Black Shadow Catcher Not Appearing Tweet

[shane_rhodes]

I have an interesting (read: maddening) issue with having my shadows appear when it comes time to render. The shadow catcher method works when I do a simple test, but not on the scene I need it for.

Example:

I did a simple test to show what I'm after. Below is a simple sphere on top of a plane with an Octane Sky HDRI mixed with an Octane Octane Daylight.

I have an Octane Object Layer ID on both the Sphere and the Plane. The Sphere is set to 1 (edit: I know the sphere doesn't have an Octane Object ID in that picture, but trust me, I added one) and the Plane is set to 2. I have turned on the Render Layer and checked on black shadows to capture the shadow. Below are the settings:

When I look at my viewer, it shows the results I expect. The sphere with transparency around it and the black shadow with its own transparency around it.

Now, when I try to apply this same method to my actual scene in question, the black shadow refuses to work and I can't seem to find a way to get the shadow to show up. The scene is a Fountain Pen mesh from C4D on top of a map that I designed in After Effects and projected onto a plane in C4D:

In this set up, the lighting, the settings and the Object Layers are the same as in the Sphere test: The fountain pen is set to 1 and the Plane with the projection is set to 2. If anyone knows the solution to this, please enlighten me! Thank you.

Set Up:
Cinema 4D R20.059
Octane 2018.1.3

[bepeg4d]

Hi,
please note that, by default, every object is on ID 1, so it is not necessary to apply an object tag with ID1.
Please, remove all the tags assigned to the pen, maybe you have other tags nested inside the hierarchy.
If not enough, please share the scene with me via PM.
ciao Beppe

[shane_rhodes]

Hi Beppe,

I have tried it both ways. With the tag on the fountain pen and with it off. It seemed to have no difference either way. I'll PM you the C4D file.

[bepeg4d]

So the issue was caused by the plane normal, that was flipped, compared to Camera position.
Switching to -Z has solved the issue:

ciao Beppe