How to exclude HDRI from lighting certain objects

[serjeant]

Hi,
In V-ray when we used HDRI with dome light we can excluded some objects from Light setting , an example using same HDRI to lightening interior and exterior. increasing HDRI multiplier will lighting interior good but at same time it can be out exposure for outdoor, so usually we can use two Dome light , one to lighting the outdoor area and one for interior with different multiplier,
is there any solution do achieve this way in Corona.   
appreciate your help

[TomG]

You can use the Direct Visibility Override - see https://coronarenderer.freshdesk.com/support/solutions/articles/5000501978 ("Environment Overrides")

[serjeant]

Thank you very mush TomG for your reply,
This way look really nice, but I'm not sure if this Solve the issue 100 % . bcs i see during material slot, We can specify another HDRI for certain objects which has that material, but in material map rollout there is only Reflect BG override and Refract BG override , this can control reflection and refraction, but what about generate lighting, There is no slot to tell this material to get only light from second HDRI, still didn't understand how use HDRI 1 to generate light in the interior and use HDRI 2 to generate only light for outdoor objects like boundary wall and pool , bcs usually we need to increase mult of HDRI more to get light perfect inside but most of the time that will burn outside the scene like pool and outdoor sitting, i hope i explain my issue. is Direct Visibility override slot can control that, but how to include that slot to lighting certain object only ..

[TomG]

Ah so you are not talking about having one HDRI shown as the visible background, and another used for lighting, but for one HDRI to be used to light one group of objects, and another HDRI to light another group of objects?

If so, you'd have to do some work in post - you can set up multiple HDRIs, and use LightMix to swap between them, so you would just need to render once. Once done save one version with one HDRI lighting everything, one with another HDRI lighting everything (from the VFB, or from the Corona Image Editor), and then use masks to composite those two different versions in image editing app of choice!

See https://coronarenderer.freshdesk.com/support/solutions/articles/12000057961-how-to-set-up-multiple-suns-environments for how to use the multiple suns and environments.

[serjeant]

I will follow this way, hope in future will add new option in Corona can provide easier way like dome or else to control that ,, 
Thank you again for taking time to reply my question,

[James Vella]

I agree with TomG with the composite method for this particular workflow.

However you could also fake the bounces by putting window lights for secondary bounce thus giving you a built in solution (wont be the same but can be effective).

[sprayer]

Why not to use just exposure on camera?

[James Vella]

Why not to use just exposure on camera?

This too. I actually thought thats what Tom also meant by the compositing method, either mixing 2 hdri or 2 images at different exposures. Similar to how you would do a HDRI merge in photography.

[madoarceo]

Why not to use just exposure on camera?

This too. I actually thought thats what Tom also meant by the compositing method, either mixing 2 hdri or 2 images at different exposures. Similar to how you would do a HDRI merge in photography.

Hi! I'm currently trying to figure out pretty much the same thing. Would you mind explaining further on this method? I'd really appreciate it.

I'm trying to have separate lighting for an interior scene where the room is lit separately from the trees in the background through the windows. I'm not getting satisfactory lighting results while the trees affect the lighting of the room.

[James Vella]

This seems to be a different issue than the OP. I think maru provided a solution for you that would suit the situation in your separate thread https://forum.corona-renderer.com/index.php?topic=26362.0;topicseen.

What I am proposing above is basically similar to what sprayer mentioned, render the interior at the desired exposure and then use a mask of the glass to lower the exposure of the exterior (in post production). Or if you use a pass management system like vexus/rpm you can just have 2 separate renders at different exposures (which could work in your case too especially if you dont want the trees to interfere with your lighting).