Nuke 101: Professional Compositing and Visual Effects - page 363

You now have a single Read node in the DAG: Read3. If you look at it carefully,
youcanseethereisalittlegreeniconwithaVinitatthetop-leftcorner( FIGURE
8.32 ) . This indicates that this node has multi-views. Let's see this in the Viewer.
Figure 8.32. The green V icon indicates a multi-view node.
4. Look at the newly created Read3 in the Viewer.
5. Go to frame 50 in the Timebar.
6. Switch between viewing the Left and Right views using the Viewer buttons.
You can see the difference between the two eyes. This bullet is coming right at
you. You can see more of its left side on the right of the screen with the left eye,
and more of its right side on the left of the screen with the right eye. (Take a pen
and hold it close to your face and shut each eye and you can see what I mean.)
7. View the alpha channel in the Viewer, then switch back to the RGB channels.
Notice there is an alpha channel here.
Having an alpha channel affects some of what you are doing here. As a rule, you
shouldn'tcolorcorrectpremultipliedimageswithoutunpremultiplyingthemfirst.
Having an alpha channel is supposed to raise the question of whether this is a
premultiplied image. You can see in the Viewer that all areas that are black in the
alpha are also black in the RGB. Black indicates that this indeed is a premulti-
plied image. Just to make sure, I asked the 3D artist who made this to render out
premultiplied images, so I know for a fact that's what they are.
Applying color management on Read3 applies color correction on the image. Be-
cause it is premultiplied, you need to unpremult it first. To do that, use the Prem-
ultiplied check box next to the Colorspace property ( FIGURE 8.33 ) in the Read