Shadow Catcher Hacks: What's best to try?


(Tod Adkins) #1

Right now I'm trying to get a shadow catcher like effect on an animated scene. Please pardon the horrible test scene. I'm not new to 3D but very new to real time work and just learning. :wink:

The way I'm hacking at this is to use an emitting surface that is the same color as my background as a floor plane, but with no color, and then cranking up some of the screen based ambient occlusion (SSAO).

That's obviously far from perfect as it means that I have SSAO kind of going over kill on my other items AND if I apply bloom (esp on white background/floor) I get bloom everywhere. Dreamy but not what I want. :wink:

What's the best way to fake it? Use some geo with some maps on it? That wouldn't change though with my geo as it moved. Is there some old school game way to flatten out a copy of the mesh on the Y axis, and use that as a shadow or something?

Thanks!
Tod


#2

Hi Tod,

We have realtime shadows, can't you just enable shadows and they will be cast on a floor plane?


(Tod Adkins) #3

I could, but I also want my floor to be a constant color- not lit OR to just show the background through it but...catch shadows. :wink:


(Shaderbytes) #4

For the floor plane let it have its own material , then reduce spec to 0 and set roughness to maximum... This also helps but in the end there is no good solution that works in all scenes you will just have to make peace with that for now :slight_smile:


(Tod Adkins) #5

Yeah, my hack was only working for a white floor and room scenario. Anything else and it failed. Good to know where the limitations are so I appreciate you guys letting me know.

I'm sure I'm not the first person to try and work around that there is no shadow catcher! :wink: