Technical drawings - Projection methods - Part 4: Central projection (ISO 5456-4:1996)

Technische Zeichnungen - Projektionsmethoden - Teil 4: Zentralprojektion (ISO 5456-4:1998)

Dieser Teil von ISO 5456 legt die Grundregeln für die Entwicklung der Zentralprojektion und deren Anwendung in technischen Zeichnungen fest.

Dessins techniques - Méthodes de projection - Partie 4: Projection centrale (ISO 5456-4:1996)

La présente partie de l'ISO 5456 prescrit des règles de base pour le développement et l'application de la projection centrale dans les dessins techniques.

Tehnične risbe - Metode projekcije - 4. del: Centralna projekcija (ISO 5456-4:1996)

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Published
Publication Date
23-Oct-2001
Withdrawal Date
29-Apr-2002
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6060 - Definitive text made available (DAV) - Publishing
Start Date
24-Oct-2001
Completion Date
24-Oct-2001

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SLOVENSKI STANDARD
01-februar-2002
7HKQLþQHULVEH0HWRGHSURMHNFLMHGHO&HQWUDOQDSURMHNFLMD ,62
Technical drawings - Projection methods - Part 4: Central projection (ISO 5456-4:1996)
Technische Zeichnungen - Projektionsmethoden - Teil 4: Zentralprojektion (ISO 5456-
4:1998)
Dessins techniques - Méthodes de projection - Partie 4: Projection centrale (ISO 5456-
4:1996)
Ta slovenski standard je istoveten z: EN ISO 5456-4:2001
ICS:
01.100.01 7HKQLþQRULVDQMHQDVSORãQR Technical drawings in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 5456-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2001
ICS 01.100.10
English version
Technical drawings - Projection methods - Part 4: Central
projection (ISO 5456-4:1996)
Dessins techniques - Méthodes de projection - Partie 4: Technische Zeichnungen - Projektionsmethoden - Teil 4:
Projection centrale (ISO 5456-4:1996) Zentralprojektion (ISO 5456-4:1998)
This European Standard was approved by CEN on 30 September 2001.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5456-4:2001 E
worldwide for CEN national Members.

