[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： BF(Kaf;<t.  
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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。 m8z414o  
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背景： ]3~X!(
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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。 ($s%B  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 2VgVn,c  
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步骤 j?s+#t  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 J85Kgd1 \a  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） F!&_  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集  4d )Q  
例如下所示： RLUH[[  
Sample name:  EDF-C1-56 =d1R9O  
Merging data from file EDF-C1-56 0-0.txt i`vgD<}  
Finished merging RPC data for sample EDF-C1-56 AGgL`sP  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt S0mF%"  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 )!C|DSw  
a. 创建一个新的散射库 #)28ESj  
b. 散射模型命名 %|gj46  
c. 改变散射模型为“Tabulated BSDF”. Iw;J7[hJ&$  
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 ） Xd@x(T~'X  
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)ftj%  
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， qh~S)^zFJ  
g. 点击OK tC'@yX  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 w\Bx=a>vc  
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脚本代码： ]5hGSl2  
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'#Language "WWB-COM" * 57y.](w  
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Option Explicit 8CN0Q&|  
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Sub Main 1 Ll<^P  
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    'Cleanup *q+z5G;O  
    ClearOutputWindow() \`,,r_tO  
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    Print "Merging RPC Photonics BSDF Data Files" oB]  
    SetTextColor(255,0,0) *WX,bN6Ot  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." B:QAG  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." H:&|q+K=#  
    SetTextColor(0,0,0) $ h<l  
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    'Current directory of this script (should be the same as the text files being merged) V;t8v\  
    Dim cDir As String %$.]g  
    cDir = MacroDir$ & "\" @Zd/>'  
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    'Array which will be populated with the list of files to be merged ]@UJ 8hDy  
    Dim fList() As String, curFile As String tr$~INe  
    GetFileList( cDir, fList ) 84$#!=v  
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    Print "" l~9P4 ,  
    Print "Files found for merging:" 7Yrp#u1!  
    For Each curFile In fList 3gzcpFNqX  
        Print Chr(9) & curFile d)X6x-(  
    Next p 6FPdt)  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ]$gBX=  
    Dim nameArray() As String, sampName As String Sxw%6Va]p  
    nameArray = Split(fList(0)," 0-0.txt") 4,pSC  
    sampName  = nameArray(0) T2V# fYCc  
    Print "" xX]92Q  
    Print "Sample name: " & Chr(9) & sampName s=xJcLA  
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    'Open an output file and write the FRED header data (o5+9'y"9  
    Dim outFile As String U~e^  
    outFile = cDir & sampName & "_FRED.txt" ,awp)@VG7  
    Open outFile For Output As #1 ;\5^yDv[e  
    Print #1, "type bsdf_data" 0aS&!"o!  
    Print #1, "format angles=deg bsdf=value scale=1" `]xot8  
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    'Loop the file list, skip the two header lines and write the remaining data to file &J~%Nt  
    Dim lineArray() As String, curLine As Long :jp4 !0w  
    For Each curFile In fList M!ra3Y  
        Print "Merging data from file " & curFile iqj ZC80  
        ReadFile( cDir & curFile, lineArray ) _4VS.~}/R  
        For curLine = 2 To UBound(lineArray) @94_'i7\  
            Print #1, lineArray(curLine) 0Tm"Zh?B|  
        Next u*NU MT2  
    Next 5Se S^kJC  
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    'Close the output file oqOXRUy  
    Close #1 8I'Am"bc\  
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    Print "Finished merging RPC data for sample " & sampName dU~DlaEy(  
    Print "FRED formatted data file: " & Chr(9) & outFile mf>cv2+  
End Sub MFyMo  
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'Utility function to read the contents of a file into an array of strings. _\P9~w `  
Function ReadFile(ByVal fileName As String, _ p2UZqq2  
                  ByRef lineArray() As String) As Long |H)WJ/`  
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    ReadFile = -1 !%x=o&  
    Dim oFSO As Object cO#e AQf7  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ]eJjffx  
    Erase lineArray Z-!W#   
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    Dim fid As Long 3ee?B~Tun  
    If oFSO.fileexists( fileName ) Then I oz rZ  
        fid = FreeFile() o9:GKc  
        Open fileName For Input As fid xCd9b:jG  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) +C{ %pF  
        Close fid l|[8'*]r!  
    End If #egP*{F   
    Set oFSO = Nothing c !ybz{L  
    Return UBound( lineArray ) 7x%0^~/n  
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End Function "KY9MBzPD  
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Sub GetFileList( ByVal in_dir As String, _ >o\[?QvP  
                 ByRef in_flist() As String ) .g7ebh6D  
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    'Redimension the file list array =%:mZ@x'
 
    Erase in_flist .>-`2B*/  
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    'Tracks how many files are found ms8PFu(f  
    Dim fCount As Long NC 0H5  
    fCount = 0
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    'Recurse directory and search for text files b|c?xHF}K  
    Dim f As String 89B1\ff  
    f = Dir$(in_dir & "*.txt") &/7AW(?  
    While f <> "" N~-N Q  
        ReDim Preserve in_flist(fCount) f
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        in_flist(fCount) = f Cm;WQuv@  
        fCount += 1 rs@,<DV)u  
        f = Dir$() a4 g~'^uC  
    Wend n8zh;vuJ  
    ReDim Preserve in_flist(fCount-1) &Jj^)GBU  
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End Sub %}G:R!4 d