Lighting Settings


Lighting settings allow you to customize the environment of your flight. Adjusting the light options can enhance the flying experience by emphasizing certain light-dependent aspects. For example, shadows being cast will allow the pilot to anticipate flying conditions in the different forms of light.


Lighting in Prepar3D consists of two sections: Lighting and Shadows.


Lighting

Lighting includes HDR Lighting, dynamic lighting, Landing-light options, and lens flare.

HDR

High-Dynamic-Range lighting, or HDR, displays more realistic lighting with an increased level of detail. HDR lighting renders a more detailed scene by using light calculations done with a larger dynamic range. This appears to the user as crisper light, natural light reflections of the sunbeams and rays, as well as moonlight on the surrounding atmosphere. With HDR enabled brightness, bloom, and saturation can also be modified offering greater control of the final image.

Using HDR
Select the "HDR Lighting" check box in the Lighting tab of the Display Settings. By default, HDR is enabled.

Brightness

Adjust this slider to control the overall brightness of the scene. Requires HDR.

Light Bloom

Objects in direct sunlight are subject to exposure effects, making them look washed out. Adjust the Bloom level by moving the slider left and right to decrease or increase it. Requires HDR.

Saturation

Adjust this slider to control the color saturation of the scene. Requires HDR.

Dynamic Reflections

Makes reflections more realistic by replacing the static global environment map with a real-time environment map based on the camera. The resolution of the environment map doubles each quality step starting at 128 and ends at 1024. The types of objects that reflect at different settings are outlined below.

Low: basic world features (ex: terrain, sky, water)
Medium: taxiway and runway features)
High: autogen buildings and air features (ex: stars, clouds)
Ultra: details (ex: particles, vegetation)

Landing-Lights

Landing-lights can be used in low-lit times of the day in order to illuminate the runway that the pilot will land on.

Lens Flare

When the sun comes into direct view, the glare causes streaks of light called lens flares (like what you see when shooting a camera into bright light). This is beneficial for training when using an external camera view.


Shadows

Shadows are a new addition to Prepar3D that will add to the overall training experience. There are several settings that customize the user's flying experience.

Shadow Map Count

Shadow map count attributes to the quality and frequency of the rendered shadows. Shadow map count ranges from Low to Ultra. By default, it is set to "Medium".

Enable Terrain to Receive Shadows

This feature enables the terrain to receive shadows. If this is enabled, there are two options to determine the appearance of the received shadows:

  1. Terrain Shadow Cast Distance
  2. The terrain shadow cast distance is the largest distance that the terrain shadow will render out starting at the player's view origin. This distance can be set up to 80,000 meters.
  3. Cloud Shadow Cast Distance
  4. The cloud shadow cast distance is the largest distance that the cloud shadows will render out starting at the player's view origin. This distance can be set up to 80,000 meters.

Object Shadow Cast Distance

The object shadow cast distance ranges from 0 to 12,000 meters. This is the distance The settings allow you to choose which objects you want to cast or receive objects. The list is below:

Each object has the option for the shadow to be cast by the object type or to be a recipient of shadows. This allows the user to customize which shadows are displayed in the simulated view while having greater control over the overall performance of the software. NoShadow Flagged Content will respect 3rd party content shadow preferences.


Advanced Settings

There are advanced properties that can be adjusted from the Prepar3D configuration file found in %APPDATA%\Lockheed Martin\Prepar3D v3\Prepar3D.cfg

SHADOW_NUM_CASCADES_LOW
SHADOW_NUM_CASCADES_MID
SHADOW_NUM_CASCADES_HIGH
SHADOW_NUM_CASCADES_ULTRA
GROUND_SHADOW_TEXTURE_SIZE
CLOUD_SHADOW_TEXTURE_SIZE
SHADOW_LOG_PARTITION_LOW
SHADOW_LOG_PARTITION_MID
SHADOW_LOG_PARTITION_HIGH
SHADOW_LOG_PARTITION_ULTRA
HDR_BLOOM_THRESHOLD
HDR_BLOOM_MAGNITUDE
HDR_BLOOM_BLUR_SIGMA
TONEMAP_DAY_EXPOSURE_KEY
TONEMAP_NIGHT_EXPOSURE_KEY
HDR_BRIGHTNESS
HDR_SATURATION
ADAPTATION_RATE_SCALAR
HDR_BLOOM_EMISSIVE_SCALAR
HDR_BLOOM_SPECULAR_SCALAR
HDR_BLOOM_MODALPHA_SCALAR
HDR_BLOOM_COPY_SCALAR

The following properties can be adjusted to the user's specifications: Cascades and Log Partition.

Cascades

A cascade is a small area that encompasses the field in the player's view. This value can be between 2 and 12. At a value of 2 cascades, one cascade displays detailed shadows close up, and the rest of the shadows are encompassed in the second, so they are less detailed further away from the view origin. On the other hand, the more cascades that are added, the more detailed the shadows have to distribute across the player's view. Twelve cascades gives the highest ability to create detailed shadows at farther distances.

Shadows

Shadow textures for the ground and cloud size can be adjusted. The recommended values are values of 2 between 256 and 8096.

Log Partition

The log partition value can take on a value between 1.00 and 0.00, 1.00 provides more detail close up and 0.00 distributes detail further away.

Below is a juxtaposition of the five shadow settings with adjusted settings.


OffLowMediumHighUltra

Bloom

The HDR bloom threshold, magnitude, blur sigma,and material bloom scalars can be adjusted. The threshold and magnitude is recommended to be set between 0 and 10 and bloom blur sigma should be set between 0 and 1. The bloom threshold sets a limit for how bright the bloom can be, and the magnitude adjusts that brightness level. The blur sigma determines the level of sharpness that the environment is set to. It is an approxmiation of how much the image should 'spread' or blur to. The emissive, specular, mod alpha and copy scalar values scale the materials flagged to support bloom to better distinguish materials flagged to bloom when HDR is enabled. These values are recommended to be between 0 and 10.

Exposure

Exposure for both day and night can be adjusted. These values are between 0 and 1. The day and night exposure allow the level of light to be adjusted based on user preference.

Eye Adaptation

The eye adaptation rate can be modified by ADAPTATION_RATE_SCALAR to control the speed at which the adaptation transitions between bright and light environments.