[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： Zg+.`>z  
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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。 eD*764tG  
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背景： ^#5'` #t  
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。 o[;P@F  
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。 XfcYcN  
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步骤 zC*FeqFL<  
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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。 ?y|&Mz'XJ(  
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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） ivo3pibk%  
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 $HwF:L)*  
例如下所示： 5bb#{?2i  
Sample name:  EDF-C1-56 5c5!\g~'  
Merging data from file EDF-C1-56 0-0.txt F2YBkwI  
Finished merging RPC data for sample EDF-C1-56 P$'PB*5d|  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt :[a*I6/^  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 g9C-!X-<T  
a. 创建一个新的散射库 s(_z1  
b. 散射模型命名 C b'|  
c. 改变散射模型为“Tabulated BSDF”. ^E%R5JN  
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 ） qiOtbH=  
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。 gV)/lDEM5  
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， WvU[9ME^)  
g. 点击OK b GSj?t9/  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 aPJTH0u  
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脚本代码： D[^K0<-Z  
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'#Language "WWB-COM" )d[n-Si  
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Option Explicit )pI( <  
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Sub Main @zGF9O<3,@  
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    'Cleanup o2|#_tGNUy  
    ClearOutputWindow() WG,
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    Print "Merging RPC Photonics BSDF Data Files" e&ti(Q=  
    SetTextColor(255,0,0) sssw(F  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." }^I3
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." -sHX  
    SetTextColor(0,0,0) %nJo:/  
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    'Current directory of this script (should be the same as the text files being merged) 9@qkj 4w  
    Dim cDir As String uznqq}  
    cDir = MacroDir$ & "\" -75mgOj.#  
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    'Array which will be populated with the list of files to be merged )E9c6'd  
    Dim fList() As String, curFile As String 'xd8rN%T  
    GetFileList( cDir, fList ) h_-4Q"fb(  
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    Print "" .Z]hS7t  
    Print "Files found for merging:" .3) 27Cjw  
    For Each curFile In fList idHI)6!  
        Print Chr(9) & curFile nK< v
  
    Next ]@y%j'e  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. y?cN  
    Dim nameArray() As String, sampName As String ftmPdha%+  
    nameArray = Split(fList(0)," 0-0.txt") zWPX  
    sampName  = nameArray(0) ,g'>
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    Print "" ,J2qLH1  
    Print "Sample name: " & Chr(9) & sampName [PXq<ST  
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    'Open an output file and write the FRED header data 8@ f!,!Wn  
    Dim outFile As String 7"Nd
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    outFile = cDir & sampName & "_FRED.txt" C-ORI}o  
    Open outFile For Output As #1 {Zw;<1{E  
    Print #1, "type bsdf_data" ElTB{C>u  
    Print #1, "format angles=deg bsdf=value scale=1" "Plo[E  
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    'Loop the file list, skip the two header lines and write the remaining data to file ).HA#!SE  
    Dim lineArray() As String, curLine As Long ].Bx"L!B  
    For Each curFile In fList zT}vaU6  
        Print "Merging data from file " & curFile VJ h]j(  
        ReadFile( cDir & curFile, lineArray ) )AEtW[~D  
        For curLine = 2 To UBound(lineArray) g/l:q&Q<  
            Print #1, lineArray(curLine) K%`]HW@I{  
        Next >+<b_q|P  
    Next Px-VRANZt  
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    'Close the output file bD/ZKvg  
    Close #1 PN99 R]K0g  
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    Print "Finished merging RPC data for sample " & sampName 3O4,LXdA  
    Print "FRED formatted data file: " & Chr(9) & outFile f.j
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End Sub yX*$PNL5w  
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'Utility function to read the contents of a file into an array of strings. GwXhn2  
Function ReadFile(ByVal fileName As String, _ jLn#%Ia}  
                  ByRef lineArray() As String) As Long RIUJX{?  
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    ReadFile = -1 Hr=|xw8.  
    Dim oFSO As Object G*_
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    Set oFSO = CreateObject("Scripting.FileSystemObject") =mX26l`B  
    Erase lineArray T9J&^I  
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    Dim fid As Long J9t?;3  
    If oFSO.fileexists( fileName ) Then a0k;way  
        fid = FreeFile() %H{;wVjK  
        Open fileName For Input As fid du'`&{_/  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 'y>Y*/  
        Close fid s5G`?/  
    End If Uu*iL< `  
    Set oFSO = Nothing [%yj' )R/  
    Return UBound( lineArray ) [;yH.wn#5  
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End Function `<~=6H  
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Sub GetFileList( ByVal in_dir As String, _ SAitufS  
                 ByRef in_flist() As String ) 4 7mT  
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    'Redimension the file list array $"( 15U  
    Erase in_flist B#IUSHC  
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    'Tracks how many files are found )l! /7WKY  
    Dim fCount As Long {U>N*&_`  
    fCount = 0 lw~ V  
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    'Recurse directory and search for text files CLmo%"\s  
    Dim f As String rp"5176  
    f = Dir$(in_dir & "*.txt") :JX2GRL4  
    While f <> "" uD?G\"L i  
        ReDim Preserve in_flist(fCount) oj{CNa  
        in_flist(fCount) = f 479X5Cl  
        fCount += 1 #C.  
        f = Dir$() ,W[J@4.  
    Wend )qMbk7:v\  
    ReDim Preserve in_flist(fCount-1) {ir
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} LC  
End Sub {Ak 4GL