[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： J6[V7R[\  
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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。 K!,T.qA&=  
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背景： srCpgs]h  
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。 2if7|o$=  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 _@5|r|P>  
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步骤 9,wD  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 K2> CR$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） 4OaU1Y[  
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 hGy[L3{  
例如下所示： T!7B0_  
Sample name:  EDF-C1-56 `+m:@0&L  
Merging data from file EDF-C1-56 0-0.txt vR3\E"Zi  
Finished merging RPC data for sample EDF-C1-56 "qrde4O  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt ve]hE}o/}  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Xwo%DZKN  
a. 创建一个新的散射库 awv$ }EFo  
b. 散射模型命名 w7@TM%nS  
c. 改变散射模型为“Tabulated BSDF”. KTq+JT
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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 ） er8T:.Py  
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。 l+a1`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， \i'Z(1  
g. 点击OK X- ZZLl#  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ^6On^k[|fw  
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脚本代码： GXp`yK9c  
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'#Language "WWB-COM" 7 x'2  
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Option Explicit /go|r '  
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Sub Main eaAGlEW6J  
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    'Cleanup Nq%ir8hE  
    ClearOutputWindow() ;1HzY\d%<  
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    Print "Merging RPC Photonics BSDF Data Files" H$+@O-  
    SetTextColor(255,0,0) 4*ZY#7h  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." Sv_Nb>  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 4[(NxXH8M  
    SetTextColor(0,0,0) _U_O0@xi  
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    'Current directory of this script (should be the same as the text files being merged) ^Z-oO#)h#  
    Dim cDir As String 9Pb6Z}
 
    cDir = MacroDir$ & "\" p$t
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    'Array which will be populated with the list of files to be merged gBky
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    Dim fList() As String, curFile As String $g^D1zkuDT  
    GetFileList( cDir, fList ) RA!q)/+  
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    Print "" OXm`n/64+  
    Print "Files found for merging:" ua)jGif  
    For Each curFile In fList jU $G<G  
        Print Chr(9) & curFile
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    Next 0k#7LubWZl  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ae2Q^yLA  
    Dim nameArray() As String, sampName As String $~S~pvT  
    nameArray = Split(fList(0)," 0-0.txt") 64mg:ed&  
    sampName  = nameArray(0) f4 qVUU  
    Print "" pCDN9*0/  
    Print "Sample name: " & Chr(9) & sampName >.6|\{*sG  
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    'Open an output file and write the FRED header data j*5IRzK1%0  
    Dim outFile As String c"v75lW-J  
    outFile = cDir & sampName & "_FRED.txt" l>MDCqV  
    Open outFile For Output As #1 {#ynN`tLyF  
    Print #1, "type bsdf_data" >{N}UNZ$}  
    Print #1, "format angles=deg bsdf=value scale=1" FpiTQC7d  
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    'Loop the file list, skip the two header lines and write the remaining data to file @AF<Xp{  
    Dim lineArray() As String, curLine As Long \nt~K}a  
    For Each curFile In fList Z,/K$;YWo  
        Print "Merging data from file " & curFile ~ney~Pz_  
        ReadFile( cDir & curFile, lineArray ) d\ 8v VZ  
        For curLine = 2 To UBound(lineArray) &iInru3  
            Print #1, lineArray(curLine) #R{>@]x`  
        Next 59O-"Sc[  
    Next puJB&u"4L  
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    'Close the output file ?+))J~@t  
    Close #1 `0N7Gc  
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    Print "Finished merging RPC data for sample " & sampName bx(@ fl:m  
    Print "FRED formatted data file: " & Chr(9) & outFile m/1FVC@*  
End Sub G.H8 ><%  
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'Utility function to read the contents of a file into an array of strings. yo=L1;H  
Function ReadFile(ByVal fileName As String, _ N(Ru/9!y"  
                  ByRef lineArray() As String) As Long %\v8FCb  
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    ReadFile = -1 W;'fAohr  
    Dim oFSO As Object 54CJ6"q  
    Set oFSO = CreateObject("Scripting.FileSystemObject") W|7|XO  
    Erase lineArray
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    Dim fid As Long V6X )L>!xx  
    If oFSO.fileexists( fileName ) Then RbX9PF"|+  
        fid = FreeFile() ,\s`T O  
        Open fileName For Input As fid B=!!R]dxA  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) *qwN9b/!  
        Close fid >I|8yqbfm  
    End If ?1D!%jfi  
    Set oFSO = Nothing wX0D^)NtF  
    Return UBound( lineArray ) r*+~(
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End Function tL$,]I$1+  
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Sub GetFileList( ByVal in_dir As String, _ ? `p/jA  
                 ByRef in_flist() As String ) *O :JECKU  
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    'Redimension the file list array UDh\%?j  
    Erase in_flist =mO5~~"W+v  
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    'Tracks how many files are found KClkPL!jP  
    Dim fCount As Long az F!V  
    fCount = 0
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    'Recurse directory and search for text files +6#$6hG  
    Dim f As String zr/v.$<  
    f = Dir$(in_dir & "*.txt") i%-yR DIX  
    While f <> "" kk /#&b2  
        ReDim Preserve in_flist(fCount) w.q`E@ T*  
        in_flist(fCount) = f xoKK{&J  
        fCount += 1 d}\]!x3t  
        f = Dir$() uu.X>agg  
    Wend l8FJ\5'M  
    ReDim Preserve in_flist(fCount-1) ]E-/}Ysz  
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End Sub )8A.Wg4S;c