美國人的汽車畫法

1、Evaluation Warning: The document was created with Spire.Doc for .NET.外國人的汽車畫法Drawiing ElllipssesAnatoomy of an elllipsse: Wheen wwe vvieww a cirrclee att ann annglee wee seee aan eelliipsee. WWe rrefeer tto tthiss viiewiing anggle as thee deegreee oof tthe elllipsse. A pperffectt ciirclle iis vvieww

2、ed at 90 deggreees aand at anggless leess thaan tthatt wee seee vvariiouss deegreee eelliipsees oon tthe wayy doown to a zzeroo deegreee eelliipsee (aa sttraiightt liine). UUndeersttanddingg thhe mmechhaniics of draawinng eelliipsees iis nnot diffficcultt, mmastteriing thee drrawiing of elllipsses i

3、s. Ann elllippse hass twwo aaxess wee neeed to knoow aabouut, thee miinorr axxis andd thhe mmajoor aaxiss. TThe minnor axiis ddiviidess thhe eelliipsee innto twoo eqquall haalvees aacrooss itss naarroow ddimeensiion. Thhe mmajoor aaxiss diividdes thee elllippse acrrosss itts llongg diimennsioon iint

4、oo twwo eequaal hhalvves. Thhe mminoor aand majjor axees ccrosss eeachh ottherr att a 90 deggreee annglee. SSee draawinng ee-1. If wee loook at thee drrawiing in e-22 wee caan ssee thaat II haave draawn a ssquaare arooundd ouur eelliipsee. AAfteer II drraw thee sqquarre II drraw an “X” acrrosss itt

5、too fiind itss ceenteer iin ppersspecctivve. Wheen yyou obsservve tthe minnor andd maajorr axxes of thee elllippse we seee thhat thee miinorr axxis goees tthrooughh thhe ccentter of thee sqquarre wwhille tthe majjor axiis ddoess noot. We alsso oobseervee thhat thee elllippse touuchees ttanggentt exx

6、acttly in thee miiddlle oof eeachh siide of thee sqquarre, exaactlly wwherre wwe wwoulld eexpeect it to. Thhis is a bbit of a mmindd beendeer. We havve ttakeen aa syymmeetriicall shhapee, tthe elllipsse, andd drroppped it intto ppersspecctivve. Thiis aalwaays worrks if youu doo yoour draawinng wwith

7、hin thee alllowwablle llimiits of disstorrtioon. Reggarddlesss oof wwhettherr yoour elllipsse iis rrolllingg onn thhe ggrouund or resstinng oon iit, as we seee inn drrawiing e-33, tthe connstrructtionn reesullt rremaainss thhe ssamee. LLearrninng ffromm thhis obsservvatiion andd noow kknowwingg whhe

8、ree thhe mminoor aand majjor axees oof oour elllipsse sshouuld be is thee siinglle ggreaatesst hhelpp inn drrawiing elllipsses prooperrly. Siincee thhe eelliipsee miinorr axxis alwwayss gooes thrrouggh tthe cennterr off ouur ssquaare thiis iis ssomeethiing we cann usse tto hhelpp uss drraw it. Coonv

9、eerseely thee maajorr axxis reffereencees nnothhingg thhat cann heelp us in loccatiing it in ourr peersppecttivee sqquarre. Thiis iis wwhy I ddo nnot reccommmendd ussingg thhe mmajoor aaxiss whhen draawinng eelliipsees.PPraccticce ddrawwingg elllippsess wiithoout worrryiing aboout loccatiing theem i

10、in ppersspecctivve. Herre aare a ffew exaamplles of my russty armm trryinng tto ddraww soome elllipsses forr thhis tuttoriial thiis mmornningg. DDraww vaarioous sizzes andd diiffeerinng ddegrreess. AAfteer yyou draaw tthe elllipsse iidenntiffy iits minnor axiis bby ddrawwingg a linne aacrooss itss n

11、aarroow ddimeensiion thaat ddiviidess eaach sidde eequaallyy.find it hellpfuul iif yyou imaaginne tthatt yoou aare goiing to folld yyourr elllippse aloong thiis llinee. YYou wannt iit tto ffoldd allongg thhis linne aand lannd eexacctlyy baack on itsselff. IIf yyourr miinorr axxis is inccorrrectt wee

12、 caan ssee whaat hhapppenss inn drrawiing e-44. Afterr yoou aare feeelinng ggoodd abboutt hoow yyourr elllippsess arre llookkingg annd yyou aree coonfiidennt yyou cann loocatte tthe minnor axiis oof eeachh prropeerlyy yoou aare reaady to staart tryyingg too loocatte yyourr elllippsess wiithiin ppers

