7.12 A note on Image Operators

Image operators (a.k.a. Image-Ops) are a category of effects that cannot compose with each other.

Some kinds of effects such as "Alpha", "Translate", "Rotate", etc. combine with the entire scene that they operate on. For example, if "Rotate" is applied to a scene composed of layers, then each component layer will be rotated by the effect.

We do understand that this is quite a severe limitation for certain kinds of compositions and are working to remove these restrictions.

Some other effects such as "Mask" and "Sepia" cannot combine with arbitrary effects unlike the others mentioned above. This is because they operate on the individual textures that compose the image and ShowTime does not have support for multi-pass rendering as of this writing (Dec 2008). We call these effects image operators or image-ops for short. Image-ops are (or will ultimately be) documented in the effect’s manual page.