QUESTION:

I think I have a problem with the solar exposure function in my ECOTECT model. Any object selected has 100% shading all day. This doesn't seem right.

Is there something I am doing wrong ?

ANSWER:

Firstly, you will need to check the version number you have of ECOTECT. There was a slight bug with this function that may have caused this issue in v5.20 and I think v5.20(a) of ECOTECT.

If you have v5.20(b) you should be okay.

If your version is alright, then it is most likely either of the following;

• haven't done an inter-zonal adjacency calculation for your model
• the surfaces that you select are not pointing "outwards"

It is very important that an inter-zonal adjacency calc is done in your model so that ECOTECT can work out the shading masks for each object. Without this it has no idea about the effects of external geometry etc.

If you attempt a Solar Exposure calc. without doing this, ECOTECT should warn you of the potential error.

For the "inwards" vs. "outwards" issue, you may like to look at the following related FAQ: "which side is considered the internal or external".

However, to summarise briefly here, the surface normal for an object must be pointing in the direction that you consider outside. If it is pointing towards the inside/middle of a zone then it will most likely be shaded all the time, i.e. 100% shading.