[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： </h^%mnd  
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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。 8H!QekQZ]\  
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背景： ]?Ef0?44  
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。 oo5=5s6 3}  
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。 j|eA*UE  
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步骤 K@D\5s|1|  
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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。 0I&k_7_  
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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） * QgKo$IF  
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 Uzu6>yT  
例如下所示： <wH+\  
Sample name:  EDF-C1-56 >| R'dF}  
Merging data from file EDF-C1-56 0-0.txt }cKB)N BJb  
Finished merging RPC data for sample EDF-C1-56 ?^}30V:E  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt U.%Kt,qB  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 "t@p9>  
a. 创建一个新的散射库 c'2d+*[  
b. 散射模型命名 K2   
c. 改变散射模型为“Tabulated BSDF”. i|YS>Pw~j  
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 ） v9*m0|T0M  
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。 &p0e)o~Ux  
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， UO/sv2CN  
g. 点击OK VtreOJ+  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 je4l3Hl  
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脚本代码： okNo-\Dh!  
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'#Language "WWB-COM" -N *L1Zj  
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Option Explicit $vO&C6m$  
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Sub Main QrZ#<{,J5  
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    'Cleanup n
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    ClearOutputWindow() ~Bd=]a$mj  
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    Print "Merging RPC Photonics BSDF Data Files" k9|5TLXq?  
    SetTextColor(255,0,0) cNs'GfD}  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." G dgL}"*F  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." .R9Z$Kbq  
    SetTextColor(0,0,0) U, 6iT  
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    'Current directory of this script (should be the same as the text files being merged) p{FI_6db  
    Dim cDir As String KWTV!Wxb=K  
    cDir = MacroDir$ & "\" @[$_cGR7  
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    'Array which will be populated with the list of files to be merged
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    Dim fList() As String, curFile As String V7ph^^sC}  
    GetFileList( cDir, fList ) Uv^\[   
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    Print "" NE995;  
    Print "Files found for merging:" <N<Q9}`V  
    For Each curFile In fList hy;VvAH5  
        Print Chr(9) & curFile  ao(T81  
    Next _GOSqu!3Y  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. |s|}u`(@9  
    Dim nameArray() As String, sampName As String X1L@ G  
    nameArray = Split(fList(0)," 0-0.txt") ~z,o):q1}  
    sampName  = nameArray(0) 8HF^^Cva  
    Print "" _n&Nw7d2 M  
    Print "Sample name: " & Chr(9) & sampName 3} A$+PX  
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    'Open an output file and write the FRED header data ?RRO  
    Dim outFile As String :Pud%}'  
    outFile = cDir & sampName & "_FRED.txt" PnsBDf%v  
    Open outFile For Output As #1 @@EI=\  
    Print #1, "type bsdf_data" >rnVTK  
    Print #1, "format angles=deg bsdf=value scale=1" 74s{b]jN'-  
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    'Loop the file list, skip the two header lines and write the remaining data to file FLZ9pb[T  
    Dim lineArray() As String, curLine As Long \& JZ >h  
    For Each curFile In fList AeJ

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        Print "Merging data from file " & curFile _k-_&PR  
        ReadFile( cDir & curFile, lineArray ) xNz(LZ.c  
        For curLine = 2 To UBound(lineArray) W,q @ww u  
            Print #1, lineArray(curLine) pwUXM?$R  
        Next LQ0/oYmNc  
    Next #6sz@XfV  
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    'Close the output file K}*ets1s}  
    Close #1 .nV2n@SR  
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    Print "Finished merging RPC data for sample " & sampName oy+|:[v:Fk  
    Print "FRED formatted data file: " & Chr(9) & outFile |d
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End Sub {C1crp>q  
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'Utility function to read the contents of a file into an array of strings. OLw]BJXYaE  
Function ReadFile(ByVal fileName As String, _ e3~MU6  
                  ByRef lineArray() As String) As Long ^:nc'C gP  
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    ReadFile = -1 *4,Q9K_  
    Dim oFSO As Object R!nf^*~  
    Set oFSO = CreateObject("Scripting.FileSystemObject") A|A~$v("R  
    Erase lineArray jnH\}IB  
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    Dim fid As Long %idBR7?`g  
    If oFSO.fileexists( fileName ) Then >A#5` $i  
        fid = FreeFile()
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        Open fileName For Input As fid p6M9uu  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) cx}Yu8  
        Close fid [g}Cve#i  
    End If MqmQ52HR  
    Set oFSO = Nothing Ik G&  
    Return UBound( lineArray )  ZR.k'  
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End Function Mk!Fy]3  
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Sub GetFileList( ByVal in_dir As String, _ rb?7i&-  
                 ByRef in_flist() As String ) R|;BO:S1  
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    'Redimension the file list array .35(MFvq!  
    Erase in_flist nep#L>LP$x  
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    'Tracks how many files are found "k
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    Dim fCount As Long XcR=4q|7  
    fCount = 0 6Yai?*.Q
 
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    'Recurse directory and search for text files 'u
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    Dim f As String D:P(;  
    f = Dir$(in_dir & "*.txt") hC
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    While f <> "" *yq65yZi5  
        ReDim Preserve in_flist(fCount) RQ+,7Ir  
        in_flist(fCount) = f (qn=BPI  
        fCount += 1 CTMC78=9}  
        f = Dir$() G|i0n   
    Wend yi7.9/;a  
    ReDim Preserve in_flist(fCount-1) h*w9{[L  
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End Sub 6v%yU3l