Question about LWF

[etown]

sorry, I forgot to mention it would be easier if this was built in somehow without adding a vraycolor map everytime.

[vlado]

Well, it is possible to write a custom color picker that can be used in place of the default one... would this help?

Best regards,
Vlado

[davemcd]

I think it would be a great idea Vlado. The plug-in I have Laszlo working on is nearly done which I was going to upload for everyone soon. (For those who dont know it is a plug-in that nests every diffuse channel in a color correct ONLY at render time and removes it after render, which means it also affects Xref Scenes etc)

For our particular workflow as long as it can set the gamma on any texture and /or colour in the diffuse channel and not necessarily burn in the gamma on the final image then I'm happy. And anything that avoids touching max's built in gamma stuff would be nice.

Cheers

DaveMcD

[rmejia]

A "Linear workflow" button with a global color/texture multiplier would be great.

I have a hard time making images look "right" with gamma 1. To me gamma 2.2 (sRGB) should be the default setting and gamma 1 the option

I wish that the colors and textures looked the same in the rendering as in the material editor

[MikeHampton]

Wish list

>>I wish that the colors and textures looked the same in the rendering as in the material editor

Well.. I don't wish for EVERY material to look the same in the material editor as the rendering because that's the point of doing the rendering. Every material is GOING to look different based upon the enviroment (and lighting) that it is placed in. The material is going to look much different in an exterior enviroment lit by the sun vs. a rendering lit by artifical light (and also different based upon incandescent, flourescent, HID, Sodium, LED, etc. lighting).

However, I would like to throw this out on the table for two reasons. Maybe I have been banging my head against a wall for years when there IS a way to do what I need that I just don't know that someone can help me with. If not... then what Rmejia mentioned would be worthwhile for this reason:

Working with Designers, they often think in "spot colors" or they are holding a physical material in their hand and wondering why it doesn't look EXACTLY like that in the rendering. I could argue till I'm blue in the face about how it's going to be different because it's rendered in an environment that is differernt than the enviroment we are currently standing in looking at this physical material, how individual color perception comes into play, how no matter how "physically acurate" vray may be able to be lighting currently is still more of an art than a science, how our brain does an automatic color balance of the world around us, how no one on the planet is going to care if the color is off maybe 2% (other than the designer that is complaining), and then don't even get me started on color problems when your image get's printed, and on and on.

I'm hoping some day that we will have enormous libraries of BRDF data that has been collected on almost every material imaginable that we can just plug into the material slot and get back to the art of what we are trying to achive instead of wrestling with trying to get materials and lights to behave in the way we want. A stage designer just knows they want a blue light "over there" to create a certain mood, they don't have to wrestle with the light to get it to behave like a blue light. Anything that makes me have to wrestle less so I can focus on the art more.. is good in my book.

Of course the "easier" things become for you, the easier they become for everyone else, thus we can never rest in improving our skills.

Anyway, but even THEN, I think I would still have a need for a material type that FORCES the midtone of the color/texture into the rendering. What I end up doing now far too often is I have to take what the material is in the editor slot (input) and compare that to the midtone of the color that is rendered out (output). Then I end up going back and forth a half dozen times or more adjusting the individual RGB values of the color or for a bitmap image, adjusting the color mapping in the editor or the image itself in photoshop. I keep tweeking until the output is as close as I can get it to the ORIGINAL input color. Now my material in the editor may look nothing like the original color it started out as... but in the rendering it's the same color as the original material in the editor.

So basically having a material that would force any object that it's on to NOT accept any color from the scene, either by color bleed or from the color of the lights AND automatically adjusts the brightness of the material in the rendering to match the midtone color of the input material/texture.

Hope that makes sense. Is there a way to do this now? If not, this would be a killer feature for anyone who has ever heard the phrase "Is that color right?".

