Attenuation Tab (New Light Dialog Box) - Intergraph Smart Review - Help

Intergraph Smart Review Help

Language
English
Product
Intergraph Smart Review
Search by Category
Help
SmartPlant Foundation / SDx Version
10
Smart Review Version
2020 (15.0)

Provides options for defining various attenuation settings for point and spot lights.

There is no attenuation for distant lighting; therefore, this tab is not provided for the Distant light source command.

None

Specifies that there is no reduction in the intensity of the light based on the distance from the source of the light. This option is selected by default.

MicroStation

Specifies that the light attenuation effects be styled after those found in MicroStation. This option is the default setting for MicroStation lights that are attenuated. If the MicroStation light is not attenuated, the None option is selected.

Fast

Specifies that the light attenuation effects be styled after ModelView's fast attenuation. When this option is selected, the light becomes dimmer more quickly.

Slow

Specifies that the light attenuation effects be styled after ModelView's slow attenuation. When this option is selected, the light becomes dimmer more slowly.

Custom

Specifies an exact attenuation effect based on the three constants in the following fall-off (F) equation: F = 1.0 / (c1 + (c2*distance-to-light) + (c3*distance-to-light- squared).

Constant component from 0 to 10

Specifies a value for the constant attenuation component. The default value is 1.0

Linear component from 0 to 1

Specifies a value for the linear attenuation component. The default value is 1.0.

Quadratic component from 0 to 1

Specifies a value for the quadratic attenuation component. The default is value is 1.0

  • Attenuation simulates the fall off of light from a positional light source. Constant fall off is the slowest and quadratic fall of is the fastest with linear in between constant and quadratic.

  • OpenGL attenuates positional lights (points and spots) by an attenuation factor composed of the constants listed previously using the following equation: Attenuation factor = 1 / (C+L*d+Q*d*d)

  • Ambient, diffuse, and specular are all attenuated; global ambient and emission are not attenuated.

  • For MicroStation lights, this tab is disabled, and the MicroStation option is selected if the light is attenuated.

  • When the Custom option is selected, the light can be specified to exact catalog standards. For example, this option would be used to specify a GE 30 watt frosted bulb.

  • Using non-default attenuation does require extra calculations and may slow performance.

See Also

New Light Dialog Box
Place a New Spot Light