How to render a model with transparent background but with its shadow?

I have no experience with compositing in Blender. So i probably have a very simple question for you guys

I have made a product box for a client. Set up on a white backgroun with and HDRI for lighting. Its give a nice shadow on the floor.

However, the client wants me to also deliver this image…but then without the backroung and floor. So completely transparent. But with the shadows. So they can composite it themselfs onto different backdrops and stuff.

So my question is… How would I render this image so I only have the model and the shadows that its castings?

Search for “shadow catcher” on Cycles

EDIT : On the object who will receive the shadow, on the properties panel, go on “Object” > “Cycles settings” > “Shadow Catcher”. After that, on “Render”, don’t forget to set a transparent background. You don’t even need to use the node compositing for that.

https://wiki.blender.org/wiki/Dev:Ref/Release_Notes/2.79/Cycles#Shadow_Catcher

1 Like

That was exactly what I am looking for. Thank you!

Solved…