HDRI lighting and brightness.
metaldragonman
Posts: 17
Hello,
I have an interior I have been trying to light up from the outside. Lights off in the day sort of thing. I put in a HDRI and it lights up the room a bit but not nearly enough. So I make it brighter, either on the intensity bar or the environment image select bar. Either way when I do, it lights up the room quite nicely but it also drowns out the background image in light making it look unreal.
Is there a way I can change the brightness of it without that happening?
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Maybe this similar discussion will help (although I got very lost among the technical details) ... https://www.daz3d.com/forums/discussion/596591/using-hdri-on-indoor-scene
Change the camera settings in Tone Mapping for an interior shot. Try Shutter Speed 60, F/stop 4.0, ISO 200 and go from there.
I've checked out that link, and yeah I'm a bit lost on it too. I'll read it again.
As for those settings, I've had a go with it and I'm not quite there yet. Light is a bit much and getting it to come in from the outside is tricky for me. I still get the outside looking too bright with a washed out image.
I did try out the sun-sky setting and I managed to get some decent shadows and light direction but the render time suffered for it.
People suggest taking ceilings away but all that does is make a large pool of light flood in from the top, as if the ceiling is a light anyway and it ruins any shadows and window light because loads of it is coming from the top now. Makes it look flat.
So with a HDRI and fiddling with those settings, I have managed to at least get closer to what I want. I can get the shadows and whatnot but it's a bit dim, and I still get the problem of the HDRI image being washed out otherwise. I have tried putting walls in with images on them but the HDRI also affects those. It can look good inside, but outside looks like a nuke has gone off.
You could try getting the light intesity the way you want and rendering to PNG with the Draw Dome option turned off. Then, with the same camera, also render just the dome with the light intensity adjusted so that it looks the way you want. Layer in an image editor like Photoshop or GIMP.
I think the problem is that you are looking at it from an 'eye' view rather than a 'camera' view. Our brain takes in the view from our eyes and interprets the image of light and dark and lets us see a balanced image, the camera doesn't. The light through the lens is the same but the software only sees light areas or dark areas and has trouble balancing these to get an image that matches our eyes. If you set the camera to show the light area then the dark area is just that, black, and setting it for the dark area overexposes the light area which comes out white. You will either have to match the outside light to the indoor settings or the indoor light to the outside settings and even then it may not look the way you want it.
Yeah it's confusing. I have been fiddling with the tone mapping settings some more and parts of the interior I do like. I have come up with a workaround though. I placed in a plane, made it black, then made it a little bit transparent and placed it outside of the window (Thinking about it, I probably could have just done this to the window.) This did not change the lighting much that I notice. You can't see the plane despite it not being fully transparrent, and it makes the outside look like the outside. It doesn't fully get what I want but it helps. If the outside doesn't change much when I am affecting the inside then I'll be happier with it. If push comes to shove, I'll use GIMP but I'd rather not if I can avoid it.
Is it something along these lines you are looking for.
Tone Mapping is 128/16/100 and I made the lights in the ceiling Emissive and set them at Luminance 10, Luminance Units cd/cm^2 to get some light in the shadows. For more interior light increase the Luminance to 15 or any number that gives you the lighting you want.
2022-10-27 21:11:29.520 Total Rendering Time: 3 minutes 43.43 seconds
Click on image for full size.
Setting the "cm2 factor" in tone mapping to 8-10 with ISO 400 fixes a lot of problems with lighting interior scenes
Yeah that worked...not. I had to stop it after 4minutes and it was only 25% converged and there is no sign of the HDRI outside the window.
Click on image for full size.
It's like a white void. I just can't get it right, I've had to concede for now and use some ceiling lights. It also heped changing the wall colours. They weren't super dark to begin with, but they were a dull grey. I have made them a lighter cream and that has had an effect in the right direction.
I've taken some images, these currently at the tone mapping suggestion you made earlier. Each took about 10 - 15 minutes to render. None of them have my previous attempts to darken the windows with the panes.
With lights on and just the HDRI
https://i.imgur.com/MP0Y5am.png
With lights on and with walls that have images
https://i.imgur.com/BIWRqZh.png
With lights off and just the HDRI
https://i.imgur.com/021at2l.png
With lights off and with walls that have images
https://i.imgur.com/wAR0cc4.png
With lights off and just the HDRI but the environment map cranked up a bit to 50. Even at 5, the windows are bright, but the interior isn't. Although knocking off the intensity a bit helps but not much.
https://i.imgur.com/j6pQ8Uq.jpg
https://i.imgur.com/cs6RWN9.png
@metaldragonman
imgur wont let me view your images. You are best to attach them to your post.
I touch on this as a third (my preferred) way to light an indoor scene ....
Ahh OK I'll try that. I'll upload the same order I linked them.
I'll check that out thanks!
I like #2 and #4
In #2 I would decrease the interior lights until they were just giving enough ambient light to lighten the walls and corners.
In #4 I would increase the interior lights for the same reason.
I would probably start at 2 cd/cm^2 and work up until the ambient light wasn't overpowering the light from the windows. The other way to do it is to use two Distant lights pointed at the two windows so they shine through them and cast light on the interior.
I think those are the better ones also. I ended up going with 2 and changing the shutter speed to 90, to try and make the background image a bit clearer, but now it's slightly darker. So yeah ceiling lights it is then. I started with cd/cm^2 at 200 and went up from there, adding 200 each time until I got to 2000. I also changed the colour of the seat drawers to the same as the walls to help brighten up the room a bit.
By the way, I really like this video and it helped me out a lot , perfect for this post. Thanks Rauko
I've checked out that video. But there's still nothing on preventing the HDRI image from being completely washed out. It's like I have come back from the opticians and had the eye drops when you fiddle with the settings, even the tone mapping ones. I managed to get the lighting indoors I want, it's the light making the outside look like a supernova I don't want. So, I had to use the ceiling lights to compensate for a darker outside. Using lights out of the windows is another option, and I'm currently messing around with that.
I have also had a look at the sun-sky settings. I can get some decent lighting there, but there is a void as there is no HDRI but I can just use my walls with images on them. I'd go with that option but it sky rockets the rendering times.
But thanks for the help and advice though.
@metaldragonman
As I said already don't think about eyes think about cameras. A camera can only use the available light so it will either be set for the outside which makes the inside dark; or the inside and the outside is washed out. To balance it then you WILL have to add interior lights there is no getting away from that. Try a camera if you can. Set it for a dark corner in your house and take a picture with a window in the scene. The outside will be washed out. put a light in the corner and set the camera for the window and take the picture, the corner will now show up.