vray渲染基础教程（vray渲染基础教程）

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vray渲染基础教程（vray渲染基础教程）vraymtlparameters（vray材质参数）vraymtl（vray材质）是vray渲染系统的专用材质•使用这个材质能在场景中得到更好的和正确的照明（能量分布），更快的渲染，更方便控制的反射和折射参数•在vraymtl里你能够应用不同的纹理贴图,更好的控制反射和折射，添加bump（凹凸贴图）和displacement（位移贴图），促使直接gi（im）计算，对于材质的着色方式可以选择brdf（毕奥定向反射分配函数）.详细参数如下.basicparameters（基本参数）（漫反射）is材质的漫反射颜色•你能够在纹理贴图部分（texturemaps）的漫反射贴图通道凹槽里使用一个贴图替换这个倍增器的值.（反射）Which—个反射倍增器（通过颜色来控制反射，折射的值.你能够在纹理贴图部分（texturemaps）的反射贴图通道凹槽里使用一个贴图替换这个倍增器的值）.glossiness（光泽度、平滑度）-这个值表示材质的光泽度大小.值为0.0意味着得到非常模糊的反射效果•值为1.0,将关掉光泽度（vray将产生非常明显的完全反射）•注意：打开光泽度（glossiness）将增加渲染时间.subdivs（细分）-控制光线的数量，作出有光泽的反射估算.当光泽度（glossiness）值为1.0时，这个细分值会失去作用（vray不会发射光线去估算光泽度）.当这个选项给打开时fresnelreflection（菲涅尔反射），反射将具 有真实世界的玻璃反射•这意味着当角度在光线和表面法线之间角度值接近0度吋，反射将衰减（当光线几乎平行于表面吋，反射可见性最大•当光线垂直于表面时几乎没反射发生.maxdepth（最大深度）-光线跟踪贴图的最大深度•光线跟踪更大的深度时贴图将返回黑色（左边的黑块）.refract（折射（texturemaps）一个折射倍增器•你能够在纹理贴图部分的折射贴图通道凹槽里使用一个贴图替换这个倍增器的值.glossiness（光泽度、平滑度）-这个值表示材质的光泽度大小.值为0.0意味着得到非常模糊的折射效果•值为1・0,将关掉光泽度（vray将产生非常明显的完全折射）.subdivs（细分）-控制光线的数量，作出有光泽的折射估算.当光泽度（glossiness）值为1.0时，这个细分值会失去作用（vray不会发射光线去估算光泽度）.ron（这个值确定材质的折射率.设置适当的值你能做出很好的折射效果象水、钻石、玻璃等等折射率）.translucent（半透明）-打开半透明性.注意：你的灯光必需有vrayshadows设置，并且它下面的translucency要勾选.glossy也必须打开.vray将使用雾的颜色（fogcolor）来判定光的数量经过一个框架穿过材质下的面（passes）・this这个值确定半透明层的厚度•当光线跟踪深度达到这个值时（厚度）,vray不会跟踪光线更下面的面.lightmore灯光分摊用的倍增器•用它来描述穿过材质下的面被反、折射的光的数量灯光倍增器）. scatterfactor（散射效果控制）这个值控制在半透明物体的表面下散射光线的方向•值为0.0时意味着在表面下的光线将向各个方向上散射；值为1・0时，光线跟初始光线的方向一至.Scatteringthroughobjects・Fwd/bckcoeff(forward/backwardcontrol)-thisvaluecontrolshowmuchofthescatteredlightbelowthesurfaceofthesemitransparentobjecttravelsthroughtheobjectrelativetotheoriginallight,forwardorbackward.Avalueof1meansthatalllightwilltravelforward;whenthevalueis0,allthelightwillpropagateback;whenthevalueis0.5,thelightisdistributedintheforward/backwarddirection.Fogcolor(fogcolor)-VRayallowsyoutofillarefractedobjectwithfog.Thisisthecoloroffog・Fogmultiplier(fogmultiplier)-fogcolormultiplier・Smallervaluesproducemoretransparentfog・BRDF(Biotdirectionalreflectancedistributionfunction)Oneofthemostcommonmethods・BasedonBiotdirectionalreflectiondistributionfunction(BRDF)wasusedtorepresentthereflectancepropertiesofasurface・Afunctionthatdefinesthespectralandspatialreflectancepropertiesofasurface・VRaysupportsthefollowingBRDFtypes:Phong,BLinn,Ward.Options(option)Tracereflections(trackingreflex)-reflexswitch・ Tracerefractions(tracerefraction)-refractionswitch・Useirradiance,map,if,On,GI(usingphotondiagramopen)-whenyouuseGI(photondiagram)irradiancemap,youcanstillusethebruteforcefortheobject'smateria1.Tocompletetheserequirements,turnofftheUseirradiancemapifOnoption.Otherwise,GIwillusetheirradiancemap・fortheobjecttousethismateria1.NotethatunlesstheGIisopenedandtheIrradiancemapisset,thisoptiondoesnotwork・Tracediffuse&glossytogether(diffuseGloss&followup)-whenthereflection/refractionglossisopened,VRayusesmanylighttotracktheglosswhileanotherisusedtocalculatethediffusecolorlight・OpenthisoptiontoforcetheVRaytotrackbrightnessordiffusetheindividuallightofthetwomaterialcomponents・Inthiscase,VRaywillexecuteoneoftheestimatesandpicksomeraytracingdiffusecomponents,andtherestoftheraytracedtrackinggloss(glossiness)・Double-sided(doublesided)-thisoptionVRayassumesthatallgeometrysurfacesaretwo-sided.Reflectonbackside(backreflection)-thisoptionforcestheVRaytoalwaysfollowthereflection(eventhebackofthesurface)・Note:onlywhenyouopenit(theReflectonbackside)willthebackreflectionwork・Cutoff(cut-offshear)一thisisthereflection/refractionthreshold・Thereflection/refractionwillnotbetracedwhenthereflection/refractiontakesaneffectonthefinalvalueofanimagesamplin£・WhentheCutoffissettotheminimum,thereflection/refractionistraced・ Texturemaps(texturemapping)Inthissection,youcansetdifferenttexturemaps・TheavailabletexturemapchannelslotsareDiffuse,Reflect,Refract,Glossiness,Bump,and,Displace・Ineachtexturemapchannel,thereisamultiplier,astatuscheckbox,andalongbutton.Thismultipliercontrolstheintensityofthetexturemap.Statuscheckboxisthemapswitch・Thelongbuttonletsyouselectthetextureyouwantorchoosethecurrentmap・Diffuse(diffuse)-thischannel'sgroovecontrolsthediffusecolorofthemateria1.Ifyouonlyneedasimplecolormultiplier,youcanusethischannelslotinsteadandusethediffusesettingsinthebaseparametercolumninstead・Reflect(reflection)-thistexturemapcontrolsthereflectioncolormultiplierofthematerialinthegrooveofthischanne1.Ifyouonlyneedasimplecolormultiplier,youcanusethischannelwithoutusingthechanneTsshadowandusethemirrorsettingsinthebaseparametercolumninstead・Glossiness(GuangZedu)-thistexturemapisusedasamultiplierforglossy,smoothreflectioninthischannel'sgroove・Refract(refraction)-thistexturemapcontrolstherefractivecolormultiplierofthematerialinthischannelslot・Ifyouonlyneedasimplecolormultiplier,youcanusethischannelslotinsteadandusetherefractionsettingsinthebasicparameterbartoreplaceit.Glossiness(GuangZedu)-thistexturemapisusedasamultiplierforglossy,smoothrefractioninthechanneTsgroove. Bump(bumpmap)-thisisthebumpchannelgroove・Thisbumpmapisusedtosimulatethesurfaceroughness(roughnessroughness)anddoesnotreallyaddmoregeometrytothescenetosimulatetheroughnessofthesurface・Displace(displacementmapping)-thisisthegrooveofthedisplacementmapchanne1.Thedisplacementmapisappliedtosurfacemodeling,soitlooksmorerugged.Unlikebumpmaps,displacementmapsactuallyperformsubdivisionofthesurfaceanddisplacementofnodes(changinggeometry)・Itslowsdownrelativetobumpmapping・VRayLightparameters(VRaylightparameters)ThissectiondescribestheparametersthatcontroltheVRaylightlightsource・On-VRaylightswitch・Double-sided(double)-whentheVRaylightisasurfacelightsource,thisoptioncontrolswhetherthelightgeneratesbeamsonbothsidesofthelightsource・ThisoptionwillnotworkwhentheSpherelightsourceisselected.Transparent(transparent)-thissettingcontrolswhethertheVRaylightsourcedisplaysitsshapeintherenderresult・(defaultisdisplayed)Ignorelightnormals(ignoringthelightsourcenormal)-whenatrackedlighthitsthelightsource,thisoptionallowsyoutocontrolthewayVRayhandiescomputation.Accordingtothereal