HDR Environment Images Parameters

The Scenes tab in the Palette includes parameters that appear on two subtabs when you select an environment in the tab.

Upon import, the software preserves the brightness and gamma settings in the source HDR image. After import, you can change these settings and adjust the environment in the Scenes tab of the Palette.

Show Environment Image Shows/hides the environment image. Even when hiding an HDR environment image, the image still radiates light into the project and reflects off shiny surfaces. When you hide an environment image and a backplate, the background color is defined by the Background Color parameter in the Scenes tab.
Flatten Floor Flattens the floor of an environmental sphere. HDR images are spherical by default, with the equator corresponding to the imaginary level of the floor. Flattening the floor converts the environment sphere to a half-sphere. The image is re-mapped to the resulting half-sphere and the bottom becomes a visible floor.
Background Color Determines the background color of the 3D Viewport outside the environment sphere. Click the color to choose a new color.
Brightness Sets the luminance. Higher values increase brightness; lower values decrease it. Changes are made in real time.
Gamma Sets the contrast and brightness. Higher values decrease contrast and increase brightness; lower values increase contrast and decrease brightness. Changes are made in real time.
Size (meters) Sets the radius of the environmental sphere.
Height (meters) Vertically offsets the environment image relative to the world origin.
Rotation Rotates the environment, thereby changing the direction of light radiated by the environment image. Rotation is in degrees.
Flip Horizontal Flips the environment image horizontally (left/right) around a vertical axis in the center of the image.
Floor Reflection Sets the level of caustics from a physical light source on the artificial floor.

Caustics are patches of intense illumination caused by the refraction of light through a transparent object or the reflection of light from a reflective surface. An example is the shifting patterns of light and shade cast on the floor of a swimming pool on a sunny day.

Floor Roughness Sets the level of shadows from physical light sources on the artificial floor.
Floor Shadow Shows or hides shadows. The software calculates the shadows that each 3D model casts on itself, on other models, and on the floor. Showing shadows can impact performance due to the increased number of calculations required.

You can set the floor shadow to form from spot or point lights only if a floor plane is present.

Shadow Intensity Lightens or darkens the environment floor shadow.
Show Grid (In Preview) Shows or hides a grid in the XZ-plane.
The grid is visible only when Raytrace is off.