Overlay canvases are canvases that are only visible from a particular viewpoint. They are used in the perspective window to create perspective texture projections, 2D roughs, or for annotation purposes (to create bookmarks).
You can grab a screen shot of a work in progress, and use the 2D image as a basis for further painting. The painted image can either be used for presentation of rough concepts, or you can project that painting back on to the model as a texture, and see it in 3D.
Transparent planes can be used to annotate a model. The annotations are associated with the particular viewpoint, so you can be sure they are seen in their proper context.
The viewpoint is accessible through one of the following methods:
To create a new overlay plane, choose Canvas > New Overlay Canvas. The options are almost identical to Canvas > New Canvas .
Choose a standard paper size (default is A4) to print on, or choose one of the following:
Custom – Lets youspecify the dimensions of the overlay canvas in world size units (mm or in).
User defined – Lets you specify the dimensions of the overlay canvas in pixels only. The default values are 1900 by 1200 and can be changed in the Paint section of Preferences > General Preferences .
Fit to screen – Lets you specify the dimensions of the overlay canvas in pixels only. The default values correspond to the current size of the window.