Sun View Factor

It has been very quite - not many requests. So in the meantime, I worked on another otl for evaluation. I have created a node called "Sun View factor". It is similar to the Sky View Factor node:

• For the Sky View Facto, it calculates the % of the sky dome that is visible from the centre of any face.
• For the Sun View Factor, it calculates the % of the sun dome that is visible from the centre of any face.

The sun dome is the area of sky where the sun may be at some point in the year. It is a slice of the sky dome. So , if you get a Sun View Factor of 100%, it means that the sun is always visible, 100% of the year.

The other thing I have added to the node, is the option to apply Lambert's cosine law. This will give a result that is more closely related to the amount of solar radiation hitting the face. Basically, when this law is applied, the calculation takes into account the fact that the sun hitting a face straight on is more intense than the sun is hitting a face obliquely. If you apply the Cosine Law, then the values you get will always be lower than without the law - often about half. So you will never get 100% - even for you roof.

Here is the node:

• http://files.patrick.janssen.name/2010/sun_view_factor.zip

If you right click on the node, and select Help, you will find some help for inputs and parameters.