Multiview orthographic projection
The normal projection or three-panel projection is a method for the graphical representation of a spatial object in different planar views.
Use
The drawings of the normal projection often used in architecture and construction. Presentation drawings are mainly of the representation of a concept or design. Floor plans, sections and elevations, however, are measurable drawings. These " drawings " are the planners to define the dimensions of a structure exactly. The performers can realize the building based on these drawings.
Even with technical drawings, for example, in engineering drawings of the normal projection are the main form of representation and is essential for the planning and execution.
Views
There are about three orthogonal projection two sides and consequently six views. In the arrangement of views on the paper, there are two systems:
- Projection method 1, and European representation or First Angle Projection named and labeled with FR ( for French, see also chart on the right ) and
The adjacent symbolism allows the basis of a truncated cone and the trapeze as a front view of the identification of the selected method. The unfolding of the projection cube illustrates the logic underlying each.
Three of the projections serve as the main view for the three-panel projection. When selecting the front view of the most significant side has the advantage. At confusing objects, additional views can be added. Sometimes it is possible to dispense with one of the three views, and one obtains a two- panel projection.
- Projection Method 1
Projection back to the cuboid
Development of backward
The six views
- Projection Method 3
Projection to the front of the cuboid
Development forward
The six views
Explanation
Geometrically, each point of the object is initially in a spatial coordinate system as P (x | z | y) described. Then each one of the coordinates to a fixed value (e.g., zero ) is set to allow a flat view. This corresponds to a projection in each one of the fundamental levels.
A building (pictured below left) to be displayed in three-panel projection. Its vertices are projected onto the ground plane and reconnected ( bottom center ). Hidden edges are thereby broken lines.
Three projections are now drawn on a plane, by cutting open along the x- axis of the spatial arrangement of the three layers and folding down in the yz plane. The x-axis in the drawing occurs then twice.
Projection of the views in the 3D drawing
Excellent lines and planes
A principal straight line is a straight line which is parallel to one of the image planes. Main lines are in the corresponding image plane always undistorted, so you can read their spatial length directly in the image plane. A projected line is a straight line parallel to the projection direction. Projecting lines are shown in the corresponding image plane as a point, their length so can not be reconstructed from its image.
A principal plane is a plane that is parallel to an image plane. Principal planes are always undistorted in the corresponding image plane. A projecting plane is a plane which is parallel to the projection direction. Projecting levels are shown in the corresponding image plane as a straight line.
Depending on whether it is at the image plane to the ground plan, which is elevation or cross crack plane, it is called first, second and third principal lines or planes, or by first-, second-and drittprojizierenden straight lines or planes.