honeybee_plus.radiance.geometry.instance module

Radiance Transfunc Instance.

http://radsite.lbl.gov/radiance/refer/ray.html#Instance

class honeybee_plus.radiance.geometry.instance.Instance(name, modifier=None, values=None, is_opaque=None)

Bases: honeybee_plus.radiance.geometry.geometrybase.RadianceGeometry

Radiance Instance.

An instance is a compound surface, given by the contents of an octree file (created by oconv).

mod instance id 1+ octree transform 0 0

If the modifier is “void”, then surfaces will use the modifiers given in the original description. Otherwise, the modifier specified is used in their place. The transform moves the octree to the desired location in the scene. Multiple instances using the same octree take little extra memory, hence very complex descriptions can be rendered using this primitive.

There are a number of important limitations to be aware of when using instances. First, the scene description used to generate the octree must stand on its own, without referring to modifiers in the parent description. This is necessary for oconv to create the octree. Second, light sources in the octree will not be incorporated correctly in the calculation, and they are not recommended. Finally, there is no advantage (other than convenience) to using a single instance of an octree, or an octree containing only a few surfaces. An xform command on the subordinate description is prefered in such cases.