Shadow Catcher problem! Help!

[Seggy]

This is probably a school boy issue here.

I am lighting a shot with a HDRI environment. I want a shadow catcher floor.

I have the shadow catching working use matte tickbox, but the floor surface is visible in the reflections and is blocking visibility of the HDRI and lighting coming from the HDRI in my subject.

See first image has shadow catcher but there is a black reflection of the floor geometry which is catching the shadow.
(green arrow pointing at black floor reflection, diffuse is set to black on the diffuse shader with matte turned on)


Now in this image I hide the floor and you can the the HDRI reflecting properly in all of the car and light is getting to all of the car. I need this, but with the floor shadow... ideally in a single image rather than doing passes etc.



Any ideas folks?

[cleanerxx]

*push*

just ran into the same problem as seggy.

[aoktar]

yes, really need a fix there

[pavel]

This doesn't work in psysical render either. I used compositing tag to disable the floor reflections and only allow the hdri reflections on the car but it doesn't work. It may be from C4D and not Octane?

[dionysiusmarquis]

I think it's because the Object just catches the shadow but does not project the background color onto the object. I already got it working with a background Image and the perspective texture projection on a plane with diffuse material. But then you'll have the problem that the hdri is lightning the projected background image. Don't know if there's a solution right know. But would be very nice to know.

[dionysiusmarquis]

Maybe this helps?:
http://render.otoy.com/forum/viewtopic.php?f=9&t=38911