Skylight Environment

Skylight

VRED provides two kinds of environment nodes. One gets it representation and lighting behavior from a texture file (sphere) and the other one simulates the position of the sun depending on world time and location (skylight).

A skylight environment provides physically correct simulated lighting, depending on world time and location. Skylights are procedurally generated Sphere Environment materials.

Preview Image Skylight

Every environment that is contained within the project file got its representation from within the environment library.

  • LMB selects an environment
  • RMB opens the context menu
  • Single LMB on a selected environment enables renaming
  • Double LMB sets the selected environment material to be used as current

The Skylight provides an interactive preview image that allows you to quickly change the sun position. The yellow curve within the preview image depicts the sun path from sunrise to sunset at the currently set date and location. You can set the sun position represented by a circle by clicking the sun path. The preview image includes labels of the four cardinal directions (N = North, E = East, S = South, W = West). If the current location is on the northern hemisphere, South is the centered direction; for locations in the southern hemisphere, North is the centered direction.

Skylight Material

  • Environment - An environment node provides a textured surrounding with shadow plane on its ground. Its texture affects the representation of all scene-related materials. The dome and shadow plane are automatically generated.

  • Resolution - Sets the resolution of the procedural environment texture. A higher-quality yields higher generation time for the environment, but might be necessary in Precomputed Illumination mode with an animated sun. Choose between Interactive (Low), Medium or High Quality.

  • Glossy Quality - Sets the glossiness of the skylight material. This value defines the quality for the Precomputed Glossy IBL. It is also used for the Precomputed Raytracing Mode, but not for Full Global Illumination.

  • Environment Geometry - Sets the shape of the geometry used for the skylight environment. Choose from:

  • Custom - Uses the loaded file as the shape for the environment. Use this for unconventionally-shaped environments.

  • Dome - Uses a dome for the environment. Use this for outdoor spaces.

  • Sphere - Uses a sperical shape for the environment.

  • Cube - Uses a box for the environment. Use this for rectangular spaces, such as a garage or showroom.

  • Geometry File - Loads a custom file as the environment geometry.

  • Is Visible - Toggles the primary visibility of the environment. An environment material set to not be visible can still illuminate scene objects, if it is enabled to be used as lightsource, and can still be used for specular reflections in Raytracing.

  • Flip Inside Out - Flips the normals of the environment sphere. This changes whether the environment geometry can be viewed from the inside or outside.

  • Shadow Plane Visible - Displays the shadow plane.

  • Show Compass - Displays a compass in the render window for the currently selected skylight material. The compass is positioned at the environment’s center and oriented according to the environment rotation (see Transformation).

Shadows and Illumination

  • Shadow Lightsources - Sets the number of explicit light sources. There are 256 light sources available.

  • Use Lightsources Only - When selected, uses only the specified light sources for casting environment shadows, when enabled. At least one lightsource must be entered in the Shadow Lightsources option for results. In the Raytracing Settings tab, set Illumination to Full Sphere to get illumination from the floor.

  • Material Shadow Intensity - Sets the shadow intensity of the generated lightsources on BRDF-based materials.

  • Ground Shadow Intensity - Sets the shadow intensity of the ground shadows.

  • Map Filter Radius - Sets the map filter radius.

  • Map Resolution - Sets the quality of OpenGL shadow maps. Higher values increase the quality.

Sky and Sun

  • Sky Model - Provides two different sky models - Realistic and Artistic. The artistic sky model produces more reddish and colorful skies; especially for sunrise/sunsets.

  • Sky Turbidity - Sets the amount of particulate in the sky. Control the amount of haze in the atmosphere. Low values correspond to a clear blue sky. Increased values add dust to the sky. The default value of 3.0 is a clear sky in a temperate climate. The maximum value of 10.0 yields a hazy sky.

