How to don´t receive the shadow or the Illumination of a near object, with a enabled shadow?

[ruvio_gaetano]

Hallo dear V-Ray community.

I have a Vertex Surfaces and I need that these surfaces don´t detect the shadow or the illumination of the surrounding area, because I need to not alter the colors.
To do this, I disabled the Shadow opt. (per example of the Dome Light) set the raytrace properties and disable the cast shadow option of the surrounding area material.
with this step I succeed in the intent but at the end, I will have a flat rendering like this.


Any advice on how to maintein clean (the surfaces with the Vertex color), and at the same time, be able too enable the shadows, to give more depth and realism to the rendering?

[Zahari.Ivanov]

Hello ruvio_gaetano

Thank you for your question. I would like to ask for some more clarification or perhaps for you to explain this in a bit more detail, mainly what the end goal is. If you have any images that can better illustrate what the final render should look like, please send them over to me as a personal message.
With us having a better idea on what needs to be achieved, we can look for any potential workflows to provide you with, or to suggest specific adjustments that you can make to your settings.

Thank you in advance!

[ruvio_gaetano]

Thanks for the interest Zahari.Ivanov.
This could be a good example.
In the attached image, the shadow altered the vertex color in comparison with is legend.
I send a private message with files to facility the workflow.
Best regards

[konstantin_chaos]

Hi ruvio_gaetano,

I believe your best option is to apply a self illuminated material to the ground geometry.
If the heatmap is a texture then just apply the texture to the emission color of the material.
You might also want to override the effect of the material for the Global Illumination, Reflections, etc.

Here are the steps to achieve this:

1. Create a new Emisive material and apply it to the ground
2. Add the heatmap to the Color slot of the material
3. Add Override attribute to the material
4. Create another new Generic material - this one will be used for the ground override...
5. In the Override attribute of the Emissive material - select the Generic material in the GI dropdown menu.
   This ensures that the material will not emit light onto the walls and surrounding objects.

I've also attached a scene with the setup.

Hope that helps.

Regards,
Konstantin