[分享]RPC Photonics扩散片BSDF [复制链接]

摘要： 3Y$GsN4ln  
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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。 `ERz\`d~Y;  
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背景： <a3WKw  
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。 5{,<j\#L  
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。 H Pz+Dm  
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步骤 |[8Th4*n  
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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。 $F.a><1rY  
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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） C0Z=~Q%  
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 q) KKvO  
例如下所示： JucY[`|JV  
Sample name:  EDF-C1-56 _Fg5A7or  
Merging data from file EDF-C1-56 0-0.txt aN3;`~{9  
Finished merging RPC data for sample EDF-C1-56 Aos+dP5h,8  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt owv[M6lbD  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ,V}WM%Km  
a. 创建一个新的散射库 lyhiFkO iH  
b. 散射模型命名 WNc0W>*NE1  
c. 改变散射模型为“Tabulated BSDF”. a 1*p*dM#  
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 ） oXgcc*j  
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。 6Kz,{F@  
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， uyx 2;f  
g. 点击OK [Ch.cE_  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 G3
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脚本代码： \fe]c :  
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'#Language "WWB-COM" aw>#P   
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Option Explicit &)<)^.@3G^  
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Sub Main 93hxSRw  

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    'Cleanup poFg1  
    ClearOutputWindow() -s/ea~=R  
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    Print "Merging RPC Photonics BSDF Data Files" #X"@<l4F  
    SetTextColor(255,0,0) Xn ;AZu^'R  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." kU`r)=1"  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 8dhUBJ0_  
    SetTextColor(0,0,0) .N(p=9  
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    'Current directory of this script (should be the same as the text files being merged) a'IdYW0  
    Dim cDir As String U/BR*Zn]*  
    cDir = MacroDir$ & "\" 9nbLg5P  
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    'Array which will be populated with the list of files to be merged #$y?v%^  
    Dim fList() As String, curFile As String ehY5!D1Q  
    GetFileList( cDir, fList ) vfo~27T{(  
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    Print "" 8~gLqh8^V  
    Print "Files found for merging:" A5w6]:f2  
    For Each curFile In fList 0ZO2#>gh$  
        Print Chr(9) & curFile v.5+7,4  
    Next 1-QS~)+  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. g=o4Q< #^y  
    Dim nameArray() As String, sampName As String ;9g2?-svw  
    nameArray = Split(fList(0)," 0-0.txt") >F&47Yn  
    sampName  = nameArray(0) o _H`o&xr  
    Print "" " 2Dngw  
    Print "Sample name: " & Chr(9) & sampName 0
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    'Open an output file and write the FRED header data Xn\jO>[Ef  
    Dim outFile As String
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    outFile = cDir & sampName & "_FRED.txt" jF*j0PkNdb  
    Open outFile For Output As #1 lb1Xsgm{  
    Print #1, "type bsdf_data" 1ZRT:N<-  
    Print #1, "format angles=deg bsdf=value scale=1" dC4'{n|7  
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    'Loop the file list, skip the two header lines and write the remaining data to file >-{Hyx  
    Dim lineArray() As String, curLine As Long @xZR9Z8]L  
    For Each curFile In fList /H+a0`/  
        Print "Merging data from file " & curFile PnG
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        ReadFile( cDir & curFile, lineArray ) 61 ~upQaR  
        For curLine = 2 To UBound(lineArray) n{SJ_S#a.a  
            Print #1, lineArray(curLine) 76` .Y  
        Next dAe')N:KPI  
    Next !5?<% *  
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    'Close the output file T9q-,w/j;  
    Close #1 KCDE{za  
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    Print "Finished merging RPC data for sample " & sampName lB[kbJ  
    Print "FRED formatted data file: " & Chr(9) & outFile .w,q0<}  
End Sub /|&*QLy  
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'Utility function to read the contents of a file into an array of strings. '$QB$2~V  
Function ReadFile(ByVal fileName As String, _ Oz#{S:24M+  
                  ByRef lineArray() As String) As Long wn)W ?P;k  
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    ReadFile = -1 xi;`ecqS<  
    Dim oFSO As Object HLHz2-lI  
    Set oFSO = CreateObject("Scripting.FileSystemObject") $xdy&  
    Erase lineArray _t}WsEQ+P  
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    Dim fid As Long ~.lPEA %%  
    If oFSO.fileexists( fileName ) Then vgN&K@hJ  
        fid = FreeFile() $7A8/#  
        Open fileName For Input As fid eGbG
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) m<2M4u   
        Close fid :S(ZzY Q  
    End If 5.J.RE"M  
    Set oFSO = Nothing jOD?|tK&  
    Return UBound( lineArray ) "Os_vlapHo  
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End Function yJe>JK~)  
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Sub GetFileList( ByVal in_dir As String, _ >~+ELVB&  
                 ByRef in_flist() As String ) % +\."eC  
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    'Redimension the file list array -1ub^f
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    Erase in_flist 57'4ljvYi  
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    'Tracks how many files are found IRqy%@)  
    Dim fCount As Long PRE|+=w$  
    fCount = 0 &~U ]~;@  
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    'Recurse directory and search for text files 1D!<'`)AY  
    Dim f As String ^\,E&=/}M  
    f = Dir$(in_dir & "*.txt") 2Q:+
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    While f <> "" -!]ZMi9  
        ReDim Preserve in_flist(fCount) gt w Q-  
        in_flist(fCount) = f ,UdVNA  
        fCount += 1 WQO) =n  
        f = Dir$() K8Y=S12Ti  
    Wend 2P{Gxz<#  
    ReDim Preserve in_flist(fCount-1) "|KP'<8%  
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End Sub P\)iZiGc  
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