A type of Light Source that radiates in all directions from a specified point in 3D space.
Positional Light specifies a sphere of influence; only objects that are within this sphere can be affected. In addition, as with all Light Sources, only Primitive Geometry that are below the Aggregate Geometry that a Light Source is attached to will be affected if the apply_to_children field is true.
A Positional Light also has attenuation factor fields, used to calculate the attenuation based on distance from the light. Light intensity components (ambient, diffuse, and specular) are attenuated by the reciprocal of the attenuation quadratic (a + bd + cd**2), i.e., the formula for the final attenuation factor is:
1
--------------------------------------------------------------
[ constant_attenuation_factor +
(distance * linear_attenuation_factor) +
((distance squared) * quadratic_attenuation_factor) ]
If attenuation is not provided then the default factors (a=1.0, b=0.0,
c=0.0) are assumed, resulting in no attenuation; the light ends abruptly
at the edge of the sphere of influence.
| SE_BOOLEAN | apply_to_children; | (notes) |
|---|---|---|
| SE_BOOLEAN | override_positional_lights; | (notes) |
| SE_BOOLEAN | override_infinite_lights; | (notes) |
| SE_BOOLEAN | active_light_value; | (notes) |
| SE_FLOAT32 | radius; | (notes) |
|---|---|---|
| SE_FLOAT64 | constant_attenuation_factor; | (notes) |
| SE_FLOAT64 | linear_attenuation_factor; | (notes) |
| SE_FLOAT64 | quadratic_attenuation_factor; | (notes) |
3D position in 3 space. This will be affected by hierarchical transformations.
Flag to allow lights to limit their scope to only affecting their children. If apply_to_children is False then the light is assumed to apply globally.
Flag to reset the current cumulative definition of local Light_Sources If override_positional_lights is True then all Positional Light Sources in the current scope are cleared.
Flag to reset the current cumulative definition of Infinite Light_Sources. If override_infinite_lights is True then all Positional Light Sources in the current scope are cleared.
SE_TRUE = on, SE_FALSE = off this is the default/active state of the light
(in meters) The radius and position define the sphere of influence. This will be affected by hierarchical transformations.
Constant 'a' in the attenuation quadratic (a + bd + cd**2)
Constant 'b' in the attenuation quadratic (a + bd + cd**2)
Constant 'c' in the attenuation quadratic (a + bd + cd**2)