multipass - shadows

Corona Corona for Cinema 4D Issues
1

hi there,

not the latest
is this the way it is supposed to look?
is there currently any other way to obtain a clean shadow pass that one can use for some compositing, that is incorporating some cgi into a foto?

thanks for any lines in regard to this

c4d_corona_multipass_shadow.JPG
c4d_corona_multipass_shadow.JPG1777×1258 222 KB

2

The set up may differ depending on what you want to do

  • Composite within C4D
    CoronaLight material with Emit light off and your backplate loaded
    Load this into Direct visibility override in the Environment overrides Scene environment tab in the Render Settings, and set to Frontal mapping
    Load the same backplate into the Shadowcatcher in Backplate mode, set to Alpha of Always solid
    Then when you render, the shadows (and reflectings, and GI light bounces from the objects) will be composited directly onto your backplate

(sorry for the sample image, didn’t have time to align the cube to look good on the backplate!)

More to follow…

Compositing 01.jpg
Compositing 01.jpg1914×1038 225 KB

3

For using a shadowpass instead, see https://corona-renderer.com/wiki/render_elements

I’m not so familiar with using this in compositing, so someone might be able to give further information :smiley:

The shadowpass is the complement of the beauty pass (when added linearly to the beauty pass, it negates the shadows). This means you could subtract it from an unmodified version of your background in order to add shadows. Depending on use, you could use any material on the plane, just so long as it has shadows on it, doesn’t have to be the shadowcatcher.

Do note that the shadowpass is affected by tone mapping.

4

For the Shadowcatcher, things should work the same as in Max, so the tutorials at

should apply.

There are some current known issues - for example, a CoronaBitmap shows upside down when used as a backplate in the Shadowcatcher. Also, while looking into your request, I noticed this possible bug (in Max, as well as C4D) for surfaces that are at right angles to the Corona Sun and possibly other light sources - [https://forum.corona-renderer.com/ Shadowpass - surface at right angles to Corona Sun is non-black, bug? ](https://forum.corona-renderer.com/ Shadowpass - surface at right angles to Corona Sun is non-black, bug? )

If the info here doesn’t help, could you share more specifics on what you want to achieve - e.g. compositing done directly in C4D with the end render being the result, or rendering for compositing later in another program, and is that compositing simply a matter of overlaying objects on stills, and so on. Also, some screen grabs of your scene set up and materials would be useful too!

Thanks!
Tom

5

This might be a coincidence, but maybe it’s fate.
Not long ago, when I tried he shadow catcher and I used the same setup and maps for that.

Not to wander off-topic… Follow Tom’s guide!

piggy.jpg
piggy.jpg1280×720 310 KB