More control over Material IOR

[Bart247]

Adding more control to the IOR in the V-Ray material would go a long way.

Something like the mental ray MIA material where you can set the front and side angles individually in units directly in the material settings would be good.
Better yet, an option to also have a graph where you could adjust the curve manually.

This would add the the ability to create very physically accurate materials.
For example the IOR curve for aluminum... http://refractiveindex.info/?group=M...rial=Aluminium

[Dariusz Makowski (Dadal)]

Same request for both maya and max - 1st of all numerical please my mental ray shaders range between 0.0001 and 0.0004 changes...

Plox chaos !

also a "K" value please...

[Yannick]

While at it, could we get a thin wall option like the mia material. This is really usefull for glass made of 1 surface.

Thanks,
Yannick

[jbvfx]

The fresnel equation used in vray is only for dielectric materials, and using ior values around 50-100 to mimic the reflective quality of metals will give you an incorrect falloff curve between 0 - 90 degree angle reflectivity.

Mental ray's MIA material has the old Schlick's approximation equation, where you specify the front, side angles and the curve - which gives you greater control over the falloff.

It would be awesome if Vray could get an option to use the fresnel equation for conductive materials, where the absorption coefficient is taking into account (The K value as DADAL stated).

Thanks,
Jacob

[vlado]

If you want manual contol, then a Ramp node works just fine. Implementation of complex IOR (the "K" value) is planned and will be done.

Best regards,
Vlado

[jasonhuang1115]

Hi Vlado,
Just re-visited this thread and before I jump to work my way through Maya's hypdershade to construct nodes for mimicking a custom reflection falloff (really wish to see a Max-like bezier curve control in Maya), where are we on the implementation of the "K" coefficient for metal's complex IOR? Is it still way down the to-do list or there is already a better approach in the nightlies of Vray for Maya 3.0 beta?

If you want manual contol, then a Ramp node works just fine. Implementation of complex IOR (the "K" value) is planned and will be done.

Best regards,
Vlado

[vlado]

It is still on the "to do" list, haven't gotten there yet. It is also possible to provide a texture with a custom curve - we have one in the V-Ray SDK anyways, just need to code UI for it.

Best regards,
Vlado

[Neilg]

If you want manual contol, then a Ramp node works just fine. Implementation of complex IOR (the "K" value) is planned and will be done.

Best regards,
Vlado

Great news
Will there be easy controls to split up the RGB values too?

[vlado]

Not for the first implementation...

Best regards,
Vlado

[jasonhuang1115]

or would it be easier for Chaos Group to code a control curve UI (like the one in Max) for Maya?
I mean we can do the math outside of Maya to get custom reflection falloff curve (single or RGB separately) for mimicking in Maya. On top of that, the calculated curve may well be mimicked for the initial look and still be adjusted more or less anyway to achieve designed look by users. We need the flexibility and maybe it's better than implementing the "K" coefficient and be stuck with the result??

[joconnell]

At least it's only a composite material / layered texture in add mode to combine three curves for different RGB values. Having script access to the flags of the ramp / custom curve would be great too. 3dsmax misses a lot by not having the option of creating flags along the gradient ramp map and there's no maxscript access to the output curve section either so it prevents us from using any scanned curve data easily.

[Ihno]

This is also the first thing i would like to have next.

Something like the Potoshop Curves, where i can edit the curve directly and change the RGB chanals in particular if i whant to.

Postet here because i can´t find a thread like this in the 3ds Max Wishlist.

[Neilg]

Something like the Potoshop Curves, where i can edit the curve directly and change the RGB chanals in particular if i whant to.

You probably already know this, but if you add a falloff and scroll down to the color map in output, you can break that up into rgb. it's just kind of awkward to control, but worth making a couple and saving them out.

[joconnell]

I'd love if autodesk added in script support there, but as usual they didn't