  • Sun Scale - Creates sunlight-generated shadows with hard edges near objects that casts them. The farther the distance from the object, the softer are the shadow's edges. Reducing Sun Scale extends the shadow's distance creates harder edges. Control the size of the sun. The default value 1.0 corresponds to the actual size of the sun, seen from the earth. The sun is drawn as a filled circle within the sky environment. Increase the sun scale to get softer shadows with raytracing.

  • Sun Visible in Specular Reflections - Defines whether the sun of this skylight material is visible in all specular reflections in the scene, for example, on clear coat.

  • Use Mirrored Sky as Ground - Uses the mirrored upper hemisphere (sky without sun) as the lower hemisphere (ground).

  • Ground Color - Changes the brightness at ground level. Click the color field to the right to open the Color Chooser and define a custom color. Set the color for the single-colored ground in the lower hemisphere if Use Mirrored Sky as Ground is not selected.

Note:

When using the Realistic sky model, the ground color serves as a ground albedo which influences the tint of the sky.

Date and Time

  • Date - Sets date of the simulation to determine the sun's path, using the Local Time, Date, and Location settings to compute the sun's position.

  • Today - Changes the date of the simulation to today, setting the date to the current operation system date.

  • Local Time - Changes the time of the simulation to the current date, using Local Time, Date, and Location settings to compute the sun's position.

  • Now - Sets the time to the current operation system local time.

Location

Adopts the clicked map position for the sunlight simulation. An orange point on top of the map indicates selection. Another possibility to define this location using the text field directly below the map. It requires a city name on live-search supported input. A yellow point on the map previews occurrence. Confirming input converts the yellow point to orange when the simulation has adopted the new location.

  • Longitude/Latitude - Sets the location to these geographic coordinates in decimal degrees.

  • Time Zone - Sets the time zone using the time difference to UTC (Coordinated Universal Time). It is automatically estimated from the closest city to the given geographic coordinates.

  • DST - Enables/disables daylight saving time. Specify whether there is daylight saving time at the current location on the current date because this information is not retrieved automatically.

  • Closest City - Names the city closest to the given geographic coordinates and uses this city‘s current time zone.

  • Location Search - Retrieve latitudinal and longitudingal data from a database of over 22,000 cities. You may also enter a country name and choose a city from the popup list.

Color Correction

  • Map RGB(1.1.1) to - Only available when Photometric Parameters is enabled. Maps the RBG values to the option selected. Select from 1, 100, 10000 (realistic), or a custom value of cd/meters squared.

  • Luminance Mapping - Only available when Photometric Parameters is enabled. Defines what an RGB white color in the image refers to. Since there is no definition of what a white color in an HDR file actually represents, this is a way to baseline different HDRs to the same level.

  • Exposure - Sets the scaling factor on the HDR results. It controls the influence about lighting and reflection from the environment node to any object within the scene. A threshold from 1.0 interprets the texture exactly like it is; a value below/above darkens/lightens all objects. Set the HDR image’s exposure level. The higher the exposure level, the longer the series of shutter cycles which are used to calculate the image’s light intensity.

  • White Balance - Sets the camera's white balancing color temperature. Lower values balance the camera to a lower color temperature and therefore create cooler (bluish) colors. A higher value balances the camera to a higher color temperature and produces a warmer (yellowish) color. 6500K is a sRGB standard for most monitors.

  • Hue-Shift - Shifts all colors in the HDR image uniformly through the hue color range, setting the hue shift in degrees.

  • Contrast - Separates the light and dark color values further from each other, setting the color contrast.

  • Brightness - Sets the scaling factor that is as part of the color correction, by applying a color correction matrix, raising the color value of the whole HDR image, and setting the color brightness. It is applied to the image before the scaling by the exposure.

  • Saturation - Sets the HDR image’s saturation.

  • Reflected Saturation - Sets the HDR image’s saturation when the HDR image reflects in any surface.

Transformation

Sets the source of spherical projection of the Skylight using the transformation parameters.

