# 3D to 2D Orthographic Projection Delineation Techniques

## Presentation on theme: "3D to 2D Orthographic Projection Delineation Techniques"— Presentation transcript:

3D to 2D Orthographic Projection Delineation Techniques
Clipping Plane Methodology

Graphical Representation
The vast majority is 2D representation of 3D objects Technical Documentation – Construction Documents, basic communication with peers 3D conception –> 2D representation –> 3D realization Computer Models can be “photographed” – images and line drawings can be generated much faster than can be drawn Extraction Methodology – design in 3D, extract 2D

Orthographic Projection
A means of representing a three-dimensional (3D) object in two dimensions (2D) A perspective projection with a hypothetical viewpoint—e.g., one where the camera lies an infinite distance away from the object and has an infinite focal length, or "zoom". (parallel projection) Multi-view Orthographic Projection Axonometric Orthographic Projection Non-Orthographic (Perspective) Orthographic

Multi-View Orthographic
Each projection plane is parallel to one of the coordinate axes of the object resulting in visual distortion / abstraction

Architectural Plan Also called plan view. a drawing made to scale to represent the top view or a horizontal section of a structure

Architectural Section
A representation of an object as it would appear if cut by a plane, showing its internal structure.

Architectural Elevation
A drawing or design that represents an object or structure as being projected geometrically on a vertical plane parallel to one of its sides.

Axonometric Axonometric
A skewed Orthographic Projection so that multiple sides are visible at once a three-dimensional object is represented by a drawing having all axes drawn to exact scale, resulting in the optical distortion of diagonals and curves Trimetric – arbitrary foreshortening Isometric

Isometric a three-dimensional object is represented by a drawing having the horizontal edges of the object drawn usually at a 30° angle and all verticals projected perpendicularly from a horizontal base, all lines being drawn to scale

Clipping Planes Uses Orthographic Cameras – Relatively Universal
Extracts from solids or surfaces alike Uses two planes perpendicular to the focal length of the camera – Near Clipping Plane and Far Clipping Plane Only displays graphical information between the near clip and the far clipping plane

Clipping Planes

Plotting to File with Clipping Planes
The clipping plane method can be used in conjunction with the plot to file method. Plotting to file allows three important options in a single method – Allows rendering – allows the use of hidden line projection to “hide” lines that should be obscured with planes in 3D space. Flattens the drawing – gets rid of the Z dimension and flattens the 3D model to a 2D vector drawing Separates the line drawings – Drawings can be edited in respect to themselves without adversely altering the model

Plotting to File with Clipping Planes – AutoCAD Method
Import the 3D model Page Setup Manager for a real-scale vector file Set up the layout for the desired view View Scale Use clipping planes to “cut” Use hidden line rendering on the viewport Plot to file Import plotted file into a [new] drawing Make it pretty Poche Entourage Line weight

Plotting to File with Clipping Planes
3 datasets to manage Original model file Multiple layouts preferably – one for each “view” Vector files (DXB) Individual plot files with extensions that are not .dwg. These are not opened, but imported The Presentation file All vector files are imported here for cleanup and delineation