Sun Object

General Description
Parameters
- The Light Cone
- Different Sunrise/Sunset Color
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.

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