[分享]RPC Photonics扩散片BSDF [复制链接]

摘要： wn>?r ?KIB  
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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。 K1|xatx1V  
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背景： >~* w  
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。 I#:4H2H6  
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。 ,a@jg&Mb]  
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步骤 MryY<s  
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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。 FP h1}qS  
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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） <.c#l':  
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 GPU,.s"&(  
例如下所示： y/6%'56u
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Sample name:  EDF-C1-56  ood,k{  
Merging data from file EDF-C1-56 0-0.txt b#{[Pk,w9  
Finished merging RPC data for sample EDF-C1-56 Q$=X ?{  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt -x0u}I  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 aiwKkf`\  
a. 创建一个新的散射库 L3^+`e  
b. 散射模型命名 @xPWR=Lb  
c. 改变散射模型为“Tabulated BSDF”. HF]|>1WV[  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 
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e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 ^q)s  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， V.kRV{43  
g. 点击OK o"e]9{+<  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 _(J/$D  
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脚本代码： +OX:T) 4h6  
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'#Language "WWB-COM" u(g0Ob  
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Option Explicit _|vY)4B4U  
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Sub Main n0%]dKCB  
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    'Cleanup )l"py9
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    ClearOutputWindow() w>Y!5RnO  
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    Print "Merging RPC Photonics BSDF Data Files" A1V^Gi@i  
    SetTextColor(255,0,0) }2~$"L,_  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ]Geg;[t  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." FJ(}@U}57  
    SetTextColor(0,0,0) k_hs g6Ur.  
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    'Current directory of this script (should be the same as the text files being merged) U%E364;F  
    Dim cDir As String YVS~|4hu?i  
    cDir = MacroDir$ & "\" Ym5ji$!2  
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    'Array which will be populated with the list of files to be merged }D\i1/Y  
    Dim fList() As String, curFile As String Bi$nYV)-l  
    GetFileList( cDir, fList ) 55#s/`gd)^  
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    Print "" T?V!%AqY:  
    Print "Files found for merging:" Rt2<F-gY  
    For Each curFile In fList "`&1"*  
        Print Chr(9) & curFile :o+&>z  
    Next @fO[{V  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. U>=& 2Z2?  
    Dim nameArray() As String, sampName As String F>/"If#  
    nameArray = Split(fList(0)," 0-0.txt") lD\v
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    sampName  = nameArray(0) ud,=O Xq  
    Print "" EX9os  
    Print "Sample name: " & Chr(9) & sampName 0s'H(qE,_  
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    'Open an output file and write the FRED header data /7[X_)OG  
    Dim outFile As String 5T- N\)@  
    outFile = cDir & sampName & "_FRED.txt" hk.Zn.6A'  
    Open outFile For Output As #1 &yN/AY
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    Print #1, "type bsdf_data" -N~eb^3[c  
    Print #1, "format angles=deg bsdf=value scale=1" 95%QF;h  
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    'Loop the file list, skip the two header lines and write the remaining data to file 8ZPjzN>c6  
    Dim lineArray() As String, curLine As Long ;;? Zd  
    For Each curFile In fList G~N$bF^R)  
        Print "Merging data from file " & curFile 1DT}_0{0Q  
        ReadFile( cDir & curFile, lineArray ) =!{ E!3>*D  
        For curLine = 2 To UBound(lineArray) |VxO ,[~  
            Print #1, lineArray(curLine) 9qXKHro
 
        Next LOf)D7T  
    Next (D1$&  
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    'Close the output file NT&skrzW  
    Close #1 %e|.a)78  
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    Print "Finished merging RPC data for sample " & sampName dD.;P=AP  
    Print "FRED formatted data file: " & Chr(9) & outFile aq-R#q  
End Sub g\q*,1  
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'Utility function to read the contents of a file into an array of strings. Lx#CFrLQ*  
Function ReadFile(ByVal fileName As String, _ T(2*P5%&  
                  ByRef lineArray() As String) As Long '&42E[0P  
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    ReadFile = -1 #9FY;~  
    Dim oFSO As Object 7ts`uI<E@7  
    Set oFSO = CreateObject("Scripting.FileSystemObject") Kdr7JQYzuz  
    Erase lineArray wi$,Y.:  
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    Dim fid As Long W34_@,GD  
    If oFSO.fileexists( fileName ) Then `_Fxb@"R  
        fid = FreeFile() h}SP`  
        Open fileName For Input As fid x}B_;&>&"_  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) MQvk& AX  
        Close fid uXkc07 r'  
    End If nXFPoR)T  
    Set oFSO = Nothing a7YzX5n  
    Return UBound( lineArray ) 6<qVeO&uZ  
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End Function 5vo5t0^o  
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Sub GetFileList( ByVal in_dir As String, _ `m7w%J.>n  
                 ByRef in_flist() As String ) )g ; !IL  
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    'Redimension the file list array i4s_:
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    Erase in_flist Is1(]^EE*  
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    'Tracks how many files are found SQ0?M\D7  
    Dim fCount As Long EPu-oE=HW4  
    fCount = 0 7+;$_,Xo<  
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    'Recurse directory and search for text files K2 b\9}  
    Dim f As String xixdv{M<FF  
    f = Dir$(in_dir & "*.txt") )
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    While f <> "" 3[;fO_R  
        ReDim Preserve in_flist(fCount) Kd;Iu\4hv  
        in_flist(fCount) = f yhG%@vSq  
        fCount += 1 ]21`x  
        f = Dir$() lV M)'m  
    Wend VAnP3:  
    ReDim Preserve in_flist(fCount-1) ^sqTgrG  
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End Sub unD.t  
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