There is a convenient opportunity in the Cycles render engine to render an object with shadows on a transparent background using material with the “shadow catcher” option. There is no such material in EEVEE render engine, however, in EEVEE we can make our own “shadow catcher” based only on nodes.
To increase the speed and convenience of working with the “Pie Menu” in Blender you can use its “autoclick” option. To use it press the desired “Pie Menu” call keys, don’t release them, move the mouse cursor in the direction of the desired item, and only then release the buttons on the keyboard. You don’t need to click on a menu item, the choice is made automatically.
In Blender 2.8, the displacement node in Cycles render-engine was changed from scalar to vector. If you simply connect a black and white height map to the Displace input of the material output node, like in Blender 2.7, it will not give the desired result.
To make the correct node displacement in Blender 2.8 add “CombineXYZ” and “VectorDisplacement” nodes to the material node tree. Connect the height map to the “Y” input of the “CombineXYZ” node and its “Vector” output to the “Vector” input of the “VectorDisplacement” node. After that, connect the “Displacement” output of the “VectorDisplacement” node to the “Displacement” input of the material output node.
When we create a field on the add-on interface panel, the value of which changes something in the node tree, each time the user changes the field value the node tree recompiles. If the user changes the value in that field by holding and moving the mouse, too frequent node tree recompilation will cause Blender to hangs.
This problem can be solved using decorators for deferred updating of the node tree.