Create realistic daylight through windows physical render

[JustJools]

Hi, I have been struggling trying to set up a realistic lighting situation so it reflects the reality of the property I am renovating. The downstairs has two windows either side of the house with a door in the middle and a balcony above on the second floor. in real life, just with two windows it is very dark inside and I am trying to emulate the lighting conditions to see what effect adding bigger windows and maybe a glass floor adds. 

 

I cannot seem to get the settings right. I am trying this in dusk light with a test room and one window and have turned down the 3d>Adjust sunlight to custom lux 100 with lamp at 1 lumen (to override the automatic light) but the light inside is much brighter than it should be. I have also tested the room without a window and it is no darker. How do I get accurate light settings?

 

I am trying with the lowest light settings as doing it with normal daylight settings there is too much light coming in illuminating through windows that doesn't match real life scenario.

 

 

[ConnorE]

Hey there,

 

What version of Home Designer are you using?

 

I tried this scenario using Home Designer 2025 and saw the same behavior you mentioned.

The issue is that when using the Physically Based rendering technique the system tries to balance the exposure of the scene as evenly as possible. That's why changing the intensity of the lamp and sun didn't do much to affect your scene.

 

I was able to get something close to what I think you're aiming for by using the Generated Sky for the backdrop, and turning down the Automatic Exposure and Brightness values in the Physically Based Rendering Technique Options.

The problem with this approach is that the setting affects the exposure of the entire scene. Meaning, the interior lights will also look drastically dimmer.

Also, when adding more windows you won't see a substantial change in brightness of the render unless you change the automatic exposure/brightness of the scene again. 

 

It seems that you can at least get the individual renders that you need by tweaking the exposure setting, but I'm not sure of a good way to do this in real-time.

Hope this helps a bit!

 

Edited October 1 by ConnorE
Added that I was using the Generated Sky for the backdrop

[JustJools]

Thanks for looking at this. I have HD 2024 so dont have the exposure settings. It's strange using dusk sunlight it doesn't accurately let light in through the windows. It automatically overlights the room when you enter, and you can see the light is dramatically brighter than outside (magical lighting). I have turned off the automatic light settings and added a lamp to override but it still automatically lights up the room, and seems no way to override this to use natural outside sunlight. It seems it's designed to be on or off in some generic way, designed first and foremost for best illustrative lighting conditions but not realism. 

 

The best way I have found to get close to the lighting conditions of my real life house is to use street lights outside but this is giving strange light paths across the floor not through windows.

 

 

[JustJools]

Finally got somewhere close using backdrop, as you suggested. Changing the sunlight settings makes no difference to the interior light so must be overriden by the backdrop. It's still too bright and should be an overcast day but this isn't bad, and I can work with this.

[ConnorE]

Glad you were able to get a solution!

I just double checked HD 2024, and if you're using the Physically Based Rendering Technique you should have access to the Exposure settings.

You can find it in Rendering Technique Options, which can also be launched by double-clicking the Physically Based button