HDRI Sky System

HDRI Sky System in Omniarch allows to light scenes using High Dynamic Range Images (HDRI). This system sources directional light and global illumination from the loaded HDRI image, enabling realistic ambient lighting and reflections based on scanned real world environments.

HDRI Sky System can be accessed by clicking on the Clear Sphere Icon located in the Main Toolbar on the left edge of the interface.

HDRI Cubemap Import

To import a HDRI Cubemap, click the Sphere Thumbnail at the top of the panel. This opens a file browser popup window for HDRI Cubemap selection.

Currently, Omniarch only supports only .HDR cubemap format. Future updates will provide support for other cubemap formats. 

HDRI Parameters

• Intensity – Adjusts the overall brightness of the HDRI lighting. Higher values increase global illumination of the HDRI.
• Size – Defines the size of the HDRI sky dome projection. Higher values can help illuminate the scene properly. Low values can make dome smaller than the scene itself, making it unlit.
• Rotation – Rotates the HDRI environment around the Z axis, allowing control over the direction of lighting and backdrop image position.
• Projection Center – Manual position of HDRI cubemap using projection origin XYZ axis parameters.
• Use Camera Projection – When enabled, the HDRI aligns with the camera’s perspective rather than being fixed in world space. Useful for fixed-angle renders or immersive visuals.
• Lighting Distance Factor – Range of HDRI lighting falloff in the scene. Lower values keep lighting more local, while higher values allow broader ambient spread.
• Sky Light Leaking – Amount of ambient light bleed into interiors. Higher values may reduce shadows in overly dark areas, but can quickly wash out the light/shadow balance in the scene.

Only one sky system can be active at a time, either the Dynamic Sky System or the HDRI Sky System.