Basic Library Version: 9

Sky Object

1. General Description

Sky Object is used to simulate the diffuse light effect of the sky.
It consists of distant lights distributed in a hemispherical array.

2. Parameters

The input parameters of this object are:

Name Type Default Effects Description
A Length 1 2D / 3D Not used
B Length 1 3D Not used
C Boolean 1 3D Switch on / off the light source
D RGB 0.81 3D Red colour component
E RGB 0.89 3D Green colour component
F RGB 0.99 3D Blue colour component
G Intensity 50 3D Intensity of the Sky Light
ZZYZX Length 1 - Not used
AC_show2DHotspotsIn3D Boolean 0 - Not used
gs_lwa_lattitude_res Integer 3 3D The number of latitudinal lines used in placing light sources. Available values: >=1
gs_lwa_longitude_res Integer 6 3D The number of longitudinal lines used in placing light sources. Available values: >=3
gs_lwa_num_lights Integer 11 - Informs the user from the number of generated light sources.
gs_lwa_cast_shadows Boolean 1 3D Shadow casting on / off.
gs_lwa_soft_shadows Boolean 1 3D Shadow softness on / off.
gs_lwa_shadow_quality Integer 2 3D Quality of the shadows. Available values: 0 - 5
gs_lwa_set_sun_position Boolean 0 2D / 3D Set Sun Position Manually
gs_lwa_sun_azimuth Angle 0 2D / 3D Sun Azimuth - If gs_lwa_set_sun_position = 0 then this parameter use the GLOB_SUN_AZIMUTH global.
gs_lwa_sun_altitude Angle -1 3D Sun Altitude - If gs_lwa_set_sun_position = 0 then this parameter use the GLOB_SUN_ALTITUDE global.
gs_cont_pen Pen 10 2D / 3D Object contour pen

Longitudinal and Latitudinal Resolution

Longitude and latitude resolution parameters are used to specify the number of the generated light sources to represent the sky.
Latitude resolution equals the number of latitudinal lines on the hemisphere.
Number of longitudinal lines is measured on the first latitudinal line (the nearest to the equator). The number of longitudes (eg. light sources) along the rest of the latitudinal lines is decreased to guarantee the equal light distribution.

Sample position of lights

Soft and Hard Shadows

This parameter is used to specify whether hard-edged shadows or soft-edged shadows are created. Effective if gs_lwa_cast_shadows is on.

Shadow Quality

The parameter defines the quality of the soft shadows cast by the sky. Available values are integer numbers in the range [0 - 5]. The default is 2. It maps the following LightWorks® shader arguments:

  • LWA_LIdistant_shadowresol - it is mapped to the range 128 - 4096 exponentially
  • LWA_LIdistant_shadowquality - it is mapped to the range 4 - 9 linearly

3. Usage

Place the Sky Object just anywhere in the plan.
Note that the integrated LightWorks® rendering doesn't give a proper image quality in case the 3D data stucture generated from a selection (eg. with the Arrow Tool or with the Marque Tool) and this selection does not contain the Sky Object.

The LightWorks ® API is copyright (C) 1999,2000-2004 LightWork ® Design Ltd. All Rights Reserved.

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