Comping into background images

[pgatsky]

Hi all

I've been looking for info on this but haven't quite found exactly what I'm after. There is stuff online for getting backgrounds to work but not like this. I need to be able to hopefully render an object like a bottle into a scene that is already as an image. I know how it needs to be done when doing it just in native C4D with the comp tag etc but I cant seem to find a way to do it with Octane. Id love to try and render the whole scene with Octane but what I need is for my object to have base shadows and ideally be reflected in the floor, even if slightly.

Anybody know how to do this? If so can you please help, thanks....

[pgatsky]

Anybody got any suggestions? I see 7 downloads and 50 views but no replies. Is it just not possible that octane can do this? Hopefully an expert can let me know or put me out of my misery?

[whersmy]

http://www.aoktar.com/octane/OCTANE%20H ... Layer.html

Does this suit your needs? I don`t think it could be that complicated. There is a lot of info if you search for the matte shadow option on the forums I think

[pgatsky]

Hi whersmy. Thanks for your reply.
What im after dealing with isn't just the shadow but thanks. What I need to do is basically have a background image and use that as a base for being able to be reflected into my object and vice versa. With the native comp tag in C4D you can do this by having a background image and a plane or object and using the comp background option in the tag to combine both. I will look into using the layers as maybe that is where the answer is, but I just hoped that someone on here would be able to say that is indeed where I should be looking?

[GIOLETS]

Give a look if this post could help:

viewtopic.php?f=87&t=63808

[pgatsky]

Thanks GIOLETS, looks interesting.

[pgatsky]

Hi all

I've been looking further into this because I still haven't found what I'm looking for

Im attaching another file in the hope that I may get an answer. Being still relatively new to octane some out there may know how to deal with this. I have a scene as shown in the screen shot, and im trying to have the object, in this case a simple cube reflect into the floor and also create shadows. I would also ideally like the floor and background image to reflect back into the cube itself. This I know is possible in c4d using the physical render and the comp tag.

I've also seen after GIOLETS shared a brilliant thread below and have also downloaded the visible background file and script but im not sure if im using it correctly or if it can even do what im after? Would bepeg4d know better?

Really hoping someone can help so thank you in advance.

Lang

[pgatsky]

Hi all
Can anybody shed some light on this one...?
Im not sure if im just getting it all wrong? I get how to make the floor have a shadow using the defuse material and shadow catcher method but what im trying here I just cant seem to get my head around so not sure octane can do it? If I was to do this in C4D native I would apply the same texture to the background and plane and have a comp tag on the plane object with comp background turned on. The texture would be in frontal mode so that any object I place on the plane would reflect onto the floor and vice versa. Is this just not possible in octane? If it is though, which im hoping it is, can somebody point me in the right direction?
Thanks

[GIOLETS]

I am not sure to have fully understood your question.
I have enclosed here an updated file hoping to give a little contribution.

1) In order to extract the Shadows of the cube on the plane you have "enable" passes, I've placed an octanetag on the object that I want to extract shadows giving an appropriate Layer ID.
2) in order to have reflections on the cube and the plane:
-I have modified your light (opacity=0 and not visible on specular)
- please note that around your scene you have nothing so the cube faces reflect only thanks to Visible Background script, but not in physically correct manner. The right choice should be to have a 360° background image all around.

Probably I haven't fully understood your question, in that case, sorry for my OT post.

[bepeg4d]

Luca/GIOLETS is right, you have chosen a very particular scene.
Both surfaces are Glossy without roughness.

Here is what happen if you us a Specular material for the cube:

And here is what happen if you add a Black Primary Environment:

The reflections are controlled by the Border Mode parameter in the Visible environment node:

In Clamp mode, the last pixel of the image is repeated all around, so you are having those reflections, here is what happen in Mirror mode... but as Luca has already sad, better to have a full HDRI as Primary environment.

Finally, here is the reflection pass with Render Layer technique active:

Happy GPU Rendering,