[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： s1v{~xP  

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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。 .;j"+Ef   
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背景： wb@]>MJ}[s  
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。 hOV_Oqe4?  
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。 'oT|cmlc  
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步骤 )y5iH){!  
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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。 cx<h_  
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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） \:C%> .VG  
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 5'),)  
例如下所示：
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Sample name:  EDF-C1-56 .!9Vt#  
Merging data from file EDF-C1-56 0-0.txt P%ye$SASd  
Finished merging RPC data for sample EDF-C1-56  hgNY[,  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt e-1;dX HL  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 D_zcOq9  
a. 创建一个新的散射库 #dL5x{gV=  
b. 散射模型命名 K T%i,T  
c. 改变散射模型为“Tabulated BSDF”. P:jDB{  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 9j9YQ2  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 3@%BA(
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f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， -<H ri5  
g. 点击OK q=J9LQ  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 }7otuO(pRo  
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脚本代码： /abmjV0  
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'#Language "WWB-COM" 9T?~$XlX  
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Option Explicit 9@JlaY)0  
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Sub Main Zjw
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    'Cleanup ':5Trx  
    ClearOutputWindow() gF$1wV]e  
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    Print "Merging RPC Photonics BSDF Data Files" ,ZsYXW  
    SetTextColor(255,0,0) qQwJJjf  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." mrw]yu;2<n  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." |k/`WC6As.  
    SetTextColor(0,0,0) oSpi{ $x  
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    'Current directory of this script (should be the same as the text files being merged) {Q}!NkF1  
    Dim cDir As String OaX HJ^k  
    cDir = MacroDir$ & "\" #JHy[!4  
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    'Array which will be populated with the list of files to be merged GGYX!=]~  
    Dim fList() As String, curFile As String 7O;BS}Lv=  
    GetFileList( cDir, fList ) =ip~J<sw&  
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    Print "" y
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    Print "Files found for merging:" L{+&z7M  
    For Each curFile In fList N` @W%  
        Print Chr(9) & curFile 3tJ=d'U  
    Next Tw`
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. FY_avW  
    Dim nameArray() As String, sampName As String &;SwLDF"1  
    nameArray = Split(fList(0)," 0-0.txt") 5P5A,K  
    sampName  = nameArray(0) H5F\-&cq  
    Print "" LZ=wz.'u  
    Print "Sample name: " & Chr(9) & sampName jV(xYA
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    'Open an output file and write the FRED header data a>;3 j  
    Dim outFile As String 'Qp&,xK  
    outFile = cDir & sampName & "_FRED.txt" 9b"}CEw  
    Open outFile For Output As #1 kMfc"JXF  
    Print #1, "type bsdf_data" :pL1F)-*  
    Print #1, "format angles=deg bsdf=value scale=1" ,)B~ci
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    'Loop the file list, skip the two header lines and write the remaining data to file ox i a}  
    Dim lineArray() As String, curLine As Long W>aQ tT  
    For Each curFile In fList r_!{!i3B  
        Print "Merging data from file " & curFile MbT ONt?~v  
        ReadFile( cDir & curFile, lineArray ) KNO*)\
  
        For curLine = 2 To UBound(lineArray) +R{A'Yl[(  
            Print #1, lineArray(curLine) 8gu'dG=  
        Next i{1)=_$Vt`  
    Next .P|+oYT&g  
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    'Close the output file )D6'k{6M  
    Close #1 XC+F! R  
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    Print "Finished merging RPC data for sample " & sampName Mdy0!{d  
    Print "FRED formatted data file: " & Chr(9) & outFile BJ:E,P`_  
End Sub HlOAo:8'  
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'Utility function to read the contents of a file into an array of strings. x`j$9XN5  
Function ReadFile(ByVal fileName As String, _ eE#81]'6a  
                  ByRef lineArray() As String) As Long 7>W+Uq  
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    ReadFile = -1 5~ *'>y  
    Dim oFSO As Object 'aSZ!R  
    Set oFSO = CreateObject("Scripting.FileSystemObject") &\WkJ}&PnA  
    Erase lineArray M;S-ESQ  
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    Dim fid As Long 0IT20.~  
    If oFSO.fileexists( fileName ) Then
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        fid = FreeFile() b6?Xo/lJ.  
        Open fileName For Input As fid z</XnN  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) $Nt]${0  
        Close fid SzgY2+Qq  
    End If w'5dk3$"  
    Set oFSO = Nothing K_<lO,[S  
    Return UBound( lineArray ) $fj"*   
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End Function ] fwTi(4y  
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Sub GetFileList( ByVal in_dir As String, _ @Z=y'yc'y.  
                 ByRef in_flist() As String ) /%}YuN  
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    'Redimension the file list array Tg{dIh.Q~O  
    Erase in_flist wZ\e3H z  
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    'Tracks how many files are found o}AqNw60v  
    Dim fCount As Long J~yd]L>  
    fCount = 0 =Y=^]ayO/  
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    'Recurse directory and search for text files CB{k;H  
    Dim f As String B#Oc8`1Y  
    f = Dir$(in_dir & "*.txt") +=29y@c  
    While f <> "" ?XTg%U  
        ReDim Preserve in_flist(fCount) ^JF_;~C  
        in_flist(fCount) = f ke;*uS  
        fCount += 1 7K5
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        f = Dir$() pFv[z':&Q  
    Wend H$qdU!c  
    ReDim Preserve in_flist(fCount-1) 6Kv}2M')+  
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End Sub  qzU2H