Sky View Factor calculation: different possible approaches

The Ladybug_Shading Mask component allows to define the Sky View Factor starting from a 3D model.

The Rayman software or other sw allow to do the same starting from a real image captured with a fish-eye.

I have seen if in ladybug there is a specific component but I have not found it. So I ask: “have you considered to implement this features in ladybug?”




Are you looking for a component that takes a fisheye image as an input or a workflow to create the whole process in Grasshopper? Grasshopper’s Image sampler does take an image and returns the colors for each pixel. You can use Honeybee to render a fish-eye view looking to the sky and then count the number of sky pixels. Apply a black material to all the geometries, generate a uniform sky and set -ab to 0 and pick a high value for -ar.


Here is an example.

Dear Mostapha,

I have used a basic image (Image_for_comparison.bmp, attached below) to compare the SVF calculated with Rayman and that calculated using the above simple script (I have modified it by adding “1-” in the formula).

As you can see from the two images below, the result are a bit different and I’m not able to found an explanation.

Can you try to explain me why it happens?

Image_for_comparison.bmp (678 KB)

I have also used the image attached below but the difference in the two values determined by the two softwares persists. I think is due to the different geometry of the input image: square vs circular

How can I exclude the 4 corners in the native grasshopper image sampler component?


I have tried a new code:

Important: in input you have to consider a .png file with transparent background

Hi,mostapha, the picture cannot be viewed. Could you please tell me how to use Honeybee to render a fish-eye view looking to the sky and then count the number of sky pixels?