General Vray rendering/lighting help


#1

I’ve got a basic work in progress scene I’m working on. The geometry, textures and lighting are all pretty basic. I’m experimenting with Vray lighting and rendering and really just looking for ways to take my scene to the next level.

Any info on ‘must do’ tips or tricks to get things looking a bit better would really be appreciated. I dont know much about vray or setting up a scene to render in general so any help is welcome.

Also, why when I ‘Render production’ do I get a darker image to what I get when I ‘Save Image’ using the floppy disk . The saved png/jpg looks much darker.

Thanks in advance.


#2

Your images look different because one is saving in RGB space and one is saving in linear space. That’s part of the linear workflow, but also the “Save Image” options too.

The model and textures look pretty good. I’d change up those windows and make them much more reflective, and add a sky dome so they have something TO reflect as well. A very light, broad fractal bump will give them the warp of real glass.

Also consider a backdrop - that’s the first thing that stands out!


#3

Thank you so much for your help!

I can now see the difference between the RGB space and what my render window calls ‘Use ICC correction’.

The trouble is now, I dont know how to save the image using ICC correction. Or even if thats possible? My render is always saving in the RGB space by default…apologies if that is a dumb question.

I am working on the windows trying to get them more reflective. I’m going to add a fence to cut out the back drop and a sky dome to improve the sky - great advice!

Thanks again.


#4

There are two ways to save the images manually - through the Vray Framebuffer (render window) or through the standard rendering window. You can “Send” the Vray framebuffer to Maya’s native framebuffer and save it from there, just make sure in your “Save Image As…” options you have the correct colorspace clicked or unclicked. I can’t remember exactly what it looks like right now, but there’s only two options there so one should work.

Or you can save it directly from the Vray Framebuffer, which I don’t usually do but it probably has options too. Also, down at the bottom of the VRFB there you’ll see a bunch of little icons. One of those sets your colorspace correct, mouse-hover over them and you’ll find it. If you didn’t already! :slight_smile:

If you need more help I’ll pull up Maya tomorrow and take some screenshots for you. Either way, the gamma difference should be 2.2 / .454, so your current saved image will look correct if you fix that in Photoshop for example, in the Exposure controls (Gamma though, NOT the actual main Exposure slider).


#5

Why is this all so confusing, but yet important?

Because the TOP render there looks great on a monitor, but it’s the BOTTOM one that will be much closer to proper in print. You may not print a lot, but that’s chiefly the difference involved in Linear WorkFlow.

The other main difference is that lights inside Maya and Vray will look more realistic and proper and not “blown out” as easily, since the light spectrum is linear instead of just values. So if you double the intensity of a given light, it will LOOK doubled in the rendering instead of just some weird whatever value. It’s supposed to make lighting more predictable and easy.


#6

I see…This has opened my eyes to colour spaces etc. and has been super helpful!

I really appreciate your time/effort/help!

Thank you!


#7

Up until this comment you are correct.

If anything your image would print much darker than your VFB image, printed colors are subtractive, not additive. Linear workflow has nothing to do with print, it has to do with interpreted colors from your monitor (your have light projected from the monitor). Linear workflow was created to have a standard for floating point images to be transferred to other departments so that they can be interpreted for that colour space, such as dealing with different camera/composition profiles, red, canon, fuji, etc so you can then bring a rendered image into that space without losing any colour.

If you have your printer profile & monitor calibrated then it should look 100% the same, if not then an adobe 1998 color space would print closer to your image (with about 10% extra brightness added in post) if using a CMYK printer. You also have more common RGB printers these days, you need to calibrate these to the intended profile, otherwise its just a guessing game.

edit: Not to mention the change from CRT to LCD monitors, this was the initial requirement for linear workflow as the images as displayed differently.


#8

Please consult every printer ever made for a quick lesson in color theory and how printers work. The brighter image will print closer to “correct” than the top image, though it looks a bit washed out on a monitor. Printers are not “subtractive”, because you cannot subtract ink. You can only spray ink on the paper - you cannot spray not-ink, since that doesn’t exist. That is an additive medium, by definition. You will say they are subtracting from the background white, and that is true enough, but that’s not what we’re talking about here. They do not SPRAY white. They only spray colors darker than white. We’re not talking about additive/subtractive in the Photoshop sense, but in the INK sense.

OP was not concerned about print that I know of, I was simply pointing out that the bottom render would look better in print, and why. If you think LWF has nothing to do with print that’s totally fine, just let us know when you actually start printing your renderings so we can help you fix all the problems with your opinion.

I will take a photo of both renderings printed tomorrow to show you what this means if that will help.


#9

Yes you are correct, the ‘washed out’ image will print better - my mistake I thought you meant the darker image will print closer to the vfb.

In regards to printing my renderings, all my renders go to print, either newspapers, flyers, magazines and billboards so yes I have some experience in this area.


#10

Well, it was MY mistake to be a jerk about it. I apologize, NorthernDoubt. I’m sure we’re on the same page, and I didn’t need to be snide.


#11

Appreciate the kind words InfernalDarkness! I didnt take offense to what you said, thats what I love about 3D artists, - we are so passionate about our work and we all have so much good knowledge to share :smiley: