Daylight and Dusk

[OPEN_RANGE]

Thanks for your reply. I have the white balance on the camera set to 100% white so that it is not affecting the colors of the scene but rather the lighting is doing that. The white balance and camera exposure settings (f-stop, shutter speed, ISO) are unchanged between the daylight scene (see at beginning of thread) and the dusk scene. For the dusk scene, I used hdri map render multiplier to control exposure versus changing camera exposure or white balance settings. So I believe that the hdri map is what's introducing all that color to the dusk scene. That is what I expected it to do even though the result is not so good

Not sure if this is relevant but below is from a different thread that I asked this question in. I never got a reply and I am using the " from 3ds max" option because it made the map look the most "correct" in the mat editor.

The hdri map I am using is from HRI Skies and it shows a gamma of 1.0 when viewed from mat editor and sampled/right clicked on to show properties/image info. I am using the vray/max linear work flow set up. In the Vray HRDI map parameters in the mat editor is a Color space section. The default Type seems to be "Inverse gamma" with additional drop down choices of "None", "sRGB" and " From3DSMax". Should I be using the "From 3DS Max" option or ....?

[padre.ayuso]

Thanks for your reply. I have the white balance on the camera set to 100% white so that it is not affecting the colors of the scene but rather the lighting is doing that. The white balance and camera exposure settings (f-stop, shutter speed, ISO) are unchanged between the daylight scene (see at beginning of thread) and the dusk scene. For the dusk scene, I used hdri map render multiplier to control exposure versus changing camera exposure or white balance settings. So I believe that the hdri map is what's introducing all that color to the dusk scene. That is what I expected it to do even though the result is not so good

Not sure if this is relevant but below is from a different thread that I asked this question in. I never got a reply and I am using the " from 3ds max" option because it made the map look the most "correct" in the mat editor.

The hdri map I am using is from HRI Skies and it shows a gamma of 1.0 when viewed from mat editor and sampled/right clicked on to show properties/image info. I am using the vray/max linear work flow set up. In the Vray HRDI map parameters in the mat editor is a Color space section. The default Type seems to be "Inverse gamma" with additional drop down choices of "None", "sRGB" and " From3DSMax". Should I be using the "From 3DS Max" option or ....?

I'll reiterate to read that article I just sent you. The settings after that should make sense. The only thing I can't tell you about is using Gamma at 1, etc., since I don't use that workflow, use whatever works for you, that's the motto. However, if you leave the day exposure camera settings the same at night, the answer is right there, you shouldn't. And at the same time, please read that article I sent you, it should make sense why I say that. A photographer would never have the same settings in his camera for a day shot and then again for a night shot, neither should you.

[OPEN_RANGE]

Thank you for your reply! Please know that I am not trying to argue with you just putting forward my understanding so I can be corrected. I did read the article you linked to and I understand exposure settings for photography.

I am not sure in this digital simulation if it really makes a difference whether I slow down shutter speed or increase amount of hdri multiplier? My thinking was to keep the camera exposure settings the same between daylight and dusk so I could see the effect of the daylight vray sun/sky versus hdri in a more apples to apples comparison. The tutorial I started from used the hdri render multiplier as the way to increase/decrease light amount versus adjusting camera exposure.

I am thinking that white balance is separate matter. I keep the white balance at 1.0/white so it is not casting color on the scene. Same with vray sky. I use Overide and a filter color of white. I do this for a couple of reasons.

1) I semi frequently have clients supply sherwin williams paint colors with RGB values that I must match. Or I get photos sent of colors to be matched. I can match these using Vraycolor map as long as the lights in the scene are not altering the colors (of course always a variation that exists from sun to shade areas).

2) I'm also often directed to match materials on existing buildings. I often photograph such specified building to get textures, or the same are sent to me. These exterior shots of stone or wood siding or whatever already have the sunlight/daylight "baked" in , because they were photographed in daylight. So putting a daylight colored sun light, or colored white balance on that changes the appearance of the texture. I hope this is understandable and would be receptive to an explanation of why my approach is flawed or not good.

