DGP is an indication of the percentage of people who would be disturbed by glare (Wienold and Christoffersen, 2006). It will be generated as a hemispherical fisheye image, using the eye and focus positions set in the Sky/Eye tab. For more information go to Section 4: Sky/Eye tab In this image, the glare sources will be displayed in yellow together with the DGP value. The value will be classified as one of the following four categories:
Imperceptible: less than 35%
Perceptible: 35% - 40%
Disturbing: 40% - 45%
Intolerable: greater than 45%
The DGP value or percentage of people disturbed in the example image below is 39.70%.
The sky file used for the source image is noted in the image in the following format:
Day_Time_Sky Type
For the example image: Sep 21 is the day, 14:00 is the time and Sunny Sky is the sky type. Please refer to Section 4: Sky/Eye Tab for more information on sky types used in RadianceIES.
If the Show Summary box is checked, a summary window will pop-up when you click on Simulate:
When you click Yes, the simulation will run. When a Daylight Glare Probability image is created, two images will be created, the parent image and the DGP image. The parent image is the hemispherical fisheye image. The DGP image has the label _dgp added to the file name, e.g. image1.pic would generate image1_dgp.pic
You can delete the DGP glare files as you would for any other image file (it will give you the prompt to ensure that this was intended). However, if you try to delete the parent luminance image and a glare image exists, you will get an additional prompt:
In effect you cannot delete the parent image without also deleting the generated glare image. Also, if you rename a parent image then the glare image is also renamed.
It is also possible to create the required hemispherical fish-eye image by using the options on the Sky/Eye tab and the Standard Image option (see Section 4: Skye/Eye Tab), but the DGP image will have to be manually generated afterwards. To do this, open the hemispherical fisheye image and select the Glare > Daylight Glare Probability menu option. Similarly, the DGP image will have the label _dgp added to the file name, e.g. image1.pic would generate image1_dgp.pic.
