BS ISO 5456-4-2001 Technical drawings - Projection methods - Central projection《技术制图 投影法 中央投影法》.pdf

1、BRITISH STANDARD BS ISO 5456-4:1996 Technical drawings Projection methods Part 4: Central projection ICS 01.100.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 5456-4:1996 This British Standard, having been prepared under the direction of the Consumer Products and Ser

2、vices Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 September 2001 BSI 07-2001 ISBN 0 580 38242 7 National foreword This British Standard reproduces verbatim ISO 5456-4:1996 and implements it as the UK national standard. The UK participati

3、on in its preparation was entrusted by Technical Committee TDW/4, Engineering drawing, metrology, precision measurement and all related documents, to Subcommittee TDW/4/-/1, General drawing principles, conventions and related documents, which has the responsibility to: A list of organizations repres

4、ented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Corresponden

5、ce Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of it

6、self confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and

7、 promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 33 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments iss

8、ued since publication Amd. No. Date CommentsA Referencenumbe r ISO54564:1996 (E) INTERNATIONAL STANDARD ISO 54564 Firstedition 19960615 Correctedandreprinted 19980801 TechnicaldrawingsProjection methods Part4: Centralprojection DessinstechniquesMthodesdeprojection Partie4:ProjectioncentraleISO54564:

9、1996(E) ii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwide federationofnationalstandardsbodies(ISOmemberbodies).Theworkof preparingInternationalStandardsisnormallycarriedoutthroughISO technicalcommittees.Eachmemberbodyinterestedinasubjectfor whichatechnicalcommitteehasbeenes

10、tablishedhastherighttoberep resentedonthatcommittee.Internationalorganizations,governmentaland nongovernmental,inliaisonwithISO,alsotakepartinthework.ISO collaboratescloselywiththeInternationalElectrotechnicalCommission (IEC)onallmattersofelectrotechnicalstandardization. DraftInternationalStandardsa

11、doptedbythetechnicalcommitteesare circulatedtothememberbodiesforvoting.PublicationasanInternational Standardrequiresapprovalbyatleast75%ofthememberbodiescasting avote. InternationalStandardISO54564waspreparedbyTechnicalCommittee ISO/TC10,Technicaldrawings,productdefinitionandrelateddocumen tation,Su

12、bcommitteeSC1, Basicconventions . ISO5456consistsofthefollowingparts,underthegeneraltitle Technical drawingsProjectionmethods : Part1:Synopsis Part2:Orthographicrepresentations Part3:Axonometricrepresentations Part4:Centralprojection AnnexesAandBofthispartofISO5456areforinformationonly.OSI ISO54564:

13、1996(E) iii Introduction Centralprojection(perspective)isarealisticpictorialrepresentationob tainedbyprojectingtheobjecttoberepresentedfromapointatfinite distance(projectioncentre)onasingleprojectionplane(normallythe drawingsurface).Centralprojectionprovidesexcellentvisualappearance oftheobject(mono

14、cularvision)andisoftenusedinarchitecturaldraw ings.INTERNATIONALSTANDARD OSI ISO54564:1996(E) 1 TechnicaldrawingsProjectionmethods Part4: Centralprojection 1Scope ThispartofISO5456specifiesbasicrulesforthe developmentandapplicationofcentralprojectionin technicaldrawings. 2Normativereference Thefollo

15、wingstandardcontainsprovisionswhich, throughreferenceinthistext,constituteprovisionsof thispartofISO5456.Atthetimeofpublication,the editionindicatedwasvalid.Allstandardsaresubject torevision,andpartiestoagreementsbasedonthis partofISO5456areencouragedtoinvestigatethe possibilityofapplyingthemostrece

16、nteditionofthe standardindicatedbelow.MembersofIECandISO maintainregistersofcurrentlyvalidInternational Standards. ISO102092:1993, Technicalproductdocumentation VocabularyPart2:Termsrelatingtoprojection methods. 3Definitions ForthepurposesofthispartofISO5456,thedefi nitionsgiveninISO102092andthefoll

17、owingdefi nitionsapply. 3.1 alignmentline:Lineparalleltoagivenline passingthroughtheprojectioncentre.Itsintersection withtheprojectionplanegivesthevanishingpointof alllinesparalleltothegivenline. 3.2 heightofprojection:Verticaldistanceofthe projectioncentrefromthebasicplane. 3.3 horizontaldistance:D

18、istancebetweenthe projectioncentreandtheprojectionplane. 3.4 projectionangle:Angleformedbytheprojec tionplaneandthehorizonplane. 3.5 scalepoint:Vanishingpointofthehorizontal directionorthogonaltothatbisectingtheangleformed bythehorizonlineandthealignmentlineofthegiven horizontalline,andallowingthetr

19、uelengthofthe projectionofthegivenlinetobedetermined. 3.6 stationofobservation:Orthogonalprojection oftheprojectioncentreontothebasicplane.ISO54564:1996(E) ISO 2 4Symbols Lettersymbolsfortermsusedincentralprojection aregivenintable1andillustratedinfigures1and2, aswellasinthefiguresmentionedintable1.