CORRECTED 2002-01-02
Foreword
The text of the International Standard from Technical Committee ISO/TC 10 "Technical drawings,
product definition and related documentation" of the International Organization for Standardization
(ISO), the secretariat of which is held by CMC.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2002, and conflicting national standards shall be
withdrawn at the latest by April 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 5456-4:1996 has been approved by CEN as a European
Standard without any modification.
NOTE Normative references to International Standards are listed in annex ZA (normative).
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of -any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated by
(mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 10209-2 1994 Technical product documentation - EN ISO 10209-2 1996
Vocabulary - Part 2: Terms relating to
projection methods
INTERNATIONAL ISO
STANDARD 5456-4
First edition
1996-06-15
Corrected and reprinted
1998-08-01
Technical drawings — Projection
methods —
Part 4:
Central projection
Dessins techniques — Méthodes de projection —
Partie 4: Projection centrale
A
Reference number
ISO 5456-4:1996(E)
ISO 5456-4:1996(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national standards bodies (ISO member bodies). The work of
preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for
which a technical committee has been established has the right to be rep-
resented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 5456-4 was prepared by Technical Committee
ISO/TC 10, Technical drawings, product definition and related documen-
tation, Subcommittee SC 1, Basic conventions.
ISO 5456 consists of the following parts, under the general title Technical
drawings — Projection methods:
— Part 1: Synopsis
— Part 2: Orthographic representations
— Part 3: Axonometric representations
— Part 4: Central projection
Annexes A and B of this part of ISO 5456 are for information only.
©  ISO 1996
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii
©
ISO ISO 5456-4:1996(E)
Introduction
Central projection (perspective) is a realistic pictorial representation ob-
tained by projecting the object to be represented from a point at finite
distance (projection centre) on a single projection plane (normally the
drawing surface). Central projection provides excellent visual appearance
of the object (monocular vision) and is often used in architectural draw-
ings.
iii
©
INTERNATIONAL STANDARD  ISO ISO 5456-4:1996(E)
Technical drawings — Projection methods —
Part 4:
Central projection
3.1  alignment line: Line parallel to a given line
1  Scope
passing through the projection centre. Its intersection
with the projection plane gives the vanishing point of
This part of ISO 5456 specifies basic rules for the
all lines parallel to the given line.
development and application of central projection in
technical drawings.
3.2  height of projection: Vertical distance of the
2  Normative reference
projection centre from the basic plane.
The following standard contains provisions which,
through reference in this text, constitute provisions of
3.3  horizontal distance: Distance between the
this part of ISO 5456. At the time of publication, the
projection centre and the projection plane.
edition indicated was valid. All standards are subject
to revision, and parties to agreements based on this
part of ISO 5456 are encouraged to investigate the
possibility of applying the most recent edition of the
3.4  projection angle: Angle formed by the projec-
standard indicated below. Members of IEC and ISO
tion plane and the horizon plane.
maintain registers of currently valid International
Standards.
3.5  scale point: Vanishing point of the horizontal
ISO 10209-2:1993, Technical product documentation
— Vocabulary — Part 2: Terms relating to projection direction orthogonal to that bisecting the angle formed
by the horizon line and the alignment line of the given
methods.
horizontal line, and allowing the true length of the
projection of the given line to be determined.
3  Definitions
For the purposes of this part of ISO 5456, the defi-
nitions given in ISO 10209-2 and the following defi- 3.6  station of observation: Orthogonal projection
of the projection centre onto the basic plane.
nitions apply.
©
ISO 5456-4:1996(E) ISO
tation (horizontal lines remain horizontal and vertical
4  Symbols
lines remain vertical). All lines perpendicular to the
projection plane converge at the vanishing point, V,
Letter symbols for terms used in central projection
coinciding with the main point, C, (see figure 3 and
are given in table 1 and illustrated in figures 1 and 2,
7.2.1 and 7.3).
as well as in the figures mentioned in table 1.
5.2  Two-point method
Table 1 — Letter symbols
A two-point projection method is a central projection
No. Term Letter symbol Figure
of an object having its vertical outlines and edges
1)
Projection plane T 1 parallel to the projection plane (particular position). All
horizontal lines of a representation converge at multi-
1)
Basic plane G 1
ple vanishing points V , V , V , ., on the horizon line
1 2 3
1)
Basic line X 1 (see figure 4 and 7.2.2 and 7.4).
3.4 Projection angle b 5
1) 5.3  Three-point method
Horizon plane HT 1
1)
Horizon line h 1
A three-point projection method is a central projection
3.1 Alignment line Vl 4 of an object having no outlines or edges parallel to the
projection plane (any position). If the projection plane
1)
Main point C 1
is inclined towards the projection centre, i.e. b > 90°,
1)
Vanishing point V 4
the vanishing point for vertical lines is situated below
the horizon line (see figure 5 and 7.5.1 and 7.5.2).
1)
Main projector pL 1
1)
Projection centre O 1
5.4  Coordinate method
3.2 Height of projection H 1
3.3 Horizontal distance d 1
Representation by the coordinate method is based on
simple proportions.
1)
Vision cone K 2
1)
Circle of vision Ks 3
The coordinates, related to the main projector of all
1)
relevant points of the object to be represented, are
Vision angle a 2
taken by the graphic method from the basic plane and
1)
Projector Pl 3
elevation. From these point coordinates, the image
1)
Distance point DP 13
coordinates are obtained by a calculation method and
entered to scale. The image points are connected to
3.5 Scale point MP 14
each other to provide a clear representation of the
3.6 Station of observation Sp 1
object (see figure 6).
1)  Terms already defined in ISO 10209-2.
6  Principle
5  Central projection methods
6.1  Location and position of the projection
plane
The mode of the central projection depends on the
position of the object to be represented with respect
The image size of an object can be varied by parallel
to the projection plane.
shifting of the projection plane. If the object is placed
in front of the projection plane, the representation will
For possible positions and applicable projection
be enlarged. The object behind the projection plane
methods, see 5.1 to 5.4.
will result in a smaller image. Figure 7 shows the
change in image size depending on the position of the
5.1  One-point method
object with respect to the projection plane.
A one-point projection method is a central projection
Figure 8 shows the change in image size depending
of an object having its principal face parallel to the
on the method of representation with vertical or
projection plane (special position). All parallel outlines
inclined projection planes. b is the included angle
and edges of the object which are parallel to the
between the projection plane and the basic plane near
projection plane retain their direction in this represen- the projection centre.
©
ISO ISO 5456-4:1996(E)
Figure 1 — Projection model of the central projection
©
ISO 5456-4:1996(E) ISO
Figure 2 — Vision cone and vision angle in the projection model of the central projection
©
ISO ISO 5456-4:1996(E)
Figure 3 — Projection model with vertical projection plane and an object in a special position
with respect to the projection plane
Figure 4 — Projection model with vertical projection plane and an object in a particular position
with respect to the projection plane
©
ISO 5456-4:1996(E) ISO
Figure 5 — Projection model with inclined projection plane and an object in any position with respect
to the projection plane (b > 90°)
©
ISO ISO 5456-4:1996(E)
Figure 6 — Projection model with vertical projection plane and an object in special position, showing the
lengths used in the mathematical formula for calculation of the perspective image
b = 90°, b > 90°; b < 90°
1 2
Figure 7 — Location of projection planes Figure 8 — Position of projection planes
©
ISO 5456-4:1996(E) ISO
6.2  Circle of vision and vision cone instructive since length, width and height do not
match the object’s inherent proportions (see figure 9).
To obtain a fully instructive image of an object without
peripheral distortions on the projection plane, the
An object can be depicted nearly undistorted if the
object must be positioned within a vision cone having
projectors result in a bundle of rays inclined not more
an aperture angle not greater than 60°.
th
...

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