[beestee]

What I end up doing now far too often is I have to take what the material is in the editor slot (input) and compare that to the midtone of the color that is rendered out (output). Then I end up going back and forth a half dozen times or more adjusting the individual RGB values of the color or for a bitmap image, adjusting the color mapping in the editor or the image itself in photoshop. I keep tweeking until the output is as close as I can get it to the ORIGINAL input color. Now my material in the editor may look nothing like the original color it started out as... but in the rendering it's the same color as the original material in the editor.

Is there a way to do this now?

We are getting a 99% accuracy on our RGB input to output values for exteriors.

I am curious if the settings we use would work on sombody else's setup.

Try these settings:

-Default VRaySky


-VRaySun

Turbidity: 8.0

Ozone: 0.32

Intensity: 10

Target @ 0,0,0

Sun Node @ (d*1), -(d*1), (d*1.333) where d=unit specific distance to set the sun outside scene boundaries(ex. 1000ft or 300m)

-VRayPhysicalCam

f-number: 8.0

white balance: custom

255, 252, 221

shutter: 600

ISO: 26.2

-Color Mapping

Reinhard

Multiplier: 0.9

Burn Value: 0.95

Gamma: 2.2

-We have switched to using bitmaps for our color swatches, so we do our matching in PS and have a library to draw our past matches from. This also allows us to not use color correct or vray color map for the gamma correction because we just have the option for bitmap input set to 2.2 so it will automatically adjust bitmaps. Also, with bitmap output set to 1.0, the colors will appear consistent between the mat editor and the final render.

-If you use the VRay Frame Buffer, you can right click in the frame buffer for spot color checking, which is extremely useful when you are trying to incrimentally tweak settings.

-The way that I came up with these settings was to use a 128 gray, a 255 white, and a 0 black to test how the lighting was affecting neutral colors. I adjusted for the color offset by using the camera's custom white balance. I also used the float values that I was getting from the spot color check to see if my white was being blown out. I adjusted for this brightness and contrast imbalance by using the Reinhard color mapping multiplier and burn value.

[MikeHampton]

beestee,

Exterior's usually arn't the problem because there is only two light sources (unless doing a night shot). That's not where I usually have problems with colors.. it's always on an interior where the colors of things are so dependant upon the lighting and enviroment. And I'm not saying that the colors in the renderings are even "wrong".. just that based upon the lighting and enviroment they ARE going to be deferent than the raw color from the material. Heck, even in the real world, how many millions of times does someone pick a paint color from a swatch, but then when it's painted on the wall of their house/building they are like.. "that looks TOTALLY different." But then they put the swatch upto the color and it's an exact match. I'm not even saying that I WANT the colors to be an exact match... there's just times where I DO need it to ignore everything and render as almost a spot color that is exactly what the input is.

But you bring up another interesting thing that I am running into. I'm trying to get all my guys on the same page when it comes to lighting in Vray because everyone has gone off on wierd tangents. So when we open up each other's files, we don't understand at all how each other has lit the scene. I try not to have too many guidlines, I don't want to curtail creativity or slow people down.. but we each must at least start on the same page so that we understand the overall scheme of any file we have to jump on.

In your settings.. I don't understand at all why you would increase the intensity of the sun by a factor of 10?? :O It looks like you are offseting that impossibly bright light source by using unusual camera settings. I guess they do make an ISO 25 film.. with is a unusally slow film that requires LOTS of light, which you have in abundance. But more typically you probably wouldn't use below 100. Then combined with what is a "relatively" fast shutter speed of 1/600 s. Again.. just seems like a very unusual combination of camera settings all stemming out of necissity from having a sun intensity of 10.

What I have tried to do is light my scene with lumen values (which make sense to me) which results in camera settings that also make sense to me, meaning more or less what the setting would be in the real world. Then I put a "white" box at the focal point of the camera and do a rendering. The color that box renders is my color balance setting. This is more or less exactly how you would manually white balance a real camera.

But anyway.. I'm not saying your process is wrong at all.. if it works.. that's all that matters. It's always interesting to see how other people do things.

