First angle projection is a method of orthography projection. It assumes the object being viewed is in the first quadrant of a three-dimensional coordinate system, the plane of projection is behind the object and is assumed to be non-transparent, and the observer is in the bottom left in the composite.
Continue ReadingFirst angle projection is the most common method of orthographic projection, representing a three-dimensional object in two dimensions by projecting a cross-sectional view from one of up to six viewpoints parallel to one of the faces of the object.
The United States is the only country that uses third angle projection, which assumes the opposite of first angle; the object is in the third quadrant, the plane of projection is in front of the object and is assumed to be transparent, and the observer is in the top right in the composite view.
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