worldlight,thisoptionshouldbeturnedoff.Anyway,whenthisoptionopens,therenderresultmaybesmoother・Normalizeintensity(standardbrightness)-whenthebrightnessnormalizationisturnedon,thesizeofthelightsourcewillnotaffectitsbrightness・Thisbrightnesswillbethesameasthesizeofthelightsourcefor1.note:beforeopeningbrightnessnormalization,itisusefulforsettingvaluesofsize1andMult・sothatyoucangetthedesiredbrightness・ThenturnontheNormalizeintensityandchangethesizeofthelightsourceasdesired・Thisbrightnesswillbepreservedequal1y.(opensallblackL,don'tunderstandsopaytheoriginalNote:beforeenablingintensitynormalizationitisusefultosetthesizetotheMult・valueaccordingly1andsothattoachievethedesiredintensity・ThenturnNormalizeintensityonandchangethesizeofthelightsourceasdesired・Theintensitywillstaythesame・)Nodecay(noattenuation)-whenthisisturnedon,theVRaylightwillnotdecay.Otherwise,thelightwillbeattenuatedinthereversesquared(inverse,square)distance・(thisisthewaythelightdecaysintherealworld・)Storewithirradiancemap(storageradiationmap)-thiswasopened,andthecalculationofGIset(Irradiancemap)radiationmapVRaywillrecalculatetheVRaylightingeffectsandstorethemforradiationmaps(irradiancemap)・Theresultisthattheradiationmapiscomputedmoreslowly,butspendslesstimerendering・Youcansavethemapirradiance(the)anduseitlater・Color(color)-thelightcoloremittedbyaVRaylightsource・ Mult・(multiplier)一aVRaylightcolormultiplier・Type(type)Plane(lightsource)-afterthelightsourcetypeisselected,theVRaylighthasaplaneshape・Sphere(spherelightsource)-afterthelightsourcetypeisselected,theVRaylighthasasphericalshape・Size(size)Usize(Usize)-sourceUsize(iftheSpherelightsourceisUsizeisequaltotheradiusofthesphere)・Vsize(Vsize)-sourceVsize(whentheSpherelightsourceisselectedthisoptionwillnotwork)・Wsize(Wsize)-sourceWsize(whentheSpherelightsourceisselectedthisoptionwillnotwork)・Sampling(sampling)Subdivs(subdivision)-thisvaluecontrolsthenumberofsampling・VRaytakesthisvaluetocalculatethelight・Lowsubdivs(lowsubdivision)-thisvaluecontrolsthenumberofsampling・Whenthelowaccuracy(lowaccuracyComputation)isconsidered,VRaytakesthisvaluetocalculatethelight・Degradedepth(downgradedepth)-whenVRayisswitchedtolow accuracy(lowaccuracycomputations・)whenthisvaluewillindicatethedepthofraytracing・VRayLightexamples(VRaylightforexample)Theimagebelowshowshowthespheresourceradiusobjectshadow.InordertokeepthelightsinthesceneofthebrightnessoftheNormalizeintensityisopen(butafteropeningYou'11see・L),regardlessofthesizeofthelightsource・Transparent二off,Ignore二lightnormalsoffNormalizeintensityNo二on,decay二off,Color(255255255),Subdivs二10,Low二1subdivsdepth二2,Degrade,Sphere・Thefollowingimagedemonstrationisasurfacelightsource・Thepublicparameters:Transparent二off,Ignore二lightnorma1soffNormalizeintensityNo二on,decay二off,Color(255255255),Subdivs二10,Low二1subdivsdepth二2,Degrade,Sphere・Theimagebelowisnotdecaymodel(nodecay)・Intherealworldistolightattenuationtoinversesquaredistance・YoucanturnoffthelightattenuationintheVRaytoproduceacertaineffect・Thefollowingisatwopicturesetthesamelightsourceontheleft・