Artificially go brighter than white with a map

[clay_creative]

Is there a way in vray to assign a map so that is brighter than white? I know it wouldn't be physically accurate or anything, but I used to sometimes add an 'output' map to the reflection slot in Mental ray, just to boost the reflection intensity beyond white. It worked pretty well, however this doesn't work in vray. I know I could increase the IOR but i don't want to make the object more like a mirror, just boost the elements that are reflected. This is mainly so when doing post processing the reflections are really bright in 32bit colour space.

Is there any special map I can add to the vray material reflection slot that would go beyond white?

[Morne]

Cant you just stick an exposure on your reflection render element in post and boost it like that?

[clay_creative]

Yeah that would work, though I'm not a big fan of rendering passes (would have to do object ID too to isolate specific reflections). I't just adds a ton of extra work, file size, quick renders don't show the results, and there is just more room for things to go wrong, and have to re-render. A simple 'beyond white' map would be much cleaner and simpler.

[hermit.crab]

There isn't a way to do that. You would have to boost your reflection's brightness in post as mentioned. You can use a MultiMatte with the choice of object or material ids for the mask generation (make sure the reflections affect "all channels", so that they show up in the pass).

[clay_creative]

Thank you for responding.

[^Lele^]

There is one way, but it's unsafe, and will be dropped soon.
Raise the Reflection IoR to get a stronger front-facing reflection, or if it's a light, change its specular contribution to be higher.

[super gnu]

or alternatively use a vrayblend material, set to "additive" mode and put a reflective coat on there..

[super gnu]

There is one way, but it's unsafe, and will be dropped soon.
Raise the Reflection IoR to get a stronger front-facing reflection, or if it's a light, change its specular contribution to be higher.

what is being dropped soon? independently variable reflection IOR? variable light specular contribution? both of these i use regularly to achieve the look i want.

[clay_creative]

Thank you for the suggestions. Super gnu, that is a good idea, I bet that would work actually. I didn't really want to increase the IOR as this will make a mirror finish. Essentially I just wanted the reflected highlights boosted, but retain the diffuse colour, not go towards a metallic which increasing the IOR would do.

[^Lele^]

what is being dropped soon? independently variable reflection IOR? variable light specular contribution? both of these i use regularly to achieve the look i want.

Neither of those, i was referring to Additive blend to boost speculars. Also i am not sure why i said it was going to be dropped, as it's not happening.

Alas, i didn't want to promote as workflow, so i didn't mention it overtly.
It's really bad for renders to break EP making anything put out more light than that which comes in.
Additive mode should be used with great care to ensure EP was not broken at all.

[super gnu]

It's really bad for renders to break EP making anything put out more light than that which comes in.
Additive mode should be used with great care to ensure EP was not broken at all.

it sounds like it will destroy your pc or something? create a small black hole?

i assume it will likely crank up rendertimes and possibly add to scene illumination in some unexpected ways..?

[^Lele^]

it sounds like it will destroy your pc or something? create a small black hole?

i assume it will likely crank up rendertimes and possibly add to scene illumination in some unexpected ways..?

Lol, more or less a black hole or two, yeah, perhaps even entangled.

I used additive mode throughout my production career, mind you, and the one thing i had wished for it was that it should be EP at the top, but it's an impossibility.
Now, breaking EP a little (say, 1-10%)will just make the render be slightly slower, by virtue of some more noise created in specific areas.
But use this to willfully double or triple the reflection component, and it will create uncleanable fireflies, and energy which will potentially bounce all the way to the 100 times of the LC and have loads left over.
So you'll be assured your render will finish, in the affected areas, only when it will reach max AA, while it will still look noisy to the point of not being usable.

I would find other means to achieve what he wants, like change the tail ratio of GTR, change IoR, Light influence amount, all of which are safer (when not exactly all are EP).
The best way, though, would be straight up compositing after the render is done, particularly with a true path tracer.
There are a zillion ways to make simple masks, and scripts in the forum to click-rebuild a beauty.

So long as the user knows what they're going to face though, i'm personally not bothered by whatever method they choose.
Support though wouldn't be happy with me if i just said "yeah, go ahead, brilliant idea.", and then users started poking them because of the issues.