[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： m.D8@[y  
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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。 MG?,,8sO  
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背景： ^yW['H6V  
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。 \Oq2{Sx\
 
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。 /EjXyrn2  
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步骤 pX&bX_F{  
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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。 Ta\F~$M  
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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） ~vXbh(MX  
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 f1vD{M;  
例如下所示： F\eQV<  
Sample name:  EDF-C1-56 }u;K<<h:  
Merging data from file EDF-C1-56 0-0.txt Jl_W6gY"Z  
Finished merging RPC data for sample EDF-C1-56 Z5t^D|  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 0OO[@Ht  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 t=B1yvE"  
a. 创建一个新的散射库 v~>Bbe  
b. 散射模型命名 F^GNOD3J  
c. 改变散射模型为“Tabulated BSDF”. P*KIk~J  
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 ） Lg<h54X  
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。 7(}'
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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， /4T
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g. 点击OK '~Y@HRVL@|  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 /ZyMD(_J  
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脚本代码： u\ _yjv#  
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'#Language "WWB-COM" X):7#x@uy  
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Option Explicit Hs)Cf)8u  
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Sub Main X,
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    'Cleanup P")I)>Q6  
    ClearOutputWindow() ,ayEZ#4.m  
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    Print "Merging RPC Photonics BSDF Data Files" <|l}@\iRX  
    SetTextColor(255,0,0) W
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    Print "Note: Script should be located in the same folder as the BSDF TXT files." z% bH?1^o  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." jfG of*  
    SetTextColor(0,0,0) JOuyEPy  
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    'Current directory of this script (should be the same as the text files being merged) Xqw}O2QQ1  
    Dim cDir As String _^W;J/He  
    cDir = MacroDir$ & "\" JlYZ\  
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    'Array which will be populated with the list of files to be merged B>nj{W<o  
    Dim fList() As String, curFile As String 6FzB-],  
    GetFileList( cDir, fList ) [2-n*a(q  
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    Print "" ?Kgb-bXB  
    Print "Files found for merging:" lWY
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    For Each curFile In fList :|n[zjK/S  
        Print Chr(9) & curFile 'S3<' X  
    Next LWCFCkx%  

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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. S L 5k^|  
    Dim nameArray() As String, sampName As String Zp)=l Td  
    nameArray = Split(fList(0)," 0-0.txt") s|WwB
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    sampName  = nameArray(0) Dnd; N/9  
    Print "" ]L~NYe9  
    Print "Sample name: " & Chr(9) & sampName (T*$4KGV  
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    'Open an output file and write the FRED header data O2>c|=#  
    Dim outFile As String u{DEOhtI4  
    outFile = cDir & sampName & "_FRED.txt" d1/WUKmbZ  
    Open outFile For Output As #1 MS\vrq'_  
    Print #1, "type bsdf_data" y.lWyH9  
    Print #1, "format angles=deg bsdf=value scale=1" {A/^;
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    'Loop the file list, skip the two header lines and write the remaining data to file
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    Dim lineArray() As String, curLine As Long zx%WV@O9  
    For Each curFile In fList ['o ueOg  
        Print "Merging data from file " & curFile Mw0>p5+ cy  
        ReadFile( cDir & curFile, lineArray ) yD~,+
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        For curLine = 2 To UBound(lineArray) 4fsd5#  
            Print #1, lineArray(curLine) ketp9}u  
        Next _CH
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    Next 3q
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    'Close the output file 3'.@aMA@  
    Close #1 l^&#9d  
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    Print "Finished merging RPC data for sample " & sampName o{y}c->  
    Print "FRED formatted data file: " & Chr(9) & outFile K ~mUO  
End Sub jae9!Wi  
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'Utility function to read the contents of a file into an array of strings. -g~+9/;n  
Function ReadFile(ByVal fileName As String, _ ^i%S}VK  
                  ByRef lineArray() As String) As Long gbuh04#~  
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    ReadFile = -1 h&i*=&<HP6  
    Dim oFSO As Object 1*=ev,Z  
    Set oFSO = CreateObject("Scripting.FileSystemObject") sm-[=d%@L  
    Erase lineArray JVuju$k  
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    Dim fid As Long M?lh1Yu"  
    If oFSO.fileexists( fileName ) Then H<Sf0>OA  
        fid = FreeFile() `sKyvPtG  
        Open fileName For Input As fid M,fL(b;2  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Oin9lg-jR  
        Close fid =3
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    End If :$"{-n  
    Set oFSO = Nothing I&+.IK_  
    Return UBound( lineArray ) JjS+'A$A5  
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End Function 1*8;)#%&  
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Sub GetFileList( ByVal in_dir As String, _ ~W21%T+  
                 ByRef in_flist() As String ) hty'L61\z  
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    'Redimension the file list array `0NU c)`  
    Erase in_flist (S!UnBb&  
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    'Tracks how many files are found (%fQhQ  
    Dim fCount As Long ~Y/A]N86,  
    fCount = 0 geR :FO;\  
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    'Recurse directory and search for text files ;}+M2Ec51  
    Dim f As String ,LA'^I?  
    f = Dir$(in_dir & "*.txt") (C. $w  
    While f <> "" y5sH7`2+5  
        ReDim Preserve in_flist(fCount) 2G~{x7/[@  
        in_flist(fCount) = f D;!sH?J@+  
        fCount += 1 2uEI@B  
        f = Dir$() /f[Ek5/-0  
    Wend >B{qPrmI  
    ReDim Preserve in_flist(fCount-1) XKTDBaON  
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End Sub U(f@zGV