Glossary

Bidirectional reflectance distribution function

Bidirectional reflectance distribution function or BRDF is a 7D model containing geometry, textures and reflectance of the subject. The seven dimensions of the BRDF are as follows: 3 cartesian X,Y,Z and 2 for the entry angle and 2 for the exit angle of the light.

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Covert modeling

Covert modeling refers to both covertly modeling aspects of a subject i.e. without express consent.

Main known cases are

• Covertly modeling the human appearance into 7-dimensional [[#Bidirectional reflectance distribution function|]] model or other type of model.
• Covertly modeling the human voice

There is work ongoing to model e.g. human's style of writing, but this is probably not as drastic a threat as the covert modeling of appearance and of voice.