Interior Archviz lighting question

I’m hoping to get some recommendations from some people who have good experience lighting indoor arch viz scenes in cycles.

  • I’m using hdri (for lighting only) and a sun to help light the scene. It is a daylight scene. I can’t remove any walls to assist in lighting. Most of the rooms do have windows on at least 2 walls. Everything has been modeled to scale using imperial. Unfortunately the file size is giagantic so I can’t post the file.

-The aim is to get more realistic shadows with more contrast than what I am currently getting.

My first question is regarding the mix between HDRI strength settings and the sun strength settings. Is it best to leave the HDRI strength at say the default of 1.0 and just crank up the sun strength. Or is there some other kind of mix between the two strengths I should be trying.

I guess I would just like to get clarification on the mix of these 2 lighting elements, and if you could share what your initial settings you use, particularly regarding the sun strength , and sun size settings that would be great.

Hi, to get realistic shadows from a Sun you can set sun size to 0.005.
Cant say much about balance between sun and hdr.

For interior renders, use planes with an emission shader in every window hole, and disable the “camera” option in the “ray visibility” panel in the object properties so you don’t see it when rendering. You can combine that with a sun lamp if you want hard edge shadows coming from the sun.

Cheers, mib

@mib I forgot to mention that I am using those light planes in each window, but it some ways this may be contributing to some of my problem. So I did a little test … these are low rez renders (500 samples), no post processing at all.

@maraCZ Thank you for the links. I haven’t had a chance to read completely the second link, but it looks like some great information.
Most all of my diffuse shaders, I’m no higher than the default of .8

If you still want that warm sun indirect light you can simulate it with invisible plane mesh on the floor pointing up.

Just curious, how big of a plane mesh, and I am assuming you would use an emmission shader?

Image 1 - no window plane lights , sun,hdri, and some ies lamps. Notice those light rays you see on the chaise lounge and parts of the floor.

Image 2 This one same as above only with the window lights. I am assuming that window planes are somehow blocking the sun. The window lights do seem allow it be a little less noisy. But I really would like to see the sun similar to image 1. Is there anyway to make some type of node adjustment to do that?

Currently the window planes are just an emmission node, but I have both camera visability and transmission visibility disabled in the Ray visibility section.


Uncheck shadows in Ray visibility, to let sun pass through them.

Thanks marcoG_ita… man I just love that Earnes chair you did… top notch for sure.