Map a gradient to a falloff?

[jskt]

I'm trying to make an irridescent material. The way I would have done this in VRay for Max would have been to make a Gradient Ramp map with my spectrum, put it in "mapped" mode, and assign a black/white Falloff as the map.

However, the Gradient in VRay for Rhino doesn't appear to have a "Mapped" mode, so this approach appears to be a dead end.

The thin film interference OSL shader is out too, since I can't load OSL shaders in VRay for Rhino (right?)

What's the best way to approach this? I'm sort of getting there with a falloff between two noise maps with 4 spectral colors with coordinates set to Spherical Environment, but I don't think that's going to work in every case, as the colors won't actually change by angle.

Furthermore, Mapped mode for gradients is enormously useful in all sorts of material editing situations, as it's an end run around the limitations of any map with only two or three swatches. Any possibility of adding this to the built-in Gradient map, or is there a setup that replicates this functionality?

[Peter.Chaushev]

Hello, and apologies for the late reply!
There is currently no way to achieve this in 3.60.02.
Our dev team is scheduled to work on an implementation allowing this exact functionality for V-Ray Next for Rhino.

Kind regards,
Peter

[konstantin_chaos]

I'm trying to make an irridescent material. The way I would have done this in VRay for Max would have been to make a Gradient Ramp map with my spectrum, put it in "mapped" mode, and assign a black/white Falloff as the map.

However, the Gradient in VRay for Rhino doesn't appear to have a "Mapped" mode, so this approach appears to be a dead end.

The thin film interference OSL shader is out too, since I can't load OSL shaders in VRay for Rhino (right?)

What's the best way to approach this? I'm sort of getting there with a falloff between two noise maps with 4 spectral colors with coordinates set to Spherical Environment, but I don't think that's going to work in every case, as the colors won't actually change by angle.

Furthermore, Mapped mode for gradients is enormously useful in all sorts of material editing situations, as it's an end run around the limitations of any map with only two or three swatches. Any possibility of adding this to the built-in Gradient map, or is there a setup that replicates this functionality?

Hi jskt,

Even though the setup you've described is not currently possible through the UI (as Peter pointed out), it can still be done by manually editing the .vrmat file.
Unfortunately it's not a trivial task and you have to be familiar with the internal V-Ray shader structure in order to make it work.
Here's and example file that should behave the way you want:
Gradient_Falloff_1.zip
Once you load this file you'll see that the Diffuse gradient texture is set up in such a way that it ignores the UVs and uses the viewing angle instead.
You can copy and paste this map to any slot or material that you like and use it.

We know how useful this workflow can be and it'll certainly become available (via the UI) in the future.

Regards,
Konstantin

[wmcrmr]

Did this change? konstantin_chaos I used you material (it blocks all previews of materials and itself, after loaded) but the effect is what I am after. Just curious if there is now a better way to achieve this in the latest version?

[konstantin_chaos]

Did this change? konstantin_chaos I used you material (it blocks all previews of materials and itself, after loaded) but the effect is what I am after. Just curious if there is now a better way to achieve this in the latest version?

Unfortunately still not.
I'll raise it's priority.

Thank you for bringing my attention back to this.

Konstantin

[Allotope]

Was this resolved at all? Hitting a dead end in the documentation/with google.

[konstantin_chaos]

Hi Allotope ,

The feature requested here is still not available.
I'll write in this thread once we make progress.

Konstantin