Properties for Spot Lights

This page describes the configuration settings exposed for spot lights in the eRnsT interface.

setting	description	savable?
Transform	The properties in the Transform group define the position, orientation and scaling of the light source along each axis. These values are expressed in world space.	Yes
Enable	Determines whether or not the light is active. You can use this setting to disable a light temporarily if you want to test the effect of removing the light from the scene without permanently deleting it.	No
Color	Determines the color of the light radiated from the light source. The value you set here is also affected by the Intensity setting.	Yes
Intensity	Determines the intensity of the light radiated from the light source. The default value of 1 produces light at the full value of the Color setting. Lower values dampen the strength of the color proportionately, and higher values push the color toward white. A value of 0 effectively disables the light source.	Yes
Direct Light Scale	Applies a scaling factor to the strength of the direct light rays emanating from the light source. You can use this setting to tweak the strength of the direct light relative to the indirect light.	Yes
Indirect Light Scale	Applies a scaling factor to the strength of the indirect light rays emanating from the light source. You can use this setting to tweak the strength of the indirect light relative to the direct light.	Yes
Bake Direct Light	Determines whether or not the direct light from this source is baked to the lightmap. If you set this value to false, the direct light component is rendered in the 3D view using real-time shadow mapping. Indirect light from the source is always baked to the lightmap.	No

Light Stats

The settings in the Light Stats group determine when the light source contributes to the overall lighting.

setting	description	savable?
Visible for Eye	Determines whether or not the light source gives a direct light contribution.	Yes
Visible for Refl	Determines whether or not the light contributes to rays that have been reflected.	Yes
Visible for Refr	Determines whether or not the light contributes to rays that have been refracted.	Yes
Visible for GI	Determines whether or not this source contributes to the indirect light in the scene.	Yes

Falloff

The settings in the Falloff group control the way the light from this source diminishes with distance.

setting	description	savable?
Type	Determines the type of algorithm used to diminish the light as the distance to the source increases. The choice you make here determines the way the other settings in this group are interpreted. This setting offers the following options: Exponent: calculates falloff based purely on the distance from the source, and clips any contributions at a distance greater than the value of the Range setting. Max Range: calculates falloff based on the value of the Range setting so that the light diminishes gracefully as it approaches the Range threshold. Polynomial: allows you to specify three coefficients (Constant, Linear, and Quadratic) that are used to calculate the falloff. The equation used is as follows, where r represents the distance to the light source: falloff = ( 1 / (Constant + Linear * r + Quadratic * r²))	Yes
Range	Specifies the maximum range of the light emitted by this source when the Type setting is set to Exponent or Max Range.	Yes
Exponent	Specifies the rate of falloff when the Type setting is set to Exponent or Max Range. A value of 0.0 gives no falloff, 1.0 gives linear falloff, 2.0 gives quadratic falloff, etc.	Yes
Clamp	Determines whether or not falloff calculations are clamped to a maximum of 1.0 in the immediate region of the light source. Enabling this setting may be helpful for point lights that are placed close to walls or other objects, to avoid washing out details in the object textures.	Yes
Constant	Specifies the constant coefficient used to calculate falloff when the Type setting is set to Polynomial.	Yes
Linear	Specifies the linear coefficient used to calculate falloff when the Type setting is set to Polynomial.	Yes
Quadratic	Specifies the quadratic coefficient used to calculate falloff when the Type setting is set to Polynomial.	Yes

Light Cone

The settings in the Light Cone group determine the size and shape of a spot light's cone and penumbra.

setting	description	savable?
Cone Angle	Defines the angle, in degrees, from the center of the cone to its edge. Therefore, the total spread of the cone is twice this value.	Yes
Penumbra Angle	Specifies an additional angle from the edge of the spot cone within which the light will gradually fade into shadow. A positive value means that the limit of the illumination emitted by the spot light will be at an angle of Cone Angle + Penumbra Angle. A negative value means that the shadow will begin at an angle of Cone Angle - Penumbra Angle, and will fall off gradually up to the limit sest by Cone Angle.	Yes
Penumbra Exponent	Determines the rate of falloff for the illumination in the penumbra as the angle from the center of the cone increases. A value of 0.0 gives no falloff, 1.0 gives linear falloff, 2.0 gives quadratic falloff, etc.	Yes
Gobo Texture	Displays the file name of the texture set up for this light source, if any. This value is read-only; textures can only be assigned to spot lights using the Beast API.	No

Shadows

The settings in the Shadows group control whether or not the light casts shadows, and how those shadows are calculated.

setting	description	savable?
Cast Shadows	Determines whether or not the direct light from this source casts shadows when it hits physical objects in the scene.	Yes
Shadow Radius	Specifies the radius of this light source when considering it as a shadow caster. Larger values produce more diffuse shadows, smaller values produce sharper shadows.	Yes