Lighting tab

The Lighting tab allows you to create, manipulate, save/load and animate lighting configurations. Lighting configurations are stored separately from your scene in XML files with a .lights extension.

Example lighting configurations are supplied with the example assets for the SDK. The lighting configuration code uses the GeoEn2Support library, which is shipped as source with the SDK, if you wish to export your own lighting setups into our format.

When you first load a scene, for example MyScene, GeoRadiosity checks whether a MyScene_default.lights file exists in the root directory of the asset. If this file exists, GeoRadiosity loads it as the default light configuration. If one does not exist, GeoRadiosity creates a basic default light configuration with a single directional light.

The circular widget in the 3D view is a light position / rotation editing control. The control for a directional light is always shown at this location on screen.

Press the spacebar to toggle between the rotation and translation widgets.

Controls for point/spotlights are shown in the scene at the light source, as shown below:

Some of the options available on the Lighting tab are common to all light types. Others vary depending on the type of light selected.

Light Type	Option	Description
All	Load light config	Load a pre-existing *.lights file.
All	Save light config	Save the current lighting setup to a *.lights file.
All	Add spotlight	Add a spotlight.
All	Add pointlight	Add a pointlight.
All	Add directional	Add a directional light. GeoRadiosity can display only one directional light at a time.
All	Add arealight	Add an area light. This functionality is currently available for baking only. For details, see the Area Lights section on Static Lightmap Baking.
All	Add frustumlight	Add a frustum light.
All	Add boxspotlight	Add a box spot light.
Spotlight, pointlight, arealight, frustumlight and boxspotlight	Duplicate selected	Duplicate the selected light.
All	Remove selected	Remove the selected light.
All	Light casts shadows	Toggle whether the selected light casts shadows. There are some platform differences in shadowing support. See the table below for more details.
Spotlight	Load projection image	Load an image file to be used as a spotlight projection. Only available when a spotlight is selected.
Spotlight	Clear projection image	Remove a projection image from the scene.
All	Colour space (RGB or HSL)	Edit the colour of the selected light in RGB or HSL (Hue/Saturation/Luminance)
All	Light intensity	Change the intensity of the selected light.
All	Radiosity scale	Change the radiosity multiplier for the selected light.
Directional light	Directional spread	Adjust the apparent spread of the directional light for baked soft shadows (swept angle of radius of a circle on the infinite sphere).
Directional light	Shadow map max	Set the maximum distance plane of the cascade shadow maps. Other planes are at 10% and 35% of this.
Spotlight	Light inner cone	Adjust the inner cone of the selected light.
Spotlight	Light outer cone	Adjust the outer cone of the selected light.
Spotlight	Shadow near plane	Change the near plane shadow casting distance of the light.
Spotlight, pointlight	Intensity radius	The light has the given intensity at or inside this radius. Outside this radius, the light contribution attenuates with the reciprocal of squared distance down to 0 at the light cutoff distance value.
Spotlight, pointlight	Light cutoff distance	Maximum distance for the influence of the light. Beyond this distance the contribution is 0.
Spotlight, pointlight	Epsilon	Adjust the epsilon value to push shadows away from the surface.
Spotlight, pointlight	Soft shadow radius	Set the radius of the light for baked soft shadows.
Arealight	Rectangle width	Set the width of the rectangular area light.
Arealight	Rectangle height	Set the height of the rectangular area light.
Frustumlight and boxspotlight	Second inner cone	Set the inner bright angle of the light cone (in radians).
Frustumlight and boxspotlight	Second outer cone	Set the outer edge angle of the light cone (in radians).
All	Baked light	Tag the selected light for baking. For more information, see 2 - Static lightmap baking.
All	Shadow bias	Bias for depth comparison in shadow test for baking direct lighting.
All	Set environment	Add an environment cubemap. The cubemap has to be a DirectDraw Surface (DDS) cubemap file in A8R8G8B8, A8B8G8R8 or A16B16G16R16F format complete with all mip levels available in the DDS file. If you load a cubemap but do not see any illumination from the environment, you should double check the format is correct and that all mip levels exist.
All	Intensity	Set the intensity of the environment radiosity lighting.
All	Indirect specular multiplier	Adjust the global indirect specular multiplier for the Enlighten Directional Irradiance technique.
All	Normal map multiplier	Set the global multiplier for normal map deviation.
All	Force dynamic lighting	Force all lights to be rendered dynamically, ignoring baking settings. For more information, see 2 - Static lightmap baking.
All	Set all baked	Tag all lights for baking. For more information, see 2 - Static lightmap baking.
All	Set all dynamic	Set all lights as dynamic. No lights will be baked. For more information, see 2 - Static lightmap baking.
All	Bake	Bake all lights that have been tagged using either the Baked Light or Set All Baked controls. For more information, see 2 - Static lightmap baking.
All	Show light volumes	Toggle the rendering of light volumes.
All	Lock transforms	Prevent the selected light from being edited.
Spotlight, pointlight, and arealight	XYZ / Rotation	Toggle a spotlight or pointlight widget from Translation edit mode to Rotation editing. Alternatively, press the space bar.
All	World / Local	Toggle light position widgets between world-space coordinates and local light-space coordinates.
All	Light interpolation time	Set the duration for the interpolation between different light configurations.

Lighting notes

GeoRadiosity has some differences in how it handles lighting, particularly shadowing across the platforms. This is separate to the functionality the Enlighten runtime provides. The differences between the platforms are summarised in the table below.

Light Type	Rendered?	Casts shadows in GeoRadiosity?	Casts shadows in bounce lighting?	Notes
Spot light	Yes	Yes	Yes
Point light	Yes	Yes	Yes, except in GeoRadiosity	While possible, we do not shadow the input lighting for point lights in GeoRadiosity.
Directional light	Yes	Yes	Yes	Directional light visibility for Enlighten handled by the precomputed directional visibility data.
Environment light	Yes	N/A - lighting handled by Enlighten	Yes, part of Enlighten	Both the direct and bounce lighting is handled by Enlighten. GeoRadiosity simply displays the environment as a cubemap around the scene.
Rectangular (area) lights	Yes	No	Yes, but the visibility is approximated by a spot light and may not match the baked result exactly	The Enlighten API accepts area lights on all platforms, but they are skipped on non-PC platforms.
Frustum light	No - Indirect lighting only	N/A	Yes	Exposed for the purpose of testing the indirect lighting, but no dynamic direct rendering or baking support exists.
Box spot light	No - Indirect lighting only	N/A	Yes	Exposed for the purpose of testing the indirect lighting, but no dynamic direct rendering or baking support exists.