[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： =w`Mc\o"  
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RPC Photonics公司有高品质的的工程漫射体BSDF测试数据，但它对于FRED帮助甚少，下面这个步骤描述了如何利用FRED脚本转换RPC Photonics提供的TXT文件，并将数据直接应用到FRED的Tabulated scatter 散射模型。 }V]*FCpQ  
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背景： c) Eu(j\#  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。  IZrcn  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 4x ?NCD=k  
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步骤 ajkV"~w',|  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 K 'I6iCrD  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） kKRu]0J~[  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 Tp@Yn  
例如下所示： X"3p/!W.4  
Sample name:  EDF-C1-56 )'jGf;du  
Merging data from file EDF-C1-56 0-0.txt cFie;k  
Finished merging RPC data for sample EDF-C1-56 ,eTdQI;   
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt `yq) y>_  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 H,<CR9@(5d  
a. 创建一个新的散射库 7kD?xHpe  
b. 散射模型命名 +|;Ri68  
c. 改变散射模型为“Tabulated BSDF”.
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d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 8oUR/___  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 sRLjKi2D  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， BO}IN#  
g. 点击OK Q0`@=5?-  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Ho}*Bn~i
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脚本代码： d$o m\@  
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'#Language "WWB-COM" o1 27? ^  
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Option Explicit jCj8XM{c>  
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Sub Main k~;~i)Eg  
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    'Cleanup Dd0yQgCu  
    ClearOutputWindow() 3v$n}.  
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    Print "Merging RPC Photonics BSDF Data Files" o9ys$vXt*  
    SetTextColor(255,0,0) Z 9cb  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 9*JxP%8T~X  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 6(\-aH'Ol  
    SetTextColor(0,0,0) S&=@Hj-  
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    'Current directory of this script (should be the same as the text files being merged) ej7N5~!,s  
    Dim cDir As String g<F+Ldgj  
    cDir = MacroDir$ & "\" \{rhHb\|h  
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    'Array which will be populated with the list of files to be merged VwBw!,%Ab  
    Dim fList() As String, curFile As String oT:wGBW  
    GetFileList( cDir, fList ) ?N+pWdi  
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    Print "" {a>JQW5=  
    Print "Files found for merging:" 4`5W] J]6  
    For Each curFile In fList =.J>'9Q  
        Print Chr(9) & curFile Grw[h  
    Next V[^AV"V  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. \Rt>U|%  
    Dim nameArray() As String, sampName As String 7!o
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    nameArray = Split(fList(0)," 0-0.txt") D}{]5R  
    sampName  = nameArray(0) O d6'bO;G  
    Print "" wko9tdC=U  
    Print "Sample name: " & Chr(9) & sampName !}`[s2ji  
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    'Open an output file and write the FRED header data m-[xrVV  
    Dim outFile As String tT A  
    outFile = cDir & sampName & "_FRED.txt" ),o=~,v:  
    Open outFile For Output As #1 DjZTr}%q  
    Print #1, "type bsdf_data" /a$Zzs&xs  
    Print #1, "format angles=deg bsdf=value scale=1" .ezko\nU  
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    'Loop the file list, skip the two header lines and write the remaining data to file HA$7Q~{N-t  
    Dim lineArray() As String, curLine As Long otdv;xI9  
    For Each curFile In fList Q^Vch(`&P  
        Print "Merging data from file " & curFile =L"I[  
        ReadFile( cDir & curFile, lineArray ) INCanE`+  
        For curLine = 2 To UBound(lineArray) Mu" vj*F  
            Print #1, lineArray(curLine) H11@ DQ6  
        Next frQ=BV5%6  
    Next q`|E9  
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    'Close the output file !}eq~3  
    Close #1 vl`St$$|  
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    Print "Finished merging RPC data for sample " & sampName bL:+(/:  
    Print "FRED formatted data file: " & Chr(9) & outFile *rm
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End Sub tuo'Uk)  
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'Utility function to read the contents of a file into an array of strings. xy)W_~Mk  
Function ReadFile(ByVal fileName As String, _ A,#z_2~  
                  ByRef lineArray() As String) As Long  OtZtl*5  
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    ReadFile = -1 F9IPA%  
    Dim oFSO As Object ~vZ1.y4  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 0KZsWlD:L  
    Erase lineArray *z'Rl'j9[  
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    Dim fid As Long X-"0Zc  
    If oFSO.fileexists( fileName ) Then :'!_PN  
        fid = FreeFile() LKud'  
        Open fileName For Input As fid >u`Ci>tY  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) rG B*a8  
        Close fid Ys5Iqj=mp  
    End If |z)7XK  
    Set oFSO = Nothing SwH#=hg  
    Return UBound( lineArray ) T!pHT'J  
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End Function :r_/mzR#  
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Sub GetFileList( ByVal in_dir As String, _ 0w$1Yx~C  
                 ByRef in_flist() As String ) *u34~v16,  
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    'Redimension the file list array y$|OE%S  
    Erase in_flist U,`F2yD/!  
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    'Tracks how many files are found K+U0YMRmz  
    Dim fCount As Long %C
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    fCount = 0 $O9#4A;  
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    'Recurse directory and search for text files HxShNU  
    Dim f As String y(r(q  
    f = Dir$(in_dir & "*.txt") LC/%AbM  
    While f <> "" )]JQlm:H  
        ReDim Preserve in_flist(fCount) 4=;`\-7!  
        in_flist(fCount) = f Or()AzwE@  
        fCount += 1 ]!N|3"Ls  
        f = Dir$() 3_Re>i  
    Wend Xu[A,6  
    ReDim Preserve in_flist(fCount-1) U$IB_a
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End Sub 4V5h1/JPm