[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： V;0{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。 hp=TWt~  
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背景： $.{CA-~%[  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 hd{Vz{;W  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 7yp7`|,p  
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步骤 ?g9mDe;k  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 :a$ZYyD  
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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） *AX)QKQ@  
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 uX_A4ht*  
例如下所示：
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Sample name:  EDF-C1-56 )P4#P2  
Merging data from file EDF-C1-56 0-0.txt rK&ofc]f$  
Finished merging RPC data for sample EDF-C1-56 ;m6Mm`[i
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FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt kB_uU !G  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 s!S,;H  
a. 创建一个新的散射库 Ch-56   
b. 散射模型命名 c*MSd  
c. 改变散射模型为“Tabulated BSDF”. *4}l
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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 ） Ya
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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。 b(&~f@%|  
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， V"":_`1VW  
g. 点击OK Y#'mALC2  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 qT]Bl+h2  
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脚本代码： #k? Rl  
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'#Language "WWB-COM" %4QCUc*lr  
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Option Explicit ?3 J  
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Sub Main cG
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    'Cleanup N!6{c
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    ClearOutputWindow() $s2
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    Print "Merging RPC Photonics BSDF Data Files" Yo0%5 noz  
    SetTextColor(255,0,0) +kCVi  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." fM8kS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." dIv/.x/V  
    SetTextColor(0,0,0) '>FJk`i
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    'Current directory of this script (should be the same as the text files being merged) oiAU}iK:  
    Dim cDir As String u:H@]z(x  
    cDir = MacroDir$ & "\" 6w{^S~rqo  
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    'Array which will be populated with the list of files to be merged wP3PI.g-g  
    Dim fList() As String, curFile As String Zrfp4SlZZ  
    GetFileList( cDir, fList ) g3{)AX[Uy  
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    Print "" ,-u | l  
    Print "Files found for merging:" 6suB!XF;  
    For Each curFile In fList R`=IYnoOA  
        Print Chr(9) & curFile GEP YSp  
    Next 'qLk"   
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. |7WzTz  
    Dim nameArray() As String, sampName As String J)(H-xvV  
    nameArray = Split(fList(0)," 0-0.txt") ko!38BH`/  
    sampName  = nameArray(0) S|T:rc(~  
    Print "" UNocm0!N'  
    Print "Sample name: " & Chr(9) & sampName AG)N^yd  
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    'Open an output file and write the FRED header data BX
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    Dim outFile As String q|2{W.P5qi  
    outFile = cDir & sampName & "_FRED.txt" AF D/
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    Open outFile For Output As #1 +Cx~4zEq  
    Print #1, "type bsdf_data" g=; rM8W  
    Print #1, "format angles=deg bsdf=value scale=1" mm%w0dOb"  
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    'Loop the file list, skip the two header lines and write the remaining data to file <Xw 6m$fr:  
    Dim lineArray() As String, curLine As Long *sf9(%j  
    For Each curFile In fList lj%8(Xu  
        Print "Merging data from file " & curFile R@>R@V>c  
        ReadFile( cDir & curFile, lineArray ) Faa:h#  
        For curLine = 2 To UBound(lineArray) T,(IdVlJ  
            Print #1, lineArray(curLine) Kbx(^f12  
        Next Wf_aEW&n  
    Next YU76(S9 0#  
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    'Close the output file YkPz ~;  
    Close #1 S$%/9^\jF  
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    Print "Finished merging RPC data for sample " & sampName jLvI!q   
    Print "FRED formatted data file: " & Chr(9) & outFile 8+a/x#b-  
End Sub _ %&"4bm.  
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'Utility function to read the contents of a file into an array of strings. PGT!HdX#{  
Function ReadFile(ByVal fileName As String, _ D]y6*Ha  
                  ByRef lineArray() As String) As Long bXq,iX  
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    ReadFile = -1 EN.yU!N.4  
    Dim oFSO As Object UkNC|#l)  
    Set oFSO = CreateObject("Scripting.FileSystemObject") H?40yu2m5  
    Erase lineArray hl}#bZ8]  
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    Dim fid As Long i[3$Wi$  
    If oFSO.fileexists( fileName ) Then *-+~H1tP  
        fid = FreeFile() !::k\}DS  
        Open fileName For Input As fid {KwLcSn  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) nS?HH6H  
        Close fid |BH, H  
    End If rA*,)I_v@  
    Set oFSO = Nothing l0D.7>aj  
    Return UBound( lineArray ) Z+t?ah00  
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End Function q(.%f
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Sub GetFileList( ByVal in_dir As String, _ idO3/>R [  
                 ByRef in_flist() As String ) 08k1 w,6W  
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    'Redimension the file list array m OmT]X  
    Erase in_flist }r^MXv~(  
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    'Tracks how many files are found 4Hzbb#  
    Dim fCount As Long A9l^S|r  
    fCount = 0 73}k[e7e  
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    'Recurse directory and search for text files [&3"kb  
    Dim f As String w5|@vB/pj  
    f = Dir$(in_dir & "*.txt") PYz| d  
    While f <> "" K&|zWpb  
        ReDim Preserve in_flist(fCount) w4L\@y3  
        in_flist(fCount) = f SmR*b2U  
        fCount += 1 ixKQh};5/  
        f = Dir$() 0l 3RwWj  
    Wend 3&' STPpW  
    ReDim Preserve in_flist(fCount-1) Z,iklB-  
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End Sub {{EQM +