20、 Table1Lettersymbols No. Term Lettersymbol Figure 1) 1) 1) 3.4 1) 1) 3.1 1) 1) 1) 1) 3.2 3.3 1) 1) 1) 1) 1) 3.5 3.6 Projectionplane Basicplane Basicline Projectionangle Horizonplane Horizonline Alignmentline Mainpoint Vanishingpoint Mainprojector Projectioncentre Heightofprojection Horizontaldistanc

21、e Visioncone Circleofvision Visionangle Projector Distancepoint Scalepoint Stationofobservation T G X b HT h Vl C V pL O H d K Ks a Pl DP MP Sp 1 1 1 5 1 1 4 1 4 1 1 1 1 2 3 2 3 13 14 1 1)TermsalreadydefinedinISO102092. 5Centralprojectionmethods Themodeofthecentralprojectiondependsonthe positionofth

22、eobjecttoberepresentedwithrespect totheprojectionplane. Forpossiblepositionsandapplicableprojection methods,see5.1to5.4. 5.1Onepointmethod Aonepointprojectionmethodisacentralprojection ofanobjecthavingitsprincipalfaceparalleltothe projectionplane(specialposition).Allparalleloutlines andedgesoftheobj

23、ectwhichareparalleltothe projectionplaneretaintheirdirectioninthisrepresen tation(horizontallinesremainhorizontalandvertical linesremainvertical).Alllinesperpendiculartothe projectionplaneconvergeatthevanishingpoint,V, coincidingwiththemainpoint,C,(seefigure3and 7.2.1and7.3). 5.2Twopointmethod Atwop

24、ointprojectionmethodisacentralprojection ofanobjecthavingitsverticaloutlinesandedges paralleltotheprojectionplane(particularposition).All horizontallinesofarepresentationconvergeatmulti plevanishingpointsV 1 ,V 2 ,V 3 ,.,onthehorizonline (seefigure4and7.2.2and7.4). 5.3Threepointmethod Athreepointpro

25、jectionmethodisacentralprojection ofanobjecthavingnooutlinesoredgesparalleltothe projectionplane(anyposition).Iftheprojectionplane isinclinedtowardstheprojectioncentre,i.e. b90, thevanishingpointforverticallinesissituatedbelow thehorizonline(seefigure5and7.5.1and7.5.2). 5.4Coordinatemethod Represent

26、ationbythecoordinatemethodisbasedon simpleproportions. Thecoordinates,relatedtothemainprojectorofall relevantpointsoftheobjecttoberepresented,are takenbythegraphicmethodfromthebasicplaneand elevation.Fromthesepointcoordinates,theimage coordinatesareobtainedbyacalculationmethodand enteredtoscale.Thei

27、magepointsareconnectedto eachothertoprovideaclearrepresentationofthe object(seefigure6). 6Principle 6.1Locationandpositionoftheprojection plane Theimagesizeofanobjectcanbevariedbyparallel shiftingoftheprojectionplane.Iftheobjectisplaced infrontoftheprojectionplane,therepresentationwill beenlarged.Th

28、eobjectbehindtheprojectionplane willresultinasmallerimage.Figure 7showsthe changeinimagesizedependingonthepositionofthe objectwithrespecttotheprojectionplane. Figure8showsthechangeinimagesizedepending onthemethodofrepresentationwithverticalor inclinedprojectionplanes. bistheincludedangle betweenthep

29、rojectionplaneandthebasicplanenear theprojectioncentre.OSI ISO54564:1996(E) 3 Figure1ProjectionmodelofthecentralprojectionISO54564:1996(E) ISO 4 Figure2VisionconeandvisionangleintheprojectionmodelofthecentralprojectionOSI ISO54564:1996(E) 5 Figure3Projectionmodelwithverticalprojectionplaneandanobjec

30、tinaspecialposition withrespecttotheprojectionplane Figure4Projectionmodelwithverticalprojectionplaneandanobjectinaparticularposition withrespecttotheprojectionplaneISO54564:1996(E) OSI 6 Figure5Projectionmodelwithinclinedprojectionplaneandanobjectinanypositionwithrespect totheprojectionplane (b 90)

31、OSI ISO54564:1996(E) 7 Figure6Projectionmodelwithverticalprojectionplaneandanobjectinspecialposition,showingthe lengthsusedinthemathematicalformulaforcalculationoftheperspectiveimage Figure7Locationofprojectionplanes b=90, b 1 90; b 2 90 Figure8PositionofprojectionplanesISO54564:1996(E) OSI 8 6.2Cir

