Download

Interior and exterior lighting balance

Hi,

Is it possible to have a balanced lighting between an exterior and an interior without auto exposure? I don’t want to use auto exposure to avoid seeing the terrace overexposed when you are inside and the interior too dark when you are outside. Is the a way to have a different postprocess volume that affects the camera even when you are not inside that volume?

Thank you

There’s post process material and/or blendables. I suggest doing some reading about those before delving into creating. Essentially the post proc material can be applied to the camera view somehow, but it needs to know when, so it has to be instructed to detect when in the interior. Possibly a trigger volume activated in a blueprint that has the post process material connected to the on trigger event, which is when the camera enters the trigger volume. Having a trigger volume for each of the areas, interior and exterior, is required. So it’s going to involve sizing a few or so trigger volumes for the exterior, and perhaps also for the interior to get the entire areas covered.

What are the auto exposure settings for the PPVs of the scene currently?

I wouldn’t say it is impossible but it is not easy. Eyes do adopt to different lighting. When the sun shines outside your eyes adjust their exposure to the brighter light. Post process volumes do the same. By design they only work when the player (camera) is inside the volume. The volume with the highest priority will have its settings applied. Having a trigger volume would pretty much be the same as extending the post process volume. You would need to be inside the trigger volume.

You certainly can improve your lighting inside so it is a bit closer to the outdoor lighting. Mabe try to use some rectangle lights in the windows with relative low intensity but a large range. You could also try to add some artificial lights in the kitchen. Then you can turn down the sun or sky light so both inside and outside lighting is a bit more similar.

When not in a PPV, the exposure overbrightens things by default and at closer viewing distances. How are the PPVs set up currently? as in, where are they positioned, what is the exposure set at, and what are the scale values? Blend Radius is a setting to decrease or increase the transition between two overlapping or nearby PPVs. So, if one PPV is inside another (such as the interior PPV is inside the larger, exterior PPV), then a Blend Radius of 100 would transition from the interior look to the exterior look across 100 cm around the inside PPV…when moving the camera from inside to outside. I tried something to solve your problem in a project I use for testing, and to get somewhat the effect you’re trying for, I created two PPVs. One is immediately surrounding the interior of a building, and has Auto Exposure set to Histogram mode (Compensation value 0, Min 2, Max 2), and the other is outside the building at about 40-60 cm (Unreal Units) from the interior on one side. It’s set to Basic mode (Compensation value 1, Min 2, Max 2), everything else default in exposure, and has RT fully disabled. When I go outside of those PPVs with the camera and look at the building within about 2000 from it, the over-brightening happens. It’s a transition from lit to looking like it has a giant spotlight on it. The reason I set the Min and Max values the same is to avoid that obvious transition and keep the exposure constant in the PPVs. It’s simply that the outside PPV is a bit lighter inside it and the interior PPV is a bit darker when inside it. A better approach would require skylight and / or directional light to be adjustable in a PPV, and for a PPV to be capable of referencing the area outside it along with changing properties of the target reference area if the camera is inside the source PPV. It could potentially be programmed with blueprints, but I don’t know how to do it. Perhaps by subtracting the volume space that the PPV contains from the whole scene, or a larger PPV surrounding the source one, and generating a reference to the result to target it for adjusting via the properties within the source PPV.