Ramp Shader in Vray

[irwit]

Hi all

Theres a great feature in the ramp shader where you can set the specular colour falloff colours which gives you great control of your shader. ie you can set a red for the beginning of the specular highlight and blue for later in the falloff of the specular highlight. Please note that this is not the same as fresnel shader fallloff, it is based on falloff from the specular highlight, not falloff from facing angles of the geometry.

Now I cant use this shader on its own as there isn't enough control, so I want to be able to combine it with a vray shader but when I plug it into a blend material it just shows as transparent.

I also try plugging its result into a surface shader and then into a blend but that doesnt work either.


So I have 2 questions.

1: is there a way to combine the ramp shader with a vray shader or

2: is there another way to get this kind of control of colours on your specular highlights via ramp texture and something else ?

Thanks for reading

Will.

[vlado]

You might be able to get what you need by layering several VRayMtl materials with different reflection colors and different glossiness amounts. About the Ramp shader not working inside a VRayBlendMtl material - I've made a note about this and we'll look into it.

Best regards,
Vlado

[irwit]

Thanks for the reply Vlado,

Is there a way to disable reflections on a vray material so I can just have the shader emit specular?

[Yannick]

Hey Will,
You can reduce the reflection glossiness and uncheck trace reflection. That should give you only the specular.

[Metzger]

Vray doesn't work like Mental ray in that way. Specular is reflection. If you have a light, or color that goes past a certin value of intensity, it is thrown into the "Specular" render element.

Also, there is no need to use a Ramp shader when you can actually use the Vray Fresel texture for everything including what Vlado suggested by using Material blends and throwing a Vray Fresnel texture into the blend amount, or even a dirtmap shader.. All other techniques can be created by using the sampler info and a maya texture Ramp. I personally never have any need to use any Maya shader in Vray. Plus, do all Maya shaders properly break down with Vray Materials when comping with vray render elements?

[irwit]

Cheers Yannik, that's spot on

Thanks for info Metzger, do you have any links or more info into when a highlight goes from specular to reflection as that would be very useful when setting up scenes.

As for the question about the shader, what I am after is not fresnel, as I put in my original post. What I am after is control over the specular falloff values, which work based from the highlight point of a spec highlight, and not the facing angle of the object, ala, vray fresnel material.

If you have any ideas how to replicate spec falloff gradients as a texture or a material that a vray blend can read, that would be a great help.

Thanks again for the replies guys.

Will.

[Yannick]

The only way I found is to create several VrayMtl with different colour and size in the highlight and then use a vrayblendMtl. But even by doing so, the highlight seems to be added and lose their colour.

Will, 2:24 am, really?

[irwit]

Yeah I think that is going to have to be my best route until the ramp shader starts working.

As for the time Im in San Francisco at the moment

[ivaylo.ivanov]

Ramp Shader will work with VRayBlendMtl in the next nightly build.