Vector and bitmap files in library

When a raster file is imported into the library is it automatically vectorised? If not then what is the best way to import a file, vectorise it and then store it in the library? Should it be vectorised on the fly or can bitmap images already stored in a catalogue be vectorised in bulk whilst still in the library?
The reason I ask is because I’ve noticed that using anything other than vector files (except maybe for backgrounds) causes rendering problems. For example, I rendered a short movie with drop shadow effects using bitmap files as layer objects and the drop shadows were blocky and shapeless in the final export. Using vector files I have no such problems. A lot of my object and character files were imported bitmap files that were put directly into the library.

It really depends on what you are trying to achieve.

The “import file” and “import and vectorize” are two entirely different import options. There are further tunable parameters in each.

You can import a sequence of images into the same element, for example:
you do not need to import them to the library first.
Use menu-File-import.

Some features of the program work better with vector images because certain actions cannot be performed on a bitmap image. Also, a bitmap is treated as a whole. We do not currently isolate part of a bitmap based on color/shape.

Note also that there are different vectorization option.
Doing a B&W vectorization on solid line art produces vector line shapes. Doing a color vectorization on bitmap images gives a bitmap image with a vector border.

thanks. I’ve simply reimported all my previous files into the library after vectorising them first. Eg Import and vectorise, then drag them into the library, then rename them.