Environment

[glorybound]

How do I brighten my shadows? I can crank my HDRI up, which seems to exponentially increase my highlights and doesn't have too much effect on my shadows. When I drop my HDRI in the MAX or V-Ray Environment slot, nothing happens after I crank it up there. My HDRI is in a V-Ray Dome and set to visible with a V-Ray sun aligned with the brightest part of my HDRI. I can set the HDRI to invisible and use a copy in MAX's Environment slot to control the sky separately, but it has no effect on the shadows. I am using all NEXT defaults.

[MANUEL_MOUSIOL]

The vray sun has very dark Shadows when it's bright. You would have to balance it with the HDRI you're using to brighten the shadows. You could of course cheat and set another vray sun to not cast shadows and get the brightness you want, but that would probably be weird.
or brighten the shadows in post with a shadow render element.
are we talking about exteriors or interiors?
Could you post some examples?

[glorybound]

Yes, it is exteriors. I do brighten the shadows in post-production, but I am trying to get it right in the render. I have my HDRI to a multiplier of 100 and I think I might have it. Usually, I have it between 30-60.

[MANUEL_MOUSIOL]

So the sun at 30-60 and hdri to 100?
I'd have to do some tests..
But:
i would check the workflow here https://forums.chaosgroup.com/forum/...-for-interiors
Forget about linear and outputting 32bit files and going through arionfx or so. Just gave me troubles.
Cranking down highlight burn will probably solve your problems.

[M.Max]

Rise your hdri gamma to decrease the contrast in the lighting ..
you can do that on a clone of your hdri to avoid flat sky look by using the original one in the environment tab while your dome is set to invisible .

[MANUEL_MOUSIOL]

There's no way to brighten shadows of the vray sun, no?

[joconnell]

Shadows are the place where a light can't see so you have to brighten up whatever other light is shining into those areas!

[M.Max]

There's no way to brighten shadows of the vray sun, no?

when I need to darken or brighten my shadows I usually take the V-Ray sky to material editor and play with sun intensity ( consider it as Sky light intensity ) .
I like to think of it this way :
what makes the shadow exist ? the sun
why these shadows are not fully black then ? because of the sky light (mainly)
the brightness of the shadow ( if we ignore camera exposure) comes from the difference between sun intensity and sky light intensity . so if you increase one of them this deference will change .
check the examples below :
the default ( sun 1.0 , Sky 1.0 )
the darker shadow ( Sun 1.0 , Sky 0.1)
the bright shadow ( Sun 1.0 , Sky 2.0)
to keep the same exposure I had to change camera exposure a bit between these 3 renders . one thing you need to be aware of too that the overall mood colors will change as well and that's expected . you need to re-balance that to your liking ( change sun color manually or color correct the sky ).
Other rendered have simple slider to darken and brighten your shadows but vray sun doesn't have this ( yet ?)

[MANUEL_MOUSIOL]

Yes, that's what I meant by balancing the HDRI against the vray sun.
even if it's fake (but what isn't?) Having control of the shadow intensity with a vray sun would surely be helpful

[glorybound]

Why doesn't the environment slots work? Shouldn't dropping the V-Ray Sky there and cranking it up to do exactly what is needed?

[M.Max]

Why doesn't the environment slots work? Shouldn't dropping the V-Ray Sky there and cranking it up to do exactly what is needed?

by default your HDRI in environment tab will have no effect at all on your lighting if there is a dome in your scene that affect the lighting.
to see the effect you need to use that adjusted hdri inside VRay dome or turn off the dome ( I don't recommend that ).
let me tell you why.
if we ignore reflection, refraction and visibility VRay will go this way :
Dome light >> VRay GI environment >> Max Environment
in that order the first one that VRay find exist (or enabled) will use and ignore the rest .
usually when I explain this to my students I plug red , green and blue colors into these 3 and turn them on and off while IPR running so they can see the effect .
Visibility ,reflection and refraction go the same way too except that we don't have visibility environment under VRayrender setup so VRaywill only look at the other 2 places .
it might seem complicated at first, but if you test this in simple scene I'm sure it will be clear .

[MANUEL_MOUSIOL]

Btw, is there a difference in quality between these three?

[M.Max]

Btw, is there a difference in quality between these three?

For lighting I will almost always go with Dome light ..just drop a sunny hdri ( good one like from cg source, hdri haven ) into dome light and render and use the same hdri but with the other 2 and you can see how only dome can produce direct sun light and nice shadows .

[glorybound]

It has to be my materials because the gray-scale always looks nice.

[squintnic]

sounds like it just needs tone mapping to lift the shadows and compress those highlights
why are you using a sun with HDRI - gonna look weird

some pretty cooked suggestions in this thread, 2 suns are something you might do in 1994. keep it simple, respect albedo / black / white values and it will look good