Object
Here you can place the object onto which the deformer should project. This object must consist of polygons, or generate such. Splines, for example, do not work.
Define here whether you want to project in a constant object axis direction to be defined (Parallel) or in the direction of a spherical surface that is formed with the origin of the projection deformer as the center (Directional).
The deformer position therefore has no influence with Parallel (but does with Directional). The opposite is true for the deformer angle: Parallel is based on the object axis direction, while Directional takes the object axis position into account.
If you've defined Parallel as the Projection Mode, you can define the deformer axis in whose direction the projection is to take place.
If you want the subordinate hierarchy of the object placed at the Target Object to serve as a projection surface as well, activate this option. Otherwise, only the linked object itself is actually used.
If Strength is set to 100%, projection will be made directly onto the target object. For various reasons (e.g., prevention of penetrations) it may be useful to leave some distance to the Target Object. This can be done using Offset. Positive values calculate the distance in front of the target surface in projection direction, negative values behind.
This specifies the strength of the projection between 0% (no projection) and 100% (full projection).