Shading objects

What it is

Obstacles near the devices that cast shadows on them: buildings, rooftop units, parapets, fences, trees and tanks. Objects shade the devices in every shading model, with row-to-row shading on or off. Lengths are in the scene's unit, the same for every length.

Typical values and how to get it

Model what casts shadows onto the modules; distant objects belong in the horizon profile. Use a prism for a building or a rooftop unit, a wall for a parapet or a fence, a tree line for a hedge or a deciduous tree, and a cylinder for a tank, a pole or an evergreen tree. Every vertex is [x, y, z, h]: a base point at elevation z and the object's height h above it, so base and top may both slope; z shares the datum of the placements. Up to 2,000 objects; ids are unique across placements, objects and outlines.

With row-to-row shading on and the shading-factor table or the direct projection chosen on the Model tab, each object's silhouette is projected along the sun onto every device plane together with the neighbouring devices, and it enters the sky and ground shading through the same geometry. With any other row model, or with row-to-row shading off, each device sees the objects as a mask from its centre: for every compass degree, the range of sun heights at which an object hides the sun. The mask acts on the direct beam and the circumsolar light that the rows left lit, so the rows and the objects never remove the same light twice. Solids block the direct sunlight completely and a tree line lets a seasonal fraction through; where objects overlap, the lowest transmittance applies. If not given: none: the scene has no shading objects.

References

1. Heisler 1986, Effects of individual trees on the solar radiation climate of small buildings, Urban Ecology 9(3–4) 337–359

API

scene.objects