LWF and bump and falloff?

[DP]

quick q's, apologies if covered before.

have set max to 2.2 gamma with 2.2 input gamma on bitmaps, affect color and affect material. All is well.

Using color correct plugin to shift colour swatches to 2.2 as well. Fine.

Are bump map bitmaps and/or falloff materials affected? If i wish to retain the look of these from an old file in a new one using LWF how should I handle them?

(or should i say, bump map materials will be affected, but should they be left or adjusted back to retain the same effect without LWF)

Also if using a colour in reflection overide in vray enviroment, should this have colour correct applied to it or not?

Its tricky because i've adjusted the lighting now to suit the new gamma, and i'm not sure if falloff that's driving a reflection mask is different because of that or the gamma shift being applied.

[joconnell]

With lwf the only things you'll need to colour correct are your diffuse maps or any other channel that makes use of colour instead of just simple brightness values such as your bump.

Bump maps should be the same but what will happen is that they'll appear weaker - since bump is a visual trick done by putting shadowing on an object and lwf lightens shadows it'll weaken the bump effect - you might find you need to push your bump a bit to get the same perceived effect.

Falloff maps are probably going to work a bit differently too since the diffuse surface your reflections are lying on will be lighter and thus your reflections won't have as much difference in brightness as before.

In terms of your question I'm not entirely sure if the falloff map is being gamma corrected via the max gamma setting so Vlado will have to step in, but it only becomes an issue with scenes being converted across to lwf - if you start a fresh scene you set your reflection levels visually and relative to the scene too so it's less of a problem.

[Clifton Santiago]

I would assume that as falloff maps are procedural, and use color swatch colors that would not be affected. However, if your bitmap input is 2.2, then I think all bitmaps would be corrected, regardless of slot. It something I never worried about before. Maybe I should start...

The solution would be to put the map into color correct and inverse gamma correct it... .4545

[DP]

yep, like you say, it's no big deal and really not a problem, but it's just something I wondered about.

will do some more testing.

actually, ive remembered what might be the problem :

the gradient between black and white being a straight line in falloff, gives a certain gradient...but if we move to LWF, does that gradient not change its effect, as the numbers would probably be the same along the gradient, but the effect different...so perhaps the gradient itself needs a gamma shift curve back to perform the same? (make sense?)

[flipside]

When I use gradient map, I indeed use an inverse gamma on it, or it will look completly different than what you're used to.

I also correct bump and displacement maps, since the transition between black and white changes a lot, so your bump/displacement should also look different, not only because of the lighter shadows. But this I actually never tested, I just assumed it worked like that

[J_man]

but if your bump maps / displace maps are created in photoshop or using a specialist app then they're proabably already mapped in linear colourspace. If they're derived of a photo then you need to change them.

Josh.

[stef.thomas]

Just to complicate things further, your reflection/refraction swatches don't just have to be grayscale. You can tint them using a colour, I quite often use a green tint in my refraction slot for glazing for instance, rather than bothering with fog (which to me is more suited for solid objects rather than thin planes). How is this affected by the gamma issue?

I think the answer is that most of these decisions are made by eye, so just use whatever looks good on a test render. It's not like you are trying to match any particular colours is it?