Shadow catcher, possible ? Oo

[anonymous_user_b81f854c]

I highly recommend you take a look at the new Composure sample in the Epic Launcher. There is an example of a shadow catcher setup in there using proper lights. It is using the composure plugin but I also helped another person set up a shadowcatcher a few days ago without composure.

The gist of the more ‘robust’ way to do this is to instead use a white flood mesh and set that mesh to be only visible to a Scene Capture. he scene capture can be pointed down at the ground orthographically. Then you set any shadow casters to ‘cast hidden shadow’. Then you can hide them and the shadow will render onto the white shadow catcher ground.

The trick is making the shadow catcher ground not render in the main view. Technically it should be possible via the ‘owner only see’ flag, but that wasn’t working recently. So instead I just did something a bit hacky that checked if the camera vector was straight down (ie dot(CameraVector, 0,01) and check abs value), and collapsed the shadowcatcher in the vertex shader by adding negative worldposition.

Its also possible to handle that visibility problem more gracefully by manually hiding the shadow catcher every frame, then unhiding it just before the scene capture updates and then re-hiding it.

Can you go into detail with any of these, ? I tried doing the owner only see, but then it hid the shadow too.