Shadow catcher issue

[emote.agency]

Greetings. I have 2 issues connected with shadow catcher.

1. Why do I get strange shadow like this?

1st image - flat render with background. Normal shadow.

With background

2nd image - alpha render added on a solid in Photoshop. Shadow is awful.

PNG with shadow catcher

2. Why I can't apply material with shadow catcher to an extruded spline surface. Even when I turn current state to an object - it just disappears in render with applied shadow catcher.

[frankmci]

Check the surface normals on your extruded spline surface. You are probably looking at the back side. I run into this all the time on extruded seamless cyc objects.

[emote.agency]

Polygons really were inverted, but still nothing has changed

[Secretwoodsrl]

I think shadow catcher is bugged (or just so limited) and I never obtain something useful with it (since Octane 2018).
Shadows are really dark and with infinite lenght if you use area lights. Also it doesn't work with denoiser.
This is a problem of the core of Octane (not the plugin) but they never worked on it.
If you can try to avoid it and use layers.

[emote.agency]

Yes, I also think so. And it's strange to me, why this feature exists if its buggy. Of course I can draw shadow manually in Photoshop, but it will take more time and it won't be as realistic as Octane makes it so.
I find DayLight for me the most preferred light, maybe it's the reason of such shadows. And still, if it's buggy only for such kind of light, why it isn't solved yet.