Unfortunately, the description of function for the Lights tab of the object editor is splitted and exists at two positions in the DELTAGEN HUB user guide for 3DEXCITE DELTAGEN MARKETING SUITE R2018x.
As simplification for an easier understanding, use this article as an addendum to the chapter Object Editor in the user guide to get an overview of the entire description of function for the Lights tab.
In case one of the four available light types (headlight, directional light, spot light or point light) is selected in the scene tree, the Lights tab of the object editor displays several settings to modify the light source as desired.
Overview of the four light types
The light type Headlight exists by default in each scene and has a fixed position at the top of the scene tree right above the model. Due to this positioning, the entire model is lit by the headlight. Or in case the the headlight has been switched of, the entire model appears black. The other three light types lit only specific objects of the model, depending on the selected group for which the light was created. To create a directional light, spot light or point light, click Scene > Create light and select the desired light type. To disable a created light, either clear the corresponding visibility check mark in the scene tree or clear the check mark at the top left corner of the Lights tab in the object editor.
For all four light types it is possible to the specify the light intensity as well as the light color:
There are two possibilites to specify the desired light color:
- choose one of the available color spaces (HSV, RGB and Lab) and set the associated values accordingly;
- click the color circle icon and move the two existing markers the to the correct positions for the desired color;
Furthermore, exists the possibility to select a predefined standardized light source. Open the dropdown list for Normed light and choose between: Blackbody, Morning, Day, D50, D55, D65 or D75
Intensity specifies the light intensity. To regulate the intensity change the value either by using the small arrow buttons in the user interface or by using the + and – keys on the numbers keypad. For spot light and point light exist further Illumination settings. Spot light has two more settings: Cut off angle to specify the cut off angle of the light cone and Penumbra angle to specifiy the softness of the light cone at the outer edge. For point lights it is possible to insert a light profile for Goniometric lights. This light profile consists of settings such as light temperature, light direction and illumination factor.
For the three createable light types the following five visibility attributes are displayed in the Lights tab:
- Visible in reflection
- Visible in refraction
- Visible in transmission
- Casts direct shadows
- Casts caustics
By default, all five visibility attributes are enabled. Expect the two attributes “Visible in reflection” and “Casts caustics” it is possible to disable the visibility attributes as desired.
Direction specifies the axis of direction in which the light shines. Either enter the coordinates of the axis or click the camera icon to use the axis of direction from the camera as light direction.
Position specifies the position of the light. Either enter the coordinates or click the camera icon to use the position of the camera as light position.
Spot light and point light have the setting Position and spot light and directional light have the setting Direction. For directional lights it is possible to specify the light direction as the current position of the sun in accordance to the place, date and time. Place specifies a place on Earth illuminated by the sun. Either specify the place by setting its latitude and longitude value or use the dropdown list which offers several cities from all over the world. Select the desired city from where the current position of the sun should be taken. Date & time specifies the precise date (day/month), the precise time (hours/minutes) as well as the time zone. These data are used to compute the exact direction from which sunlight shines on the scene.