The best plugin I know to composite a scene is Psd Manager: it compose automatically in layer for Photoshop and it works very well!
But Compositing is the most powerful technique for manipulating images in computer graphics is it could be fine to understand a little bit better what Psd Magaer do automatically.
However, in architectural rendering not many people use this technique. Infact, there are not many articles on the web and – anyway – you can render and render again still images 100 times, this will not a incredible problem (With the animation that would be impossible!!)
Anyway, compositing technique allow us to save our time so we can add the compositing to our list How to reduce the rendering time!
A few days ago I read an article explaining a very basic compositing, just to see how it works: the article is comping of Basic Vray Renders, Then I start from there to present the topic: a small compositing tutorial!
I don’t want to bore you with words-words-words and I hope the following image and a psd file will clarify the matter in a few seconds:
I can choose to render only “certain parts of the scene” for example, direct light, the reflections or shadows. Overlap then – with different fusion methods (multiply, screen etc. ..) – all these images using compositing softwares such as Shake, Combustion, Fusion .. or simply Photoshop.
The result will be (almost) the same image! The difference? Control.
Yes, because having all the separate channels we can choose whether to have more or less global light, manipulate the reflections, reduce or fix some color, simply adjusting on its channels. So you can manipulate the image with a great facility.
Download the PSD file below see with your eyes how to control everything.