13、specctivve cconsstruuctiionss. SStarrt wwithh soometthinng ssimpple likke ddrawwingg a strraigght linne tthatt reepreesennts thee miinorr axxis of youur eelliipsee annd tthenn trry aand draaw eelliipsees oof vvariiouss siizess annd ddegrreess onn thhat linne. Thiis iis aa liittlle hhardder thaan ddr

14、awwingg thhe eelliipsee fiirstt annd tthenn drrawiing thee miinorr axxis. Affterr yoou nnaill thhat exeerciise tryy drrawiing twoo coonveergiing strraigght linnes andd drrawiing elllipsses thaat ttoucch ttanggentt too eaach linne. Thiis iis hhardder stiill. Onne oof tthe mosst ddiffficuult exeerciis

15、ess iss too drraw a ppagee off cuubess annd tthenn drraw an elllipsse oon eeachh faace thaat ttoucchess taangeent to thee siide of eacch ssquaare as we obsservved in draawinngs e-22 annd ee-3. Drrawiing conncenntriic eelliipsees aare alsso ggoodd prractticee. You ccan usee elllippse guiidess too stt

16、raiightten up youur eelliipsees bbut do nott trry tto sskettch witth tthemm. II haave yett too seee tthiss doone effficiienttly. Yoou aare mucch bbettter offf too doo alll oof yyourr peersppecttivee laayouut wworkk frreehhandd annd tthenn brreakk ouut tthe sweeepss annd eelliipsee guuidees tto ttigh

17、htenn thhinggs uup iif yyou neeed tto. Oncce yyou havve ppraccticced enooughh yoou wwilll fiind thaat yyou cann doo veery commpettentt drrawiingss enntirrelyy frreehhandd. TTherre iis aa grreatt seensee off saatissfacctioon tthatt coomess frrom achhievvingg niice linne qquallityy annd ppropper perrs

18、peectiive in a ffreeehannd sskettch. How tto cchecck iif yyourr elllippse is corrrecctlyy drrawnn. IIt iis iimpoortaant to unddersstannd tthe mecchannicss off elllippsess soo yoou ccan makke aadjuustmmentts tto tthemm affterr yoou hhavee drrawnn thhem. Baasiccallly ttherre aare onlly ttwo thiingss t

19、hhat makke aan eelliipsee eiitheer ppropperlly ddrawwn iin ppersspecctivve oor nnot.Minorr axxis andd yoour vannishhingg poointts. Thee fiirstt thhingg too chheckk iss whhethher youur mminoor aaxiss iss coorreect. Inn thhe ccasee off puuttiing wheeelss onn caars thee miinorr axxis is alwwayss coommo

20、on tto tthe axlle oof tthe wheeel. Moost of thee tiime thiis aaxlee iss allso perrpenndicculaar tto tthe cennterrlinne oof yyourr caar. So it folllowws tthatt thhe mminoor aaxess off yoour elllipsses (whheells) aree allso perrpenndicculaar tto tthiss ceenteerliine. Thheree arre ccasees ssuchh ass wh

21、hen thee frrontt whheells aare turrnedd orr thhe wwheeels havve bbeenn seet uup wwithh exxtreeme cammberr thhat theey aare no lonngerr peerpeendiicullar to thee ceenteerliine of youur vvehiiclee. AAnottherr eaasy exaamplle ffor us to vissuallizee iss thhat thee miinorr axxis of a pproppelller on an

22、airrplaane is parralllel to thee ceenteerliine of thee fuusellagee annd ttherrefoore theey ggo tto tthe samme vvaniishiing poiint. Reememmberr whhen perrspeectiive draawinng tthatt “aall parralllel linnes go to thee saame vannishhingg poointt”. Degreee oof yyourr elllippse. Asssummingg thhe mminoor

23、aaxiss off yoour elllipsse iis ccorrrectt annd yyourr elllippse stiill loooks wroong it cann bee onnly onee thhingg, tthe deggreee. BBefoore tryyingg too addjusst tthe deggreee off ann elllippse thee miinorr axxis musst bbe ccorrrectt. NNo aamouunt of adjjusttmennt tto tthe deggreee caan mmakee upp foor aan iincoorreect minnor axiis. Cheeckiing thee deegreee iis aa siimplle ppersspecctivve cconsstruuctiion. Steep 11: DDraww a boxx arrounnd aand tanngennt oon eeachh siide to youur eelliipsee. BBe ssuree too foolloow yyourr peersppecttivee guuideeli