2D Tracking - Nuke 101: Professional Compositing and Visual Effects - page 232

you are viewing, creating a kind of feedback. This is why it is im-
portant to view the preceding node—Premult1.
3. MovethefourFrompins(from1,from2,from3,andfrom4)totheedgeoftheim-
age. It's easier to do while viewing the alpha channel.
4. ViewCornerPin2d1'soutputintheViewer(makesureyouareviewingRGB)and
switch back to the CornerPin2D tab in CornerPin2D1's Properties panel.
You can see here that the To points are sitting on the edges of the image, which is
what you were after ( FIGURE 5.29 ).
Figure 5.29. Adjusting the From pins made the To pins move to the correct
place.
You need to now place the new, moving image on top of the frame background.