[分享]RPC Photonics扩散片BSDF [复制链接]

摘要： _I`,Br:N  
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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。 X
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背景： ?&LZB}1R  
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。 g*)K/Z0pJ$  
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。 k:2QuG^  
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步骤 hUQ,z7-  
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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。 GLn{s  
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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）
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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 ri`R<l8  
例如下所示： +_v$!@L8  
Sample name:  EDF-C1-56 x:vu'A  
Merging data from file EDF-C1-56 0-0.txt <2!v(EkI  
Finished merging RPC data for sample EDF-C1-56 lf>*Y.!@me  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt GU't%
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4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ]sz
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a. 创建一个新的散射库 kt[:@Nda9  
b. 散射模型命名 xvzr:pP  
c. 改变散射模型为“Tabulated BSDF”. Q6o(']0  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） E^GHVt/.  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 >@WX>0`ht  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， 7&`}~$>}>e  
g. 点击OK I -Xlx<  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 A*./,KT  
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脚本代码： i{!
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'#Language "WWB-COM" O8|5KpXd@  
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Option Explicit $F.([?)k?  
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Sub Main d=,%=@  
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    'Cleanup LG~S8u  
    ClearOutputWindow() ZpUCfS)|&  
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    Print "Merging RPC Photonics BSDF Data Files" ^gV
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    SetTextColor(255,0,0) c4_`Ew^k  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." P5lqSA{6  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." iv phlw  
    SetTextColor(0,0,0) ^:9
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    'Current directory of this script (should be the same as the text files being merged) 7&KT0a*  
    Dim cDir As String /h v4x9  
    cDir = MacroDir$ & "\" h25G/`  
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    'Array which will be populated with the list of files to be merged kc/{[ME  
    Dim fList() As String, curFile As String \%sVHt`c  
    GetFileList( cDir, fList ) @fuM)B1"  
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    Print "" o!:8nXw  
    Print "Files found for merging:" p8
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    For Each curFile In fList Z/^
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        Print Chr(9) & curFile s>0Nr  
    Next e4~>G?rM_  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. j)t+jcMUI  
    Dim nameArray() As String, sampName As String tBTTCwNT%  
    nameArray = Split(fList(0)," 0-0.txt") tpy>OT$  
    sampName  = nameArray(0) 0l;<5  
    Print "" _"4xKh)  
    Print "Sample name: " & Chr(9) & sampName `h}q Eo`  
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    'Open an output file and write the FRED header data 0Z|FZGRP  
    Dim outFile As String FWH}j0Gj|  
    outFile = cDir & sampName & "_FRED.txt" ^m
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    Open outFile For Output As #1 lTU$0CG  
    Print #1, "type bsdf_data" R),zl_d_  
    Print #1, "format angles=deg bsdf=value scale=1" zqDR7+]  
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    'Loop the file list, skip the two header lines and write the remaining data to file c9R5w.t:  
    Dim lineArray() As String, curLine As Long "P)*FT  
    For Each curFile In fList K7
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        Print "Merging data from file " & curFile yqSs,vz  
        ReadFile( cDir & curFile, lineArray ) y*{Zbz#{  
        For curLine = 2 To UBound(lineArray) DO7W}WU  
            Print #1, lineArray(curLine) vK$"# F~  
        Next N_L,]QT?  
    Next ,@m@S^  
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    'Close the output file A]L%dFK  
    Close #1 iCP/P%  
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    Print "Finished merging RPC data for sample " & sampName 4@.|_zY  
    Print "FRED formatted data file: " & Chr(9) & outFile :S$l"wrh\  
End Sub Pmi#TW3X  
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'Utility function to read the contents of a file into an array of strings. ~x{.jn  
Function ReadFile(ByVal fileName As String, _ &'l>rD^o  
                  ByRef lineArray() As String) As Long zi~5l#I  
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    ReadFile = -1 `[zQf  
    Dim oFSO As Object pf4 ^Bk}e  
    Set oFSO = CreateObject("Scripting.FileSystemObject") _= #zc4U  
    Erase lineArray ::n;VY2&  
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    Dim fid As Long A?TBtAe  
    If oFSO.fileexists( fileName ) Then @H!$[m3  
        fid = FreeFile() zo;^m|  
        Open fileName For Input As fid 5>6PH+Oq  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 5unG#szq  
        Close fid Q4t(@0e}  
    End If xUF_1hY  
    Set oFSO = Nothing ;X,1&#I  
    Return UBound( lineArray ) 5-)#f?  
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End Function _WX#a|4h{  
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Sub GetFileList( ByVal in_dir As String, _ /S:F)MO9  
                 ByRef in_flist() As String ) )m3q2W  
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    'Redimension the file list array tU"raP^=  
    Erase in_flist 2!N8rHRt  
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    'Tracks how many files are found ,n!vsIN  
    Dim fCount As Long 4E44Hzs  
    fCount = 0 "i:T+#i({O  
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    'Recurse directory and search for text files iAY!oZR(WT  
    Dim f As String hP J4Oj1O  
    f = Dir$(in_dir & "*.txt") )o!XWh  
    While f <> "" j
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        ReDim Preserve in_flist(fCount) MJj4Hd  
        in_flist(fCount) = f %7Kooq(i  
        fCount += 1 >]'yK!a?  
        f = Dir$() \qsw"B*tv`  
    Wend  TIy&&_p  
    ReDim Preserve in_flist(fCount-1) m?s}QGSka  
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End Sub W;?(,xx  
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