With this scene I am trying to experiment and build my skills so that I can make a variation of a daylight scene that adds the evening coloring and sort of atmosphere. For such a scene I would not attempt top match color specs as described above. For my immediate purpose I just want to be able to execute a nice early evening rendering.

I'm thinking I should be using an hdri that gives a nice effect versus using white balance to alter the hdri lighting. I'm also unsure if longer shutter speed/exposure is any different that increasing render multiplier of hdri.

Thanks again for your help!

[padre.ayuso]

No worries. Here is what I can tell you. I don't do animation, so I can't guide you there. But I know VRay's camera attempts to reflect a real life camera. When you click Exposure, it will apply a real camera's effects. So ISO, Shutter Speed, etc., will take on the properties for a Nikon, Canon, Fuji, etc. I want to give you more data on this, so I'll send you a message afterwards and see if I can help you. The thing is that I'm full blast right now on a deadline, but I don't want you to think I'll not answer up.

[OPEN_RANGE]

Thank you. I'm not concerning with animation here. I feel pretty comfortable with the physical camera and exposure settings and how they relate my real world cannon digital slr camera.

In verifying what I am writing I need to revise a minor point I made above regarding the hdri map Color space setting. I said it looked " most correct" in the mat editor when Color space set to "From 3ds max". That was not quite true. I was using the mat editor view image versus how it appears in mat edit slot. It actually looks more correct in the mat editor sample slot when I keep the color space at the default setting of "Inverse Gamma".

Using that default Color space setting for the hdri map is having a major effect on the rendering appearance. The overwhelming end of the world bush fire color cast seems to have eased off a bit.

I'm going to post a revised rendering using the Inverse gamma color space for the hdri.

[OPEN_RANGE]

Thank you all for your helpful replies and patience. I think using that "For 3DS Max" color space choice in the vrayhdri map was causing me a lot of trouble. I now have it at the default choice of "Inverse Gamma". I lowered the inverse gamma amount from default 1.0 to 0.7. Went back to a 2500 color filter on interior lights.

I messed around with camera white balance a bit but it was introducing another color variable and etc so WB is still 100% white (1.0/255,255,255).

This looks better to me but maybe lacks punch? I'm not sure if trying to transform the sunny day background into a dusk appearance is also causing me trouble. my confidence in my own judgement on this has been a bit shaken so... I welcome any additional c & c. Thanks!

[werticus]

Oh, that explains it

You can't transform a sunny day background into dusk, don't even try it.

[padre.ayuso]

Thank you all for your helpful replies and patience. I think using that "For 3DS Max" color space choice in the vrayhdri map was causing me a lot of trouble. I now have it at the default choice of "Inverse Gamma". I lowered the inverse gamma amount from default 1.0 to 0.7. Went back to a 2500 color filter on interior lights.

I messed around with camera white balance a bit but it was introducing another color variable and etc so WB is still 100% white (1.0/255,255,255).

This looks better to me but maybe lacks punch? I'm not sure if trying to transform the sunny day background into a dusk appearance is also causing me trouble. my confidence in my own judgement on this has been a bit shaken so... I welcome any additional c & c. Thanks!

[ATTACH=CONFIG]31925[/ATTACH]

You are right in that it's starting to look better and you are right, it is missing that punch. I think he's using a dusk HDRI so now, what would the camera settings be? I think it should be a real camera setting, something like 1/1 for a dusk scene or even lower, while keeping the F-Stop at 8 and the ISO at 100. You want to try to darken a bit the image while keeping a bit of light coming from the sky, but not a lot. I'm guessing the sun is somewhere behind the camera? I'd have the glow of the setting sun coming in the street and see some of that on the street itself. Then add some street lights as well. Make you sky darker.... here, I'd go towards getting this result:

http://www.gettyimages.com/detail/ph...aphy/185675047

Notice the subtle things as well, the reflection on the street from the street lumps or the lights coming from the buildings. Put some lights on the buildings next door, even if just a tad to make them come alive. Give that a try, and see how it goes. If needed, bring your HDRI multiplier lower, .5?

