monochrome reflections?

[elektrosport]

I may have missed something vital, but how does one accomplish monochrome reflections with vray?
This may either be silver, gold or whatever colour desired. Simply applying a colour to reflection value doesn't seem to do it, not satisfactory atleast.

cheers,
Karsten

[Trapezium]

In a VRayMtl under the Options there is a dropdown box for Energy preservation mode. You might also want to try out the Ward BRDF for metals.

--Jon

[elektrosport]

ok, I'll try that.. see if it helps me..

It's not necessarily metals I'm going after, a lot of materials only reflect their own colour and I'd like to be able to do those without having to use the max standard material, ideally.


cheers,
K

[elektrosport]

ok, I've given it a test and changing energy preservation mode to monochrome doesn't do anything to my reflections.

I guess the best(?) way of doing this, is a standard material with a color correct (mono checked) in the reflection slot followed by a vraymap.

Atleast that's my only solution so far.

Any takers?


cheers,
K.

[Trapezium]

Hmmm, it works fine for me What's your diffuse set to? Are you using Fresnel? Maybe if you post a screen of your material (always a good idea) I can help more.

Edit: Here is a quick example I made



BTW, what othr materials only reflect their own colors? I always thought it has to do with the fact that metal is a good conductor of energy.

--Jon

[elektrosport]

interesting, this works as long as I don't put any map in the reflection slot, if I put a fall-off it goes!..

Anyway thanks a bunch for your help.

I'm afraid I can't post any images of my material right now, imageuploader seems to be busy.


cheers,
K.

[Trapezium]

But what other materials do this? I'm racking my brain now that you've mentioned it.

--Jon

[elektrosport]

what other materials?..

I'm not sure I can give you an exact answer.
I've observed plastics do this, metals of course, some foils, but also my orange hi-gloss dining table does this.

I went to a lecture a couple of years back where I got the theory behind why some materials hold these properties but I can't really remember what exactly it was about, atleast nothing I'd be saying here as it's only vaguely present inside.


cheers,
Karsten[/quote]

[Trapezium]

Good point I didn't think about a multi-layered material like the table. I'd imagine that's actually the transparency of the top layer tinting the reflection but monochrome reflections would be a good way of kinda faking it. Observation is what it's all about

Foils can be considered metals and I'm sure that plastics don't do this unless they have some metal in them or are multi-layered and the refraction is tinting it like the table. Always curious, thanks for helping me get it out of my head

--Jon

[elektrosport]

well, I'm not a 100% percent certain, but I really believe I've seen _hard_ plastic objects, hi-gloss only reflecting the diffuse colour, or maybe I just really it?

The foil I'm thinking of is a foil where reflections change colour depending on the viewing angle. It's really neat!

There may be metal in it, there may not be.. I dont know?


cheers,
K.

[Trapezium]

I always end up saying that relying on observations is the best bet for artists but sometimes I get caught hovering over that fine line thinking, " What is accurate way to make this material?" We don't always have the best control to make them physically accurate and sometimes working this way just makes the render times ridiculous.

Check out Neil Blevins site for some clearly written observations. Here is a direct link to his thoughts on metals, which somewhat relates to what we've been discussing.

http://www.neilblevins.com/cg_educat...l_and_refs.htm

--Jon

[elektrosport]

I already knew about blevins, and used to visit his site frequently. I had completely forgotten about him though, until you mentioned him here.

On another note.
I just remembered the part of the lecture I was referring to.
It was about how non-metals could act like metals, the example he gave was insects, some species of beatles to be exact, whose shields hold metallic-like properties.
As he started to research into this he learnt how to make a perfectly reflecting non-metallic foil, only to find out 3M already had done this.

cheers,
Karsten

[v_wrangler]

Re: monochrome reflections?

FOr standard mats, you could nest the vraymap unto a color correct and
make adjustments to saturation/rgb/make it mono/invert/ etc. from there.
One of the best plugins ever. Can't live without it

[elektrosport]

yes, color correct is a brilliant map type, however it requires I used the standard mats, as you mention, to be able to help me accomplish what I desire.
I'd rather there would be similar color correcting options on reflections and refractions in the vray mat.

Considering development has taken a turn to implement fakes like the highlight option, I would really like to see a more alternative control over reflections, refractions etc.
For instance to be able to make glass behave as completely transparent, ie. not reducing light intensity based on reflection amount.
A complete color control, would be great aswell, saturation, contrast brightness, hue etc.


cheers,
K.