[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： oDV6[e  
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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。 @2/|rq  
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背景： Q}|K29Y:p  
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。 N=BG0t$  
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。 LXK!4(xaW  
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步骤 YND}P9 h  
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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。 0SQr%:zG  
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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） ![\-J$  
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 %`
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例如下所示： h<U?WtWT-p  
Sample name:  EDF-C1-56 &7f8\TG|  
Merging data from file EDF-C1-56 0-0.txt o=3hWbe  
Finished merging RPC data for sample EDF-C1-56 O`9c!_lis  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt `SFeln{1B  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 >MHlrSH2  
a. 创建一个新的散射库 Bi:lC5d5?  
b. 散射模型命名 rk W7;!  
c. 改变散射模型为“Tabulated BSDF”. x%=CEe?6  
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 ） }yEV&& @  
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。 93HVx#  
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， N s+g9+<A  
g. 点击OK ki9&AFs2X  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 n"Ie>  
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脚本代码： HE,L8S  
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'#Language "WWB-COM" T+v*@#iJ_  
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Option Explicit ;>v.(0FE6  
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Sub Main |6*Bu1  
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    'Cleanup sllT1%?  
    ClearOutputWindow() WR)=VE   
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    Print "Merging RPC Photonics BSDF Data Files" 0N,<v7PX  
    SetTextColor(255,0,0) }`B .(3n  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ('5?-  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." OOqT0wN  
    SetTextColor(0,0,0) < '5~p$  
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    'Current directory of this script (should be the same as the text files being merged) dH^6K0J  
    Dim cDir As String *y*tI}  
    cDir = MacroDir$ & "\" u#@/^h;  

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    'Array which will be populated with the list of files to be merged N'v3 |g  
    Dim fList() As String, curFile As String U>E: Ub0r  
    GetFileList( cDir, fList ) 7Jf~Bn  
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    Print "" I\.|\^  
    Print "Files found for merging:" tK%ie
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    For Each curFile In fList %":3xj'EEI  
        Print Chr(9) & curFile ?G,4N<]Nu  
    Next 
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. >|QH I d8  
    Dim nameArray() As String, sampName As String Zhq_ pus"a  
    nameArray = Split(fList(0)," 0-0.txt") }`"}eN @,  
    sampName  = nameArray(0) aOzIo-  
    Print "" ,9P-<P  
    Print "Sample name: " & Chr(9) & sampName -+*h'zZ[<w  
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    'Open an output file and write the FRED header data {@InOo!4w]  
    Dim outFile As String ]@&X*~c^Z  
    outFile = cDir & sampName & "_FRED.txt" +F;2FD$  
    Open outFile For Output As #1 N[I@}j  
    Print #1, "type bsdf_data" ic2D$`M  
    Print #1, "format angles=deg bsdf=value scale=1" BsQ;`2  
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    'Loop the file list, skip the two header lines and write the remaining data to file Pd91<L  
    Dim lineArray() As String, curLine As Long g3tE.!a5-  
    For Each curFile In fList 24jf`1XFW  
        Print "Merging data from file " & curFile {D4FYr J  
        ReadFile( cDir & curFile, lineArray ) U]3!"+Y1P  
        For curLine = 2 To UBound(lineArray)  Unk/uk  
            Print #1, lineArray(curLine) X0
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        Next X1^VdJE  
    Next ^Oz~T
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    'Close the output file \O|S
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    Close #1 tdm7MPM  
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    Print "Finished merging RPC data for sample " & sampName V?{d<Ng~J  
    Print "FRED formatted data file: " & Chr(9) & outFile -b-a21,m>  
End Sub ?v2_7x&  
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'Utility function to read the contents of a file into an array of strings. yYCS-rF>  
Function ReadFile(ByVal fileName As String, _ ,!:c6F+  
                  ByRef lineArray() As String) As Long C]L)nCOBX  
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    ReadFile = -1 ;+hh|NiQ  
    Dim oFSO As Object ~apt,hl  
    Set oFSO = CreateObject("Scripting.FileSystemObject") WcN4ff-  
    Erase lineArray ,->ihxf  
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    Dim fid As Long 7[m+r:y  
    If oFSO.fileexists( fileName ) Then (?qCtLZ  
        fid = FreeFile() ;(NTzBq!1  
        Open fileName For Input As fid fCY|iO0.t  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) |;gx;qp4cN  
        Close fid '.Y,VJaL  
    End If uN%C
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    Set oFSO = Nothing x"2p5T7*>  
    Return UBound( lineArray ) K"!rj.Da  
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End Function tiK M+ ;C  
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Sub GetFileList( ByVal in_dir As String, _ Id=
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                 ByRef in_flist() As String ) )PN8HJAArh  
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    'Redimension the file list array 3qWrSziD  
    Erase in_flist %xgP*%Sv2  
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    'Tracks how many files are found =D(a~8&,  
    Dim fCount As Long v^C\ GDH  
    fCount = 0 9wL2NC31Q  
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    'Recurse directory and search for text files qCI&H7u@  
    Dim f As String RZz?_1'  
    f = Dir$(in_dir & "*.txt") !@z9n\Yj  
    While f <> "" 01n!T2;yW}  
        ReDim Preserve in_flist(fCount) !.R-|<2|6  
        in_flist(fCount) = f / 4Q=%n  
        fCount += 1 e
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        f = Dir$() DwBe_h.  
    Wend O@$>'Z  
    ReDim Preserve in_flist(fCount-1) DFr$2Y3H  
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End Sub S]H[&o1o