Is it or should it be possible to use a texture for a matte wrapper material?

[Micha]

Hi,

I tried to get a textured ground where the shadows control the visibility of the textured ground. Is this possible?

-Micha

[georgi.georgiev]

With the Matte option enabled, the background will always be visible when viewed directly from the camera and the base material will be used for GI.

Nevertheless, could you please elaborate exactly what you are trying to achieve?

[Micha]

I tried to see the texture of the base material in the shadows like a soft cut out from a photo. Attached a raw simplified scene - at the viewport the colored texture shows the texture of the base material and I expect to see it in the shadows.

[Peter.Chaushev]

You won't be able to achieve this solely in V-Ray. Some image compositing would be required. A possible solution is to do a couple of renders:
1. Do a render using MtlWrapper with disabled Matte option and Generate GI set to 0. This way the base material will be visible without affecting the rest of your model.
2. Do a second render with MtlWrapper's Matte option enabled, Generate GI remaining at 0 and make sure a Shadows render element is added.
3. Use image-editing software of your choice to mix both render outputs by using the Shadows channel output as a mask.

Hope I've correctly understood what you are trying to achieve.

Kind regards,
Peter

[Micha]

Hi Peter,

thank you for the suggestion. I ask me, couldn't a direct way implemented? See it as a wish. Attached an example during the calculation jumps from the LC prepass to final pass. Here you see both, the texture and the final shadow. I expected to see the green grid texture and the alpha is controlled by the shadow. Could this be implemented? I miss a "show base material" option.

Best-
Micha

[Peter.Chaushev]

Implementing a new MtlWrapper feature solely for this effect would not be feasible when there is a simple compositing alternative solution.
This is the first request of this kind as far as I know. If there are more similar requests in the future, the decision will be reevaluated.

Kind regards,
Peter

[Micha]

I understand. One more thought. Maybe the "control by shadow" could be implement like texdirt as a texture type - texshadow.