Reflection on black floor

[Lubo]

Hello,
wondering how to get a visible reflection on a pure black floor. I need a pure black studio for an product animation and I use the 4DM-Seamless - Floor, which works very well, but even not with a black colored floor. How would be your workflow to create something simular?

Thank you.

Best regards

LD

[bepeg4d]

Hi,
have you tried with Render Layer passes?
http://www.aoktar.com/octane/RenderLayer.html
ciao Beppe

[Lubo]

Hi Beppe,
thanks for reply. Yes, but that way I have to "create" my floor and background in the post production and all the other stuff like the shining of the lights on the floor. That´s too much work for that particular project.
I`ve recreate the scene with set the default enviroment to black and give my Floor-Disc a opacitiy. Please take a look at the screenshots. How can I increase the sample rate of the reflection and the passes it looks so noisy and splushy? An why do I see my Floor-Disc slightly in the "Render layer mask"-Pass? It has a different Object ID.

Thank you

[Lubo]

And here is the example file

[niestudio]

You only have 150 samples currently set. Did you try increasing it to get rid of the reflection noise? Also look into adaptive sampling as it will render the main boxes and then focus the work on the reflection.
As for the mask, yes you have set them with different object IDs, but you have not enabled render layer or reflections in the render settings

[Lubo]

I´ve raised up the values but still have the noise in the floor reflections. The splushes were killed by higher Denoiser values (Min. denoiser samples 100, Denoise interval 50)

[Studio21]

how about using light linking? exlude all lights from the floor object?

[milanm]

Noise is caused by Opacity and Path term. parameter.

1. Instead of using a Gradient in Opacity, use it in Specular.
2. Lower Path term.(ination) parameter to 0.
3. If you need to composite your renders in post, use Render Layers instead of masks.
4. Use: Render Passes/Info Passes/Max samples to set the quality of your Render Layer Masks ( but it looks like they are limited to ~256 )

Also, please keep in mind that denoising is not going to work correctly on renders with alpha channels, ID masks etc. This is NOT a bug, it's just how the world works, sure you can try and you might have some success... if you can get away with artifacts.

Here is the render with 64 samples denoised.

Bonus tip:
For cleaner renders (esp. when Opacity is involved) keep your Max Samples number to a multiple of 2, i.e. 32, 64, 128, 256, 512 etc.

Cheers
Milan

[Lubo]

Great Tips. Works fine. Thank you very much!!

Best regards

[Lubo]

Another question. How would you control the falloff of the Reflection on the floor. I use the C4D Gradient but it`s not smooth enough or the transitions not fine enough. Is it better to you use the "image texture" and the Octane Gradient? Or is it possible to increase the solution of the c4d gradient?

Thanks