[beestee]

I had complaints about dark shadows with the standard physical setup...the turbidity and sun intensity were increased to compensate this by deeper light penetration by using an impossibly high amount of energy for the sun. I tried different color mapping modes, but the adjustments were not consistent in the areas that they needed to be (dark colored materials were being unmanagably boosted). It should be as easy as adjusting camera settings, but the problem traced back to the balance of a visually desireable result vs physical accuracy.

I have been doing my interiors in a similar way, but I do find myself using a lot of override materials so that the GI contribution is neutral in color and intensity.

[MikeHampton]

I had complaints about dark shadows with the standard physical setup...the turbidity and sun intensity were increased to compensate this by deeper light penetration by using an impossibly high amount of energy for the sun. I tried different color mapping modes, but the adjustments were not consistent in the areas that they needed to be (dark colored materials were being unmanagably boosted). It should be as easy as adjusting camera settings, but the problem traced back to the balance of a visually desireable result vs physical accuracy.

I have been doing my interiors in a similar way, but I do find myself using a lot of override materials so that the GI contribution is neutral in color and intensity.

Oh I see... that's definatly one way to brighten your shadows. I've not had complaints like that before.. but when I've felt that I needed to brighten the areas in shadow, the Photoshop Shadow/highlight filter has been a lifesaver for me.

[beestee]

I have used shadow/highlight in the past, and it is definately a lifesaver. However, I work in a group of 6, and if you don't keep track of the numbers you used for a specific project and then it comes back in revision...let's just say that some individuals are not so comforatble with just "making it look right"

[rmejia]

Is there any way to make the V-Ray frame buffer get the Pixel information from the sRGB or the color curve correction modifications ?

[^Lele^]

Then I put a "white" box at the focal point of the camera and do a rendering. The color that box renders is my color balance setting. This is more or less exactly how you would manually white balance a real camera.

And incidentally how my exposimeter works for colorbalancing / exposing a camera correctly.

One thing worth mentioning is that all the photos, particularly where interiors and exteriors have to be seen, are NOT done in one shot.
Bracketing for indoors and outdoors and comping them together later is the way forward, so I don't really understand why people require a different behavior from the VRay engine.
Sure, there are FP values and color corrections that aren't available in a normal camera, but still there HAS to be some post-work done to compensate LOCALLY for the look one is after.
Well, in my opinion, of course

[^Lele^]

Well, it is possible to write a custom color picker that can be used in place of the default one... would this help?

Best regards,
Vlado

Would it then not revert to an 8 bit color representation, this way?
I like the vraycolormap, personally.

[vlado]

Hm, you have a point here... the color picker can only return 24-bit color values.

Best regards,
Vlado

[MikeHampton]

One thing worth mentioning is that all the photos, particularly where interiors and exteriors have to be seen, are NOT done in one shot.
Bracketing for indoors and outdoors and comping them together later is the way forward, so I don't really understand why people require a different behavior from the VRay engine.
Sure, there are FP values and color corrections that aren't available in a normal camera, but still there HAS to be some post-work done to compensate LOCALLY for the look one is after.
Well, in my opinion, of course

That depends upon weither you are trying to match what the human eye sees or match what a one shot photo would look like. Doesn't the human eye have the equivilant of like 57 fstops or something like that? So yes for any shots that have EXTREME lighting level differences.. like the difference between the sun and ANY artificial lighting, you need to take a different exposure between one and the other and comp them together if you want to see both properly exposed more like what the human eye would see.

Personally on interior scenes.. I don't mind haveing glowing blown out windows where the exterior is washed out some. When I am working with people who don't like that, then I've been able to get around it with colormapping and such. I HAVE to do it in one rendering.. at least for work where I have insane deadlines, because I barely have time to render it once... I definatly don't have time to render things twice. And when you have to make 37 revisions to something, I certainly don't have time to render it 74 times! lol