Bentley Descartes offers many useful functionalities that ease the task of working with raster data.
The dynamic binary raster snap functionality allows the user to snap inside or at the border of a linear feature (e.g. : line, circle, curve, etc...).
Performance tip : Setting the correct maximum line width will ensure that the snapping works optimally.
Bentley Descartes currently supports three different kinds of binary raster snap mode.
Snap inside a raster line, whatever is form or length.
Snap at the border of a raster line, whatever is form or length.
Snap at the intersection of a raster line.
Note that both the intersection snap and line snap can be activated at the same time.
The raster pixel grid option leads to the display of a grid representing the boundaries of pixels in an image. The distance between two lines of the grid is determined by pixel's size. For example, if the pixel's size is 1 meter, than the distance between two lines will be 1 meter.
The raster pixel grip option can be activated in the Descartes' preference pane.
Note that the pixel grid is displayed only at a certain zoom factor to ensure that the raster is still visible throughout the pixel grid. Below is an example of the same image region, the left picture being at a zoom factor less (i.e. : farther from the image) than the right picture.
A raster save set is a list of binary raster files with some of their respective attachment options. The raster save set is saved in a .rst file, which is created from the list of selected raster by clicking on the menu shown below.
Once a .rst file has been created, it is possible to import the raster save set in, for example, another .dgn file (see the import menu item in the picture above).
The attachment options saved for each raster in the raster save set are :