Get around the problem of EEVEE’s lack of shadows/reflection catcher, and finally get your models to be much more realistically integrated with your HDRI environment. Also results in correct alpha channels for compositing over a different background in comp
Can I save the alpha for compositing in another sofware?
Yes, set the film to transparent in the render settings and save as an alpha supporting format such as .png.
Can I have just shadows?
Can I have just reflections?
Yes, by turning off the shadows on the lights
Does it work without a hdri?
Yes, set a solid colour in the world shader editor:
A short tutorial on how it works can be found here: https://youtu.be/BYtDJLCFdw4
the download includes two scenes, one which contains the material and world for linking or appending into your own .blend file, and the other is the example file from the above video just for fun: