Source-target Settings
Bake shading on the surface of selected objects to the active object. The rays are cast from the low-poly object inwards towards the high-poly object. For more info regarding Source to Target bake, read Selected to Active Render Baking in the Blender Manual.
Choosing a source object
To choose a source object, it should be added to the List of Objects. Follow the steps:
Add both low and high-poly models to the List of Objects
Select the low-poly in the List
Expand the Item Settings panel
Expand the Source to Target panel
Check “Target”; set “Source” to be the high-poly.
Ray Casting Settings
Source-target Panel includes more settings, configuring which may improve baking results:
Extrusion
Max Ray Distance
Cage object