Question about changing the environment light intensity

[Matthew_Polewiak]

Hi,

I have recently made a model of my room using 3Ds Max and corona renderer. But I am having an issue with lighting. I used a random HDRI from polyheaven that somewhat looked like the area outside my window, as an environment, loading it through a corona bitmap. I rotated the environment so that the sun was on the same side as the window to the room, but the room was still very dark. I know I can change the camera exposure to increase the brightness but when I do that all of the light sources become overexposed. 

 The second render is how it looks with the room lights turned off and the scene only illuminated by the environment and some glowing interior elements.

The first render is the same but with exposure turned up to 4, the lighting looks much closer to how it is in real life but all of the direct light sources are overexposed.

Is there some environment brightness value that I wasn't able to find?

 

[darawork · Accepted solution]

Hi,

It looks tricky alright. You can always use the highlight compress spinner in the post tab to prevent areas where the light is burning. Another thing to check is the glass, just to make sure it is thin with no refraction. If you do an albedo element pass too, you can see if any materials in your scene are reflecting unnatural levels of light. 
Another thing to setup, if not already done, is a lightmix element, so as you can individually control all light emitters.
A tip I alway use is to never push each lightmix source amount over 1.0, to do so will simply multiply noise in the scene. Always bake your lighting to the scene, once you have your lightmix amounts set, by pressing the -> Scene button on the Corona VFB.

This is also an invaluable script to use for HDRI lighting in Corona Render:
https://moso-studio.com/quick-environment-script-v2/ It can really help out in tricky lighting situations. Balancing a Corona sun object with equal amounts of HDRI can sometimes be very useful to get great results.

In case you haven't watched this before, this is a very good tutorial/troubleshooting video:
https://www.youtube.com/watch?v=8CC5Gn431wA even when I think I have everything set up right, this video always helps spot something I might have missed.

Regards,

[Matthew_Polewiak]

 Do you know what should I do if my highlight compression settings are not in the post tab?

[Matthew_Polewiak]

 

I was able to get this result, which Is much better than what I got previously, by changing the environment intensity value in the lightmix to 5, and turning th exposure down to .5 (both from 1). It looks a lot better but it's noticeably still darker and more overexposed than in real life. 

[dgrehan · Accepted solution]

Hi,

Sorry, yeah, the Hightlight Compression is now called Reinhard highlight compression in later versions of Corona. I'm still using Corona 7 for work. There are some good tutorials here: https://rebusfarm.net/news/chaos-corona-tone-mapping-in-3ds-max-cinema4d

Also there is a good interior lighting tutorial here, it's pretty old though using an older version of Corona with 'Light Portals' which no longer exist, but there are some other good tutorials on that channel:

https://www.youtube.com/watch?v=YgAwLb1yt0U

It's looking good btw.

I find sometimes that if the materials are burning too much, you can lower the reflection colour of the material to something less than pure white, to a slightly grey colour. This might allow you to increase the general exposure without things burning out.

Doh, just realised I'm logged in with my other account. If this post is a solution, please mark my above post as the solution instead hehe

Regards,