  • Environment Size - Sets the size of the projection. Textures default to infinite projection depth and cover the entire object. You can restrict the texture to one side of the object by limiting the range of the projection. Changing the Z value of the projection size from zero (infinite) to another value achieves the restriction.

  • Center X, Y, Z - Sets the x, y, and z coordinates for the center of the projection.

  • Rotate X, Y, Z - Sets the x, y, and z rotation for the projection plane.

  • Scale X, Y, Z - Sets the x, y, and z scale factor for the projection plane. With the scale value, the image projection can be stretched and squashed on any axis.

  • Manipulate - Provides texture manipulator in the render window to manipulate the environment in the scene, as you can do with other materials. With an environment selected in the Material Editor, click Manipulate to display a manipulator to rotate, scale, and translate your environment material interactively in the scene. When finished, click Manipulate again to disable it. This function also requires a selection in the Scenegraph.

    Manipulate button in the Environment Transformation section

  • Object Center - Sets the projection sphere’s center. To center the projection pivot automatically, select an object and press Get Center. The selected objects center is used as projection spheres pivot.

Raytracing

These settings take effect in Raytracing Mode only.

  • Is Visible in Reflections - Sets the visibility of the environment in reflections. For highly reflective materials in a scene, to turn off the reflection of the environment, disable Is Visible in Reflections.

  • Use as Light Source - Does not calculate diffuse or glossy illumination, when disabled. Only one visible environment should be used as light source, otherwise VRED does not know which environment to use as light source.

  • Use Accurate Geometry - When selected, uses the real environment geometry, for more accurate diffuse and glossy illumination in Precomputed+IBL and Full Global Illumination Mode (at the cost of a 20 to 25 percent performance hit compared to the default finite sphere environment). It is disabled by default, so all diffuse and glossy reflection calculations are based on the virtual sphere of the environment.

    Note:

    This option is only supported for diffuse and glossy environment reflections.

  • Emit Photon Caustics - Activates/deactivates Emit Caustics. Allows the HDR to emit caustics (light rays reflected or refracted by a curved surface or object or the projection of that onto another surface). Mode with caustics (Photon Tracing mode = Caustics + Indirect). Only supported in Full GI Illumination mode with caustics.

  • Filter Sampled Cuastics - Limits the energy for caustic ray paths to avoid excessive noise in path tracing.

  • Importance Map Quality - Adjusts the resolution of the importance map to the environment.

    Tip:

    The following Python scripts were added for working with importance maps: getImportanceMapQuality() and setInteractiveIblSamplingQuality(value).

  • Anisotropy - Sets the anisotropy value for texture filtering.

  • Material ID - Sets the ID of the material for Renderpasses rendering.

  • Shadowing - Defines the shadowing used for the environment shadows in the Illumination Mode, Precomputed+Shadows, for the shadows on the Shadow Material and for the shadow lightsources generated for the environment.

    • Upper Hemisphere - Generates shadows based on the upper hemisphere of the environment.

    • Full Sphere - Generates shadows based on the full environment sphere.

  • Override IBL Sampling Quality - If enabled, the setting overrides the global IBL Sampling quality for sampling the environment map.

    • Interactive - Sets interactive IBL sampling quality.

    • Still Frame - Sets still frame IBL sampling quality.

Icon Bar

Often required commands are accessible by an icon located directly below the material library.

Icon Bar)

Create Create - Opens a sub menu that provides for creating either an environment or skylight material.

Duplicate Duplicate - Creates an independent copy of the selected material.

Group Selection Group Selected - Groups environments selected in the Material Graph or Group Preview.

Select Nodes Select Nodes - Selects all nodes with the currently selected material applied.

Apply to Selected Nodes Apply to Selected Nodes - Applies the selected material to all selected nodes.

Remove Unused Materials Remove Unused Materials - Removes all unused materials from the Group Preview.

DeleteDelete - Deletes the selected material from the Group Preview.

Optimize Materials Optimize Materials - Converts material images to grayscale. This is to reduce file size and improve performance.