Graphisoft®

Basic Library Version: 16

Sun Object

  1. General Description
  2. Parameters
  3. Usage

1. General Description

Sun Object is used to simulate sun light with soft shadow edge in photorendering. It consists of distant lights distributed in a cone area.

The following examples show the rendering output with ArchiCAD's default sun and with Sun Object (the second image).

rendering with default sun - sharp shadow edges rendering with Sun Object - soft shadow edges

2. Parameters

The input parameters of this object are:

Name Type Default Affects 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 Sun Light
ZZYZX Length 1 - Not used
AC_show2DHotspotsIn3D Boolean 0 - Not used
gs_lwa_num_lights Integer 11 3D To set the number of generated light sources.
gs_lwa_diversion_angle Angle 5 3D Angle of the sun's light cone
gs_lwa_cast_shadows Boolean 1 3D Shadow casting on / off.
gs_lwa_different_sun_color Boolean 0 3D Different sun color for sunset/sunrise
gs_lwa_sunset_R Integer 193 3D sunset/sunrise red component
gs_lwa_sunset_G Integer 102 3D sunset/sunrise green component
gs_lwa_sunset_B Integer 51 3D sunset/sunrise blue component
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

The Light Cone

Direction vector of the light sources are distributed within a cone's area.
The angle of the cone can be adjusted with a GDL parameter.
sample light set

Different Sunrise/Sunset Color

For sun study generation Sun Object offers different sun color settings when sun altitude is low (in case of sunset or sunrise).
Compare the end frame of the two movies below.

In the following animations you can see the difference between the default setup and the one with modulated sun color (the second one). Click on the pictures below to see the sample movies.

video without sunset coloring video with sunset coloring

3. Usage

Place the Sun Object just anywhere in the plan.

Do not forget to turn off default sun light source in LightWorks® rendering engine's settings dialog. If you made sun study, you have to check on the "Rebuild Model for Each Frame" checkbox.

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

Important settings affecting the effect of the Sun Object

By lamp settings + Sun off

Important settings when Sun Object used in sun studies

Rebuilt model for each frame

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