[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： a-hGpYJJG  
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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。 i`spM<iR.  
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背景： |}Lgo"cTC  
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。 ,_-*/- 7;8  
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。 _QCI<|A  
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步骤 r $2   
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） &d;$k  
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 a^,RbV/  
例如下所示： M] *pBc(o0  
Sample name:  EDF-C1-56 TR20{8"  
Merging data from file EDF-C1-56 0-0.txt ?Ea"%z*c5  
Finished merging RPC data for sample EDF-C1-56 g{(nt5|^l  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt n-Y'LK40Os  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 `7ZJB$7D|*  
a. 创建一个新的散射库 %W+Fe,]  
b. 散射模型命名 '_Oprx  
c. 改变散射模型为“Tabulated BSDF”. /L^dHI]Q  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 9\2&6H  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 mAa]Et.  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， V|`|CVFo
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g. 点击OK z`SkKn0f Y  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 BD+?Ad?  
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脚本代码： ^Quy64M  
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'#Language "WWB-COM" D$;/ l}s?  
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Option Explicit kvn6 NiU  
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Sub Main (0S7  
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    'Cleanup {'(8<n5
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    ClearOutputWindow() 70eN]OY  
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    Print "Merging RPC Photonics BSDF Data Files" Is
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    SetTextColor(255,0,0) 7&1: ]{_  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." htaLOTO;A  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." rg\w!L(  
    SetTextColor(0,0,0) 0M?}S~p]  
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    'Current directory of this script (should be the same as the text files being merged) mr? ii  
    Dim cDir As String %+~0+ev7r  
    cDir = MacroDir$ & "\" |~Iw  
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    'Array which will be populated with the list of files to be merged WW=7QCi  
    Dim fList() As String, curFile As String v#xF;@G  
    GetFileList( cDir, fList ) =_Rd0,  
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    Print "" 9 pn1d.  
    Print "Files found for merging:" |1o]d$3m  
    For Each curFile In fList 4tjRju?  
        Print Chr(9) & curFile p WHu[Fu  
    Next 6%-2G@6d  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. R#>E{[9  
    Dim nameArray() As String, sampName As String z~qQ@u|  
    nameArray = Split(fList(0)," 0-0.txt") _[W=1bGJ  
    sampName  = nameArray(0) -/X-.#}-  
    Print "" \=)h6AG  
    Print "Sample name: " & Chr(9) & sampName {$^|^n5j  
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    'Open an output file and write the FRED header data P;34Rd  
    Dim outFile As String gK /K Z8  
    outFile = cDir & sampName & "_FRED.txt" 7+"X^$  
    Open outFile For Output As #1 {8Ll\j@ "  
    Print #1, "type bsdf_data" `m5iZxhw  
    Print #1, "format angles=deg bsdf=value scale=1" 0U'r ia:$  
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    'Loop the file list, skip the two header lines and write the remaining data to file |dK-r  
    Dim lineArray() As String, curLine As Long Hg4Ut/0  
    For Each curFile In fList 2k_Bo~.  
        Print "Merging data from file " & curFile c1i7Rc{q  
        ReadFile( cDir & curFile, lineArray ) f$
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        For curLine = 2 To UBound(lineArray) `8I&(k<wLe  
            Print #1, lineArray(curLine) l-&f81W  
        Next F3q5!1  
    Next  DWI!\lK  
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    'Close the output file ag6S"IXh  
    Close #1 yAOC<d9 E  
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    Print "Finished merging RPC data for sample " & sampName ?~!h N,h  
    Print "FRED formatted data file: " & Chr(9) & outFile X^ovP'c2  
End Sub Xp'KQ1w)  
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'Utility function to read the contents of a file into an array of strings. 2rxdRg'YLQ  
Function ReadFile(ByVal fileName As String, _ sb1/4u/W  
                  ByRef lineArray() As String) As Long ;.Kzc3yz}  
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    ReadFile = -1 q~qig,$Y  
    Dim oFSO As Object \vI_%su1N  
    Set oFSO = CreateObject("Scripting.FileSystemObject")  m ]\L1&  
    Erase lineArray bnlL-]]9z  
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    Dim fid As Long IAfYlS#<yD  
    If oFSO.fileexists( fileName ) Then |:\h3M  
        fid = FreeFile() hm&~6rB  
        Open fileName For Input As fid .}tL:^'~o  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Z5\6ca  
        Close fid "-a>Uj")%  
    End If 8)i\d`  
    Set oFSO = Nothing ?mV[TM{p  
    Return UBound( lineArray ) ]SQ_*$`  
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End Function 9DIGK\  
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Sub GetFileList( ByVal in_dir As String, _ 3yTBkFI!  
                 ByRef in_flist() As String ) {Z|C  
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    'Redimension the file list array "PX~Yc  
    Erase in_flist /(q*  
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    'Tracks how many files are found 4o%hH  
    Dim fCount As Long 8'zwyd3  
    fCount = 0 @FQ@*XD  
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    'Recurse directory and search for text files 2-$R@ SVy  
    Dim f As String 4F'@yi^Gt  
    f = Dir$(in_dir & "*.txt") '8dqJ`Gj  
    While f <> "" }%VHBkuc  
        ReDim Preserve in_flist(fCount) 7|{QAv  
        in_flist(fCount) = f f`?|A  
        fCount += 1 C}M0KDF  
        f = Dir$() Fr3Q"(  
    Wend m8FKr/Z-  
    ReDim Preserve in_flist(fCount-1) KVK@Snn   
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End Sub }+SnY8A=KZ