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Shading Mask #

Introduction#

The shading mask analysis is used to create shading masks which can be used in other analyses like radiation or daylight. A shading mask describes the relationship, within a scene, between an analysis point and a hemisphere using shading factors. A shading factor is a multiplier for how much the radiative energy from a specific cell in the hemisphere will impact the analysis point.

A single shading mask where each cell has been coloured by the amount of impact it has on the analysis point.

Info

There are three factors that primarily affect the shading factor:

  • The incident angle from the hemisphere cell in relation to the analysis point normal, a cell directly above the analysis point renders a higher impact than one at an oblique angle.
  • The amount of unobstructed visibility between the analysis point and the cell, a cell that is fully visible from the analysis point has a higher impact than one that is obstructed.
  • The transparency and reflective properties of the materials in the scene, bright and highly reflective materials increases the impact by reflecting light throughout the scene.

Set Up#

The analysis can run either using a temporary scene or a static scene where geometry has been added prior to running the analysis.

Geometry Group#

The shading mask analysis requires at least one geometry group in order to run. It either has to be supplied through the scene objects parameter, if the analysis is running on a temporary scene, or added to a static scene prior to running the analysis.

A sample scene for creating a shading mask with an analysis point and a set of geometries.

Analysis Points#

The analysis points specify both the location and the orientation of where the shading masks should be evaluated. An analysis point is usually created on a surface using the normal of the surface as the analysis point direction.

Hemisphere#

The hemisphere specify the amount of cells and their layout over the sky dome. More cells will require more samples in the analysis to create accurate results.

Sampling Settings#

The sampling settings specify the amount of samples that should be traced for each analysis point and the maximum amount of bounces that should be considered. It affects the quality of the analysis as well as the time is takes to run.

Visibility Mask#

The visibility mask can be used to exclude geometry groups from the analysis. This can be useful when the same scene is used for multiple analyses that require different geometric compositions.

Results#

The analysis will output a shading mask for each analysis point. In the shading mask there is one shading factor for each cell in the input hemisphere, specifying the impact that each cell has on the analysis point.

A shading mask coloured by the impact each cell has on the analysis point from low impact black to high impact white.