High-level concept explanations, detailed tutorials, performance considerations, shortcuts and other useful content that aims to improve your Unreal Engine 4 development journey.
Currently, your scene lighting may be quite harsh with overexposure and lack of light in shadow cast areas. These factors can be mitigated as follows:
Since the directional light in the scene does not make use of bounced light (Ray Tracing will not be used in this instance), an artificial bounced light is required by using the Sky Light.
Add a Sky Light from the Modes panel.
Set the Location to [0, 0, 400] to hover the sky light above the level origin.
This will result in artificial bounced light in cast shadow areas.
Note that the default parameters are recommended and any adjustment should occur within the scene light sources rather than the sky light itself.
Moving the camera around the scene will result in automatic light exposure which may increase the difficulty of correctly balancing the scene lighting. A Post Process Volume allows for control of all light in the scene through a single controller.
Add a Post Process Volume from the Modes panel.
Set the Location to [0, 0, 0] to place the post process volume at the level origin.
Under the Lens section of the Details pane for the post process volume, enable the Min Brightness and Max Brightness options with respective values of 1.0 each. This enforces the standard light exposure within the volume constraints.
Under the Post Process Volume Settings section, enable the Infinite Extent (Unbound) option. This enforces the standard light exposure across the entire level bounds.
The scene is lacking a realistic looking sky.
Add a BP_Sky_Sphere from the Modes panel.
Set the Location to [0, 0, 0] to place the post process volume at the level origin.
The sky sphere offers optimal effects when linked to a directional light, as with atmospheric fog.
Under the Default section of the Details pane for the sky sphere, select the dropdown for the Directional Light Actor setting and select the directional light in the level.
Environmental lighting can be customised to a range of settings to meet the requirements of the level design. This is such an example:
Under the Light section of the Details pane for the directional light, set the Intensity setting to a value of 1.0 lux for a dusk-like effect.
Rotate the directional light to be at an appropriate angle for a dusk-like setting. Note that the sun spot does not update, and the sky sphere needs to be disabled temporarily to see the expected changes. Thereafter, re-enable the sky sphere and select the Refresh Material setting under the Details pane.
To enable sun rays from the sun spot, enable the Light Shaft Occlusion and Light Shaft Bloom settings under the Light Shafts section of the Details pane. To reduce the glaring effect, set the Sun Brightness setting to a value of 1.0 under the Default section in the Details pane of the sky sphere.
To add some lighting dynamism to scene, set the values of the Bloom Scale and Bloom Threshold settings to 0.55 and 0.15 respectively under the Light Shafts section in the Details pane of the directional light.