Guys, PLEASE help :-)

[qalunaq]

]ok, maybe i didnt said it right

if you can make a shadow catcher that would be great for layers

but in my second post above, i was talking about final render in octane (compositing) for the gain of GI/reflections/caustics interaction with the projection.

If you could implement this too beside a shadow catcher, it would be great. What would give GI/raytracing interaction from/to the (camera)projected BG image.
Wait i make a drawing.

[ROUBAL]

+1 : I asked for Shadow Catcher materials many times since the very beginning of Octane.

Currently, when I want to composite with shadow with an other image in background, I use the Clay render mode. The Daylight system casts shadows visible in clay mode. I remove the sky color from the rendered image to get a greyscale image (the sky color is already present in the color render ), and I use the image as a layer in Multiply mode in Photoshop. I adjust the strength of shadows with the transparency slider.

I also would like the ability of disabling shadow casting for any material (just a button in the material parameters). This would be very useful to avoid a cylindrical or spherical environment to block the light from the Daylight system or HDR environment, allowing for background the use of images mapped on planes, spheres or cylinders for far mountains or buildings, or even skies.

One thing that would also be imho very useful for compositing, would be the ability of displaying in Octane an image (obviously of same resolution ration X/Y as the render settings) in background in the render window, when using the alpha mode. It would allow to help for the placement of the foreground rendered objects when they are intended to be composited with a background image. The background image hasn't to be actually rendered in Octane, as the final image will be made in an image editor.