Look forward to seeing something.

[OPEN_RANGE]

Hi and thank you guys so much for your comments. I cannot overstate how helpful this is to me.

"You can't transform a sunny day background into dusk, don't even try it."

werticus - it's too late I have already tried! <g>. that may be the best advice of all regarding this. I should have asked if that was advisable right from the start instead of trying it. I once worked as mtn safety (aka shlepper) on some film work above treeline in the snow/winter. The crew was filming "day for night". It was a Budweiser commercial that aired and it looked like night. So I thought maybe.... Now I'm thinking they probably used special film or filters or whatever to achieve that. I'm going to look into if there is photo techniques for doing this, like shoot one photo for day and then shoot at different settings for night. So you don't have to go back to the site and shoot background photo twice. Especially handy if the site requires travel time to get to. I have now learned, the hard way, that to transform day rendering to night is much easier accomplished if the entire scene, foreground, background is all CG. In cases where actual site photography is used it is best and will always be better if another dusk shot is taken. I am close to this site and I will go back and shoot a dusk shot of this as soon as I can.

padre.ayuso - I will be shooting a new dusk background photo with different/appropriate fstop, shutter speed, ISO and I will set the max physical camera to match those settings. Regarding getting sunlight on street and lights in house next door. I'm not 100% sure if that would be possible to add into my background photo. Maybe like a matte/shadow material for the street but instead a matte/light that accepted light but had the geometry as a matte? I don't know if that is possible with vray?

Your comments are spot on and now I think I see the obvious and overriding trouble. The house and the surrounding environment (site photo) are not unified. they are lit in entirely different ways and it is doubtful that any amount of tweaking the site photo will ever result in a nice, unified rendering. The original day light render and site photo (which has some retouching done in the area around the mtn/cloud area and pine tree area) are shown below FYI.

I am going to shoot a new site photo and will post the results. It may take a while, I have some other work to take care of. I'm afraid this thread has gotten so long that I'm thinking I should start a new thread when I post my revised render with new photo? Or, if you think it's better and not a problem to keep adding to this thread I am happy to do so. Thanks again for your very helpful comments!!

[werticus]

The daylight scene is well matched, and realistic. I would be tempted to reduce the contrast on the background image a bit, it is very high and probably not quite like the 3d part.

Also the windows you have are a lot more transparent than the house next door.

Not a lot you can do with a house that looks like shit, and has pink windows as well. HAHAHAAAAaaaaaaa... pink, that is hilarious.

[OPEN_RANGE]

thanks for your comments, they are very helpful!

well... I guess you can put lipstick on a pig but it's still... The house is not very compelling but not offensive. It is in an area that essentially requires a victorian vernacular. The house is in a National Historic Landmark District, 1 block from the gondola terminal at the base of a world class ski resort. House pricing is appx 1K per sq ft. It will be a 5K sq ft house so as crazy as it may sound, $5 million.

Now the developer has had some comments from others like his PT person and etc. He wants to change the window frame/sash color to...... wait for it........purple.

I'm still hoping to go back and take a dusk photograph and finish my dusk experiment/skill building effort. I'll post that when completed. Thanks again to all who weighed in.

[werticus]

Ahh purple, much better :P

For your portfolio you should do a white one i think

[OPEN_RANGE]

I hope you are not too disappointed but purple got nixed and a de-saturated/pastel blue was selected. .... here is the variation.

I have taken some dusk photos and hope to re-do the dusk scene with the better background photo. It's going to be some time before I get to that so I'll likely post it as a new thread. Thanks again for your help.

[glorybound]

Looking much better. I would darken the window glass to almost black; use the house next door as an example.

[Morne]

I agree with Bobby, and make the shadows darker also. Again, use next door as ref