make shadow on (hdri) image background

[rappet]

Hi,
Maybe this is talked about in other posts already..
I found something about a shadow catcher material for the wishlist,
and I know I can make two renders and make it happen in postproduction (PP)...
..but does someone has a brilliant way to make this shadow on the background with just one rendering (without PP),
maybe by doing something with the material?
In my example I added a plan object to make the shadows, and this can work,
but this will not always be satisfying to get the right result.

greetz,

[vinz]

+1000
i asking for a "catch shadow material" and a "border rendering" feature since a long time...
but nothing is in the plan.
we will see...
the only way i know to do it now, is to use PP and making your own shadow layer.