Vector projections

http://www.mining-enc.ru/images/vektornye_proekcii_resize.jpg
The depiction of the mine workings as the vector projections. Underground mine, Horizon, Scale.

VECTOR PROJECTIONS (EN: vector projections; DE: Vektorprojektionen; FR: projections vectorielles; ES: proyecciones vectoriales; RU: векторные проекции) is the depiction of the object (for example, of the mine workings) on the plane with the help of the parallel vectors, the magnitude of which is proportional to their distance from the points of the object to the plane of projection (the zero horizon). The direction of the vectors, and the scale of the construction, are selected while taking into account the achievement of the best perception of the image. The start of the each vector (of positive vector, and of negative vector) is located within the place of the orthogonal projection of the point. They use the vector projections for the compilation of the special three-dimensional plans of the mine workings (see the Figure), and of the geological structures, when it is required to preserve the good measurability along the determined directions. The source data for the vector depiction of the mine workings, and of the geological structures, are the horizontal and vertical sections throughout the deposit (throughout the underground mine). They perform the construction of the vector projections using the graphical method, using the copying of the sections onto the sheet of paper without the distortion, while shifting them one relatively to another along the selected direction proportionally to the distance between them.