[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： S[_Hc$7U  
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RPC Photonics公司有高品质的的工程漫射体BSDF测试数据，但它对于FRED帮助甚少，下面这个步骤描述了如何利用FRED脚本转换RPC Photonics提供的TXT文件，并将数据直接应用到FRED的Tabulated scatter 散射模型。 |RdiM&C7  
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背景： =u+.o<  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 5X'com?T  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 DW,fh8w  
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步骤 9kkYD  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 p(5'|eqBV  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） &;)6G1X1  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 u}[Z=V  
例如下所示： &>!WhC16  
Sample name:  EDF-C1-56 <^Hh5kfS'  
Merging data from file EDF-C1-56 0-0.txt h2Pvj37  
Finished merging RPC data for sample EDF-C1-56 dB^')-wA  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt p4|Zz:f  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 r}gp{Pf7e  
a. 创建一个新的散射库 <( 0TK5  
b. 散射模型命名 3j2% '$>E^  
c. 改变散射模型为“Tabulated BSDF”. (aO+7ykRuJ  
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 ） $g|/.XH%  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 o~I
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f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， oXR%A7  
g. 点击OK ,a I0Aw  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 /FZ@Z]Q0G  
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脚本代码： LZ@4,Uj  
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'#Language "WWB-COM" GUe&WW:Sqk  
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Option Explicit iG[an*#X  
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Sub Main 8bB'[gJ]{  
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    'Cleanup Vm1U00lM{  
    ClearOutputWindow() &k5 Z
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    Print "Merging RPC Photonics BSDF Data Files" Q6cF<L`bW  
    SetTextColor(255,0,0) &oWdBna"_  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." F:8cd^d~u  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ~PT(/L  
    SetTextColor(0,0,0) T/%s7!E  
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    'Current directory of this script (should be the same as the text files being merged) W@^O'&3d  
    Dim cDir As String cTKj1)!z?X  
    cDir = MacroDir$ & "\" %} _{_Z  
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    'Array which will be populated with the list of files to be merged =NH p%|  
    Dim fList() As String, curFile As String ( _ZOUMe  
    GetFileList( cDir, fList ) rZDmZm?=  
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    Print "" 1)aB']K%  
    Print "Files found for merging:" ,H3~mq]  
    For Each curFile In fList =<.8  
        Print Chr(9) & curFile npH2&6Yhi^  
    Next oEE*H2l\  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. R4<}kA,.  
    Dim nameArray() As String, sampName As String r^?Qo  
    nameArray = Split(fList(0)," 0-0.txt") s|U=_,.  
    sampName  = nameArray(0) TR8
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    Print "" 6xs_@Vk|d  
    Print "Sample name: " & Chr(9) & sampName pJ6Z/
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    'Open an output file and write the FRED header data ;zD1#dD
 
    Dim outFile As String a_YE[6  
    outFile = cDir & sampName & "_FRED.txt" *dn~-W.  
    Open outFile For Output As #1 .0:twj  
    Print #1, "type bsdf_data" &46h!gW  
    Print #1, "format angles=deg bsdf=value scale=1" D7b<&D@  
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    'Loop the file list, skip the two header lines and write the remaining data to file n|vIo)  
    Dim lineArray() As String, curLine As Long KZ/U2.{O<  
    For Each curFile In fList 1&~u:RUXe  
        Print "Merging data from file " & curFile :,$:@  
        ReadFile( cDir & curFile, lineArray ) 9-Bp=M  
        For curLine = 2 To UBound(lineArray) W'2|hP  
            Print #1, lineArray(curLine) O_#Ag K<A  
        Next !HM|~G7  
    Next '~{^c}  
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    'Close the output file oagxTFh8~  
    Close #1 /sf:.TpVh  
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    Print "Finished merging RPC data for sample " & sampName >&m
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    Print "FRED formatted data file: " & Chr(9) & outFile CwQgA%)!i  
End Sub MR/jM@8  
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'Utility function to read the contents of a file into an array of strings. F#KO!\iA+  
Function ReadFile(ByVal fileName As String, _ D!kv+<+  
                  ByRef lineArray() As String) As Long 4oT1<n`r+  
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    ReadFile = -1 wSHE~Xx  
    Dim oFSO As Object r>1M&Y=<  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 0 !yvcviw  
    Erase lineArray Qi',[Xmf  
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    Dim fid As Long tuuc9H4B  
    If oFSO.fileexists( fileName ) Then .L[WvAo  
        fid = FreeFile() _D:#M  
        Open fileName For Input As fid L;=:OX0  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) {dV#"+  
        Close fid c#M'Mye  
    End If ]q DhGt  
    Set oFSO = Nothing vr<6j/ty  
    Return UBound( lineArray ) :B?X
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End Function \xi wp.  
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Sub GetFileList( ByVal in_dir As String, _ K^bzZa+a  
                 ByRef in_flist() As String ) _4iTP$7[  
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    'Redimension the file list array jA R@?X  
    Erase in_flist 8munw  
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    'Tracks how many files are found _IJPZ'Hr  
    Dim fCount As Long = R|?LOEK+  
    fCount = 0 mRB-}  
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    'Recurse directory and search for text files ^~Nz8PCY  
    Dim f As String {7&(2Z]z  
    f = Dir$(in_dir & "*.txt") K*Y.mM)  
    While f <> "" n.]K"$230  
        ReDim Preserve in_flist(fCount) `T2RaWR4=  
        in_flist(fCount) = f [O
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        fCount += 1 8`Fo^c=j  
        f = Dir$() 59gt#1k  
    Wend 6>ZUx}vYj  
    ReDim Preserve in_flist(fCount-1) Ql sMMIax  
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End Sub 6r/NdI