[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： V[Auw3)  
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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。 }<A\>  
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背景： X8p-VCkV  
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。 "ifYy>d  
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。 fY$M**/,  
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步骤 yw$er?  
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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。 -+-@Yq$  
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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） t|%wVj?_  
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 !z$.Jcr1  
例如下所示： $9j\sZ
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Sample name:  EDF-C1-56 '
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Merging data from file EDF-C1-56 0-0.txt vc5g4ud  
Finished merging RPC data for sample EDF-C1-56 m "h{HgJd  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt "i(k8+iK  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 6/Q'o5>NL:  
a. 创建一个新的散射库 tc.R(F96  
b. 散射模型命名 L"P$LEk  
c. 改变散射模型为“Tabulated BSDF”. 5_x8!v  
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 ） $&I##od  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 I|@%|sTW  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， k$j>_U? P  
g. 点击OK D({%FQ"  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 @GK0j"_  
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脚本代码： R6r'[-B2  
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'#Language "WWB-COM" q okgu$2  
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Option Explicit x$tx!%,)/S  
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Sub Main @b
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    'Cleanup NiQ`,Q$B  
    ClearOutputWindow() LJt#c+]Li  
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    Print "Merging RPC Photonics BSDF Data Files" l\I#^N  
    SetTextColor(255,0,0) *BF5B\[r?  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." XXBN Nr_CK  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." =* oFs|v  
    SetTextColor(0,0,0) M{<cqxY  
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    'Current directory of this script (should be the same as the text files being merged) !`LaX!bmp  
    Dim cDir As String i<@6f'Kir  
    cDir = MacroDir$ & "\" $vlq]6V8  
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    'Array which will be populated with the list of files to be merged 8D@H4O.  
    Dim fList() As String, curFile As String /7/d u[P6  
    GetFileList( cDir, fList ) ,u8)g;8s  
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    Print "" `xMmo8u4  
    Print "Files found for merging:" Ue^2H[zs-  
    For Each curFile In fList {7.."@Ob<v  
        Print Chr(9) & curFile ?5_~Kn%2  
    Next pC2ZN  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. G0Q}
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    Dim nameArray() As String, sampName As String Vf9PHHH|   
    nameArray = Split(fList(0)," 0-0.txt") {/#^v?,  
    sampName  = nameArray(0) y!)  
    Print "" mrX 2w  
    Print "Sample name: " & Chr(9) & sampName GVhO}m  
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    'Open an output file and write the FRED header data = _X#JP79  
    Dim outFile As String KJ M:-z@  
    outFile = cDir & sampName & "_FRED.txt" F67%xz0  
    Open outFile For Output As #1 ErIAS6HS'  
    Print #1, "type bsdf_data" g`I`q3EF)  
    Print #1, "format angles=deg bsdf=value scale=1" |:BKexjHL  
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    'Loop the file list, skip the two header lines and write the remaining data to file 6bF?2 OC  
    Dim lineArray() As String, curLine As Long $N4%I4  
    For Each curFile In fList 3C'`K,
  
        Print "Merging data from file " & curFile /I&Hq7SW`  
        ReadFile( cDir & curFile, lineArray ) zO8`xrN!  
        For curLine = 2 To UBound(lineArray) ~b;l08 <  
            Print #1, lineArray(curLine) 8|*#r[x  
        Next 41Bp^R}^/  
    Next q_S`@2Dzz,  
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    'Close the output file {C3AxK0  
    Close #1 mCOJ1}  
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    Print "Finished merging RPC data for sample " & sampName ]k~Vh[[  
    Print "FRED formatted data file: " & Chr(9) & outFile HEdOo~/~  
End Sub E`s9SE  
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'Utility function to read the contents of a file into an array of strings. x}o]R  
Function ReadFile(ByVal fileName As String, _ OjO$.ecT  
                  ByRef lineArray() As String) As Long ;sJUTp5\h  
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    ReadFile = -1 ]4~- z3=y  
    Dim oFSO As Object ,Fo7E  
    Set oFSO = CreateObject("Scripting.FileSystemObject") X{KWBk.1  
    Erase lineArray =5=D)x~  
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    Dim fid As Long *%
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    If oFSO.fileexists( fileName ) Then 94C)63V  
        fid = FreeFile() *AX)QKQ@  
        Open fileName For Input As fid uX_A4ht*  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf)
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        Close fid 3S='/^l  
    End If u=^0n2ez  
    Set oFSO = Nothing Fq3[/'M^  
    Return UBound( lineArray ) #;cDPBv*wS  
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End Function 2B&Yw  
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Sub GetFileList( ByVal in_dir As String, _ ^ei[#I  
                 ByRef in_flist() As String ) DC
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    'Redimension the file list array Cr0 \7  
    Erase in_flist Z-[nHSf  
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    'Tracks how many files are found LL3RC6;e  
    Dim fCount As Long Kp,}7%hDw!  
    fCount = 0 1o)Vzv  
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    'Recurse directory and search for text files *;A I0  
    Dim f As String G"!YV#"~  
    f = Dir$(in_dir & "*.txt") -
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    While f <> "" ?m-kpW8  
        ReDim Preserve in_flist(fCount) L8-
  
        in_flist(fCount) = f [{3WHS.  
        fCount += 1 lSP{9L6  
        f = Dir$() *0bbSw1kc  
    Wend \ZrLh,6f.  
    ReDim Preserve in_flist(fCount-1) T=7V+  
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End Sub /_~b~3{u