[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： CEwG#fZ  
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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。 3]wV`mD  
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背景： 6,k}v:  
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。 3o6N&bQ b  
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。 MVV<&jho{^  
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步骤 MLUq"f~N  
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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{N#^L!  
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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） GeE|&popO  
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 4rv3D@E  
例如下所示： _,5(HETE2  
Sample name:  EDF-C1-56 t0/fF'GZD  
Merging data from file EDF-C1-56 0-0.txt .x}ImI  
Finished merging RPC data for sample EDF-C1-56 ^}9Aq $R  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt N1_nBQF )  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 9v^MZ^Y{  
a. 创建一个新的散射库 NX$$4<A1  
b. 散射模型命名 ~W!sxM5(*  
c. 改变散射模型为“Tabulated BSDF”. #qHo+M$"  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） UAa2oY&  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 ceAK;v o  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， >pr{)bp G  
g. 点击OK [&6l=a  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 IS"UBJ6p  
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脚本代码： (eHvp  
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'#Language "WWB-COM" s(F^P  
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Option Explicit 5WY..60K,  
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Sub Main JQ!D8Ut  
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    'Cleanup R:zjEhH)  
    ClearOutputWindow() Q']:k}y  
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    Print "Merging RPC Photonics BSDF Data Files" OE WIP  
    SetTextColor(255,0,0) 5{VrzzOK}  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." {}[S,L  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ^2XoYgv  
    SetTextColor(0,0,0) ,:j^EDCsaJ  
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    'Current directory of this script (should be the same as the text files being merged) DtR-NzjB  
    Dim cDir As String 's+ Fd~'  
    cDir = MacroDir$ & "\" :U^a0s%B  
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    'Array which will be populated with the list of files to be merged ~%m-}Sxc  
    Dim fList() As String, curFile As String RR*<txdN  
    GetFileList( cDir, fList )  jmz, 1[  

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    Print "" ZI-)'  
    Print "Files found for merging:" P8piXG  
    For Each curFile In fList OiZPL"Q(K  
        Print Chr(9) & curFile j'I$F1>Te  
    Next c"v#d9  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ZoF\1C ^  
    Dim nameArray() As String, sampName As String =&< s*-l[  
    nameArray = Split(fList(0)," 0-0.txt") i` n,{{x&4  
    sampName  = nameArray(0) iE0A-;:5  
    Print "" [?yOJU%`  
    Print "Sample name: " & Chr(9) & sampName #Q"el3P+q  
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    'Open an output file and write the FRED header data /!uxP~2U  
    Dim outFile As String lmgMR|v  
    outFile = cDir & sampName & "_FRED.txt" _\1wLcFj  
    Open outFile For Output As #1 JIQS'
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    Print #1, "type bsdf_data" ;N6L`|  
    Print #1, "format angles=deg bsdf=value scale=1" 1Hp0,R}  
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    'Loop the file list, skip the two header lines and write the remaining data to file 5a&[NN  
    Dim lineArray() As String, curLine As Long ]@)X3}"!  
    For Each curFile In fList `[2nxP>w`  
        Print "Merging data from file " & curFile pg;agtI  
        ReadFile( cDir & curFile, lineArray ) g< M\zD  
        For curLine = 2 To UBound(lineArray) 4hr;k0sD  
            Print #1, lineArray(curLine) Q_x/e|sd  
        Next OXK?R\ E+  
    Next z+C>P4c-y&  
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    'Close the output file 80x %wCY`  
    Close #1 % Lhpj[C  
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    Print "Finished merging RPC data for sample " & sampName 1.4]T, `  
    Print "FRED formatted data file: " & Chr(9) & outFile !FX;QD@"  
End Sub <}L`d(E@f  
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'Utility function to read the contents of a file into an array of strings. x@;XyQq  
Function ReadFile(ByVal fileName As String, _ =hH>]$J[  
                  ByRef lineArray() As String) As Long y4tM0h  
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    ReadFile = -1 Hl8-1M$&  
    Dim oFSO As Object b54<1\&  
    Set oFSO = CreateObject("Scripting.FileSystemObject") n{6XtIoYq  
    Erase lineArray s*>s;S?{|  
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    Dim fid As Long [-x~Q[  
    If oFSO.fileexists( fileName ) Then P>+{}c}3I  
        fid = FreeFile() be|k"s|6)  
        Open fileName For Input As fid ~*GJO74  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) !k)}p_e  
        Close fid BuCU_/H  
    End If rbHrG<+7zO  
    Set oFSO = Nothing vRpMZ)e  
    Return UBound( lineArray ) I3uaEv7OZc  
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End Function Z,M?!vK  
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Sub GetFileList( ByVal in_dir As String, _ '>^+_|2  
                 ByRef in_flist() As String ) sU^2I v\%  
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    'Redimension the file list array hPE#l?H@A  
    Erase in_flist Ok/~E  
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    'Tracks how many files are found >Vy=5)/i  
    Dim fCount As Long )mz [2Sfg  
    fCount = 0 b8P/9D7K?  
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    'Recurse directory and search for text files T;XEU%:LK  
    Dim f As String bHH{bv~Z  
    f = Dir$(in_dir & "*.txt") .h~M&d!  
    While f <> "" ,%w_E[2  
        ReDim Preserve in_flist(fCount) 1&\_|2  
        in_flist(fCount) = f }QU9+<Z[r  
        fCount += 1 nyWA(%N1  
        f = Dir$() %6j|/|#]  
    Wend odMjxWY  
    ReDim Preserve in_flist(fCount-1) &W:Wv,3
 
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End Sub VO] Jvf