Color Defines the light color. Intensity Species the light intensity. Exposure This is an additional control over the standard light intensity. Exposure is in many cases a preferred control due to its likeness to photography. Final light intensity is thus computed by: Light Spread Specifies the spread of the light. A spread of 1 is to natural "cosine" spread. Lower spreads will produce a more focused light. From left to right: 0.2, 0.5 and 1.0 (default). Decay Rate Specify the rate at which the light intensity decreases in function of the distance to the light source. The available values are: Normalize Intensity by Area This will devide the total intensity of the area light by its area. The net effect of this is that no matter the scale of your area light, the intensity will remain the same. This non-physical behaviour can be handy when adjusting shadows from area light: shadow softness adjustments (area light size) will not change the overall intensity. From left to right: off (default) and on. Color Defines the light color. Intensity Species the light intensity. Exposure This is an additional control over the standard light intensity. Exposure is in many cases a preferred control due to its likeness to photography. Final light intensity is thus computed by: Light Spread Specifies the spread of the light. A spread of 1 is to natural "cosine" spread. Lower spreads will produce a more focused light. From left to right: 0.2, 0.5 and 1.0 (default). Decay Rate Specify the rate at which the light intensity decreases in function of the distance to the light source. The available values are: Normalize Intensity by Area This will devide the total intensity of the area light by its area. The net effect of this is that no matter the scale of your area light, the intensity will remain the same. This non-physical behaviour can be handy when adjusting shadows from area light: shadow softness adjustments (area light size) will not change the overall intensity. From left to right: off (default) and on.I = intensity * pow(2, exposure)
Parameter Description No Decay Light intensity remains constant with respect to distance. Linear Light intensity decreases linearly with distance. Quadratic Light intensity decreases proportionally to the square of the distance. This is the physically correct behaviour. Cubic Light intensity decreases proportionally to the cube of the distance. I = intensity * pow(2, exposure)
Parameter Description No Decay Light intensity remains constant with respect to distance. Linear Light intensity decreases linearly with distance. Quadratic Light intensity decreases proportionally to the square of the distance. This is the physically correct behaviour. Cubic Light intensity decreases proportionally to the cube of the distance.