[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 
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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。 Ggry,3X3  
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背景： %xrldn%  
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。 hg2Ywzfm-  
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。 8]mRX~  
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步骤 {)(Mkm+d  
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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。 @ZRg9M:N  
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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） 1-$+@Xl  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 Eh^gR`I  
例如下所示： EW`3$J;  
Sample name:  EDF-C1-56 R"j<C13;%  
Merging data from file EDF-C1-56 0-0.txt @/,0()*dL  
Finished merging RPC data for sample EDF-C1-56 ~ mzX1[  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt uFA}w:Fm  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 MOPHu O{^  
a. 创建一个新的散射库 %l,CJd5  
b. 散射模型命名 `A9fanh  
c. 改变散射模型为“Tabulated BSDF”. w
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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 ） *R}p9;dpO  
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。 m>|7&l_  
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， |8tKN"QG  
g. 点击OK _0BQnzC=  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 4V c``Um  
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脚本代码： k<x7\T  
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'#Language "WWB-COM" YC$>D?FW  
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Option Explicit Apj[z2nr  
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Sub Main 4V;-*:  
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    'Cleanup M N (o  
    ClearOutputWindow() na*Z0y  
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    Print "Merging RPC Photonics BSDF Data Files" 1:Ff#Eq,s  
    SetTextColor(255,0,0) v}id/brl  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." (>,b5g  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." F("|SOhc  
    SetTextColor(0,0,0) M2;6Cz>,P  
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    'Current directory of this script (should be the same as the text files being merged) n1aOpz6`  
    Dim cDir As String 2a;[2':  
    cDir = MacroDir$ & "\" Z?d][zGw  
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    'Array which will be populated with the list of files to be merged `4?|yp.|L  
    Dim fList() As String, curFile As String !x\\# 9  
    GetFileList( cDir, fList ) =**Q\Sl  
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    Print "" :Gzp (@<@e  
    Print "Files found for merging:" Jz*A!Li  
    For Each curFile In fList _0ZU I^#  
        Print Chr(9) & curFile =Ot_P7'5gv  
    Next acgx')!c  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 'vYt_T  
    Dim nameArray() As String, sampName As String q: X^V$`  
    nameArray = Split(fList(0)," 0-0.txt") sCmN|Q  
    sampName  = nameArray(0) \/C5L:|p_  
    Print "" U(Bmffn4Z  
    Print "Sample name: " & Chr(9) & sampName dt>9mF q  
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    'Open an output file and write the FRED header data ;@:-T/=  
    Dim outFile As String o\PHs4Ws'7  
    outFile = cDir & sampName & "_FRED.txt" rg=Ym.  
    Open outFile For Output As #1 Ck>]+rl  
    Print #1, "type bsdf_data" ;.rY`<|  
    Print #1, "format angles=deg bsdf=value scale=1" ]>ndFE6kl  
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    'Loop the file list, skip the two header lines and write the remaining data to file %mD{rG9  
    Dim lineArray() As String, curLine As Long 5iI(A'R[7  
    For Each curFile In fList lA;qFXaN>  
        Print "Merging data from file " & curFile V6h8+|hK  
        ReadFile( cDir & curFile, lineArray ) 6__HqBQ  
        For curLine = 2 To UBound(lineArray) L "'d(MD  
            Print #1, lineArray(curLine) V#+F*w?&D  
        Next US"UkY-\  
    Next \zwm:@lG  
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    'Close the output file g$vOWSI+  
    Close #1 0LSJQ9\p  
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    Print "Finished merging RPC data for sample " & sampName ImD&~^-_<  
    Print "FRED formatted data file: " & Chr(9) & outFile [wnaF|h  
End Sub 8J
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'Utility function to read the contents of a file into an array of strings. M;NIcM  
Function ReadFile(ByVal fileName As String, _ yq<W+b/  
                  ByRef lineArray() As String) As Long #/8 Nav  
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    ReadFile = -1 $9xp@8b\_  
    Dim oFSO As Object baL<|& c  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ZG{#CC
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    Erase lineArray WS?Y8~+{5  
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    Dim fid As Long 4Ssy (gt  
    If oFSO.fileexists( fileName ) Then rz2,42H]  
        fid = FreeFile()
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        Open fileName For Input As fid t<$J 3h/"  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) :#{0yno)H  
        Close fid dTlEEgR  
    End If Kb-m  
    Set oFSO = Nothing _34%St!lg  
    Return UBound( lineArray ) GU9p'E  
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End Function oIMS >&  
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Sub GetFileList( ByVal in_dir As String, _ tA'5ufj*:  
                 ByRef in_flist() As String ) -^;,m=4{3  
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    'Redimension the file list array a<>cbP  
    Erase in_flist wlslG^^(!  
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    'Tracks how many files are found %K7;ePu  
    Dim fCount As Long Nez '1  
    fCount = 0 :_nGh]%  
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    'Recurse directory and search for text files qV,x)y:V  
    Dim f As String %da-/[  
    f = Dir$(in_dir & "*.txt") Y?zo")  
    While f <> "" l8_RA  
        ReDim Preserve in_flist(fCount) _\= /~>Xl  
        in_flist(fCount) = f II[-6\d!  
        fCount += 1 /11CC \  
        f = Dir$() ^P A|RFP  
    Wend {a9.0N:4  
    ReDim Preserve in_flist(fCount-1) +^J;ic  
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End Sub 4!-R&<TLve