Currently I am defining PV on roof using shading:site:detail to input the coordinates of my shading site,which is my entire roof area(4 vertex coordinates), but the problem is I do not know how to add tilt angle for the PV panel.Can I use one of the vertex coordinates I defined in shading:site:detailed as the starting coordinate for Shading:Building?In this case which vertex should I use as my starting coordinate?In addition,what value should I put for length and height under Shading:building?Are the height and length the same as the depth and length of the solar module?