Oblique Projections, ContinuedSelecting aOnly one surface of the object can be parallel to the picture plane andsurfacerepresented in its true size and shape.Place the surface with the irregularoutline or contour (curved or circular features) parallel to the picture plane orplace the longest dimension of the object parallel to the picture plane. If theobject is such that the surface with the longest dimension conflicts with theirregular surface, always place the irregular surface parallel to the pictureplane.This procedure minimizes distortion in the projected image.Direction of theLine lengths projected in oblique projection are determined by the angle ofprojectors andthe projectors to the plane of projection. Projectors that angle 45° to theline lengthplane of projection project lines perpendicular to the plane of projection intrue length. When the angle of the projectors is greater, the line projected isshorter. When the angle of the projectors is smaller, the projected line islonger. Theoretically, any line perpendicular to the plane of projection couldproject any length from zero to infinity. Any line parallel ‘to the plane ofprojection will project in true size.Figure 6-3 shows line length relative to the angle of the projectors.Figure 6-3.—Line length: A. Lines parallel, and B.Lines perpendicular to the plane of projection.Continued on next page6-5

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