32、cleofvisionandvisioncone Toobtainafullyinstructiveimageofanobjectwithout peripheraldistortionsontheprojectionplane,the objectmustbepositionedwithinavisionconehaving anapertureanglenotgreaterthan60. Heavyperipheraldistortionsoccuronimagesoutside thecircleofvision;theimagedoesnotappearfully instructiv

33、esincelength,widthandheightdonot matchtheobjectsinherentproportions(seefigure9). Anobjectcanbedepictednearlyundistortedifthe projectorsresultinabundleofraysinclinednotmore than30withrespecttothemainprojector.Atthis apertureanglethevisionconeprovidesonlyasmall distortionontheprojectionplane. Figure9O

34、bject,framedinacube,withinandoutsidethecircleofvisionOSI ISO54564:1996(E) 9 Themainprojectorshouldhittheobjecttobede pictedinapartwhichisvisuallyimportant,sothatthe objectiscontainedwithintheminimumvisioncone. 6.3Distance Differentrelativedistancesinfluencetheimagesizeand itsappearance.Whenthedistan

35、cebetweentheobject andtheprojectionplaneisfixedandtheprojectioncentre andtheobjectlieonoppositesidesoftheprojection plane,increasingthedistance( d)betweentheprojection centreandtheprojectionplanegivesenlargedand flattenedrepresentations.Whenthedistance( d)isfixed andtheobjectandtheprojectioncentreli

36、eonopposite sidesoftheprojectionplane,increasingthedistance betweentheobjectandtheprojectionplanegivesre ducedandflattenedrepresentations. 7Principlesandmethodsofdepiction 7.1Piercingmethod Usingthepiercingmethod,thepiercingpointsof projectorswiththeprojectionplaneareshownby basicplaneandelevation,a

37、ndmaybedetermined eitherbydrawingorbycalculation(seefigure10). Thepiercingmethodallowsevencomplexobjects (roundshapes,helicoids,etc.)tobeeasilyrepre sentedincentralprojection. Figure10ProjectionmodelturnedintothedrawingsurfacewithsideviewISO54564:1996(E) OSI 10 7.2Tracepointvanishingpointmethods Wit

38、hthetracepointvanishingpointmethods,the outlinesandedgesoftheobjecttobedepictedare imagedfrombasicplaneandelevation. 7.2.1TracepointvanishingpointmethodA (specialpositionoftheobject) InmethodA,oneverticalfaceoftheobjectisparallel totheverticalprojectionplane(specialpositionofthe objectwithrespecttot

39、heprojectionplane),sothat thevanishingpointforthoseedgesparalleltothe projectionplaneissituatedatinfinityandthevanish ingpointforthoseedgesperpendiculartotheprojec tionplaneisthemainpoint(seefigure11). 7.2.2TracepointvanishingpointmethodB (particularpositionoftheobject) InmethodB,horizontalfacesofth

40、eobjectareper pendiculartotheverticalprojectionplane(particular positionoftheobjectwithrespecttotheprojection plane)sothatthelinesarerepresentedbytheirtrace ontheprojectionplaneandbytheirvanishingpoint (seefigure12). Figure11Object,framedinacube(indicatedbyadoubledashedline),inspecialposition withre

41、specttotheprojectionplaneaccordingtomethodAOSI ISO54564:1996(E) 11 Figure12Object,framedinacube(indicatedbyadoubledashedline),inparticularposition withrespecttotheprojectionplaneaccordingtomethodBISO54564:1996(E) OSI 12 7.3Distancepointmethod (specialpositionoftheobject) Thedistancepointmethodgivest

42、hecentralprojection ofanobjectwithoutitsbasicplane,bysettingupa perspectivegrid.Theoutlinesandedgesareparallel orperpendiculartotheprojectionplane(specialposi tion).Thedistancepointhasthesamedistancefrom themainpointastheprojectioncentrefromthe projectionplane.Allhorizontallinesinclinedat45 withresp

43、ecttotheprojectionplanealigntothedis tancepoint.Thevanishingpointofthedepthlinesof thegridisthemainpoint(seefigure13). Figure13Object,framedinacube(indicatedbyadoubledashedline),inspecialposition withrespecttotheprojectionplaneOSI ISO54564:1996(E) 13 7.4Scalepointmethod (particularpositionoftheobject) Foranyvanishingpointthereisacorrespondingscale point.Withtheaidofscalepoints,certaindimensions oftheobjecttobedepictedmaybetransferredfrom thebasiclineintheprojectionplaneondepthlines (seefigure14).Bymeansofthebas