Camera Projection - Nuke 101: Professional Compositing and Visual Effects - page 468

The good thing about your tree is that each geometry has its own pipe coming
from the texture. This gives you the option to tweak the texture of each geometry
separately.
2. View RotoPaint1.
Use the RotoPaint node to clone some texture where you're missing it.
3. In RotoPaint1, select the Clone tool.
4. Using the Tool Settings bar, make sure you're painting on all the frames.
5. At the top of RotoPaint1's Properties panel, uncheck the Rgba.alpha so you don't
paint in it ( FIGURE 11.19 ) .