Preamble
We have come to the end of our journey of exploration in the process of creating an effect in Adorage. On the program today, discovering the Overlay step.
For the last time, I advise you, if not already done, to read the tutorials Adorage, first visit, Depth study of Adorage - Video Tab, Depth study of Adorage - Mixer Tab and Depth study of Adorage - Smoke Tab and start this lesson by creating a new effect.
Overlay step
As its name suggests, this tab lets you insert any graphic object, animated or not. If it is animated, it must have been broken down into still images saved beforehand in a directory.
Here is what you see by opening the Overlay tab :
Load a file through the Overlay-graphic zone :
There, against all odds, no additional element was added in the preview window. Because it's not enough to tell Adorage what file to display, but also to indicate how to display it. Indeed you must also load a Clipping mask :
Here, selecting the same file as in Overlay-Graphic gives a magnificent still aircraft :
Sometimes it will be necessary to check Invert graphic to any displayed correctly.
I think at this stage an explanation is needed so that you understand the difference between Overlay-graphic and Clipping mask.
Clipping mask will tell Adorage how the image should be seen as transparent, opaque or semi-transparent where appropriate. This is according to this transparency informations that Overlay-graphic will display.
In the case of our plane, the base image has an alpha channel. Ie an invisible layer in the image that gives the transparency information. This is what the alpha channel looks like :
Black is considered completely opaque and white as totally transparent. This alpha channel is used as Clipping mask revealing exactly the plane in its original shape.
Let's do a little experiment. As Clipping mask we keep that corresponding to the alpha channel of the aircraft and as Overlay-Graphic we load this picture:
That is what we get :
You got it ? 
Continue exploring the Overlay tab.
If you click Motion :
you access the entire settings described in the tutorial Etude approfondie d'Adorage - Onglet Vidéo :
With Covering you determine the overall opacity of the Overlay-graphic object. 0 % = complete transparency, 100 % = complete opacity :
Fade IN and Fade OUT apply a fade in and/or fade out to the Overlay-graphic object :
As I said at the beginning of the tutorial you can also display animated objects, or rather a sequence of images. For this, instead of loading a file in Overlay-graphic and Clipping mask you just specify a directory. The directory in which is the series of image :
Here again, the small plane, but this time in an animated version :
With the Running menu :
you indicate how the animation should be played. For example, with a 5 images animation numbered from 1 to 5 :
- Play forward displays 1-2-3-4-5
- Play backwards displays 5-4-3-2-1
- Play ping-pong displays 1-2-3-4-5-5-4-3-2-1
- Play pong-ping displays 5-4-3-2-1-1-2-3-4-5
The Running box determines how many times the sequence described in the Running menu must be reproduced :
For example, Running box on 2 and Running menu on Play backwards gives : 5-4-3-2-1-5-4-3-2-1.
Conclusion
Well, this time it's the end !
We have well and truly reached the end of our journey. Some points (minimum) have been deliberately left out. It is not for the sake of economy of explanation, it's just because I have yet to understand what purpose they served. To my discharge, it is clear that manual Adorage is also unclear on these points a night without moon! 
It promised, I shall not fail to return it and complete this series of tutorial if I find out more. From your part, please don't hesitate to warn me if you know more. 
Bonus
For those who want training to reproduce the first video of the first tutorial in this series, we put at your disposal in our special download area the file TutosAdorage.zip including all the elements necessary to achieve the effect.
What ? What do I hear ? It sounds difficult for you ?
No ! If I succeeded, why not you? 