[分享]RPC Photonics扩散片BSDF [复制链接]

摘要： W_z2Fs"A  
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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。 d8 1u  
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背景： _sU|<1  
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。 0>#or$:6E  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 *&VH!K#@{  
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步骤 L,Jl# S  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 }{Y)[w#R  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） ["|' f  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 #BQ7rF7CNE  
例如下所示： hQ!slO  
Sample name:  EDF-C1-56 y~)rZ-eSB  
Merging data from file EDF-C1-56 0-0.txt F.P4
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Finished merging RPC data for sample EDF-C1-56 hX#s3)87  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt n-m+@jRz  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 o
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a. 创建一个新的散射库 ^4@~\#$z  
b. 散射模型命名 G5y>v^&H  
c. 改变散射模型为“Tabulated BSDF”. #E`-b9Q  
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 ） R["2kEF  
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。 :+;AXnDM~  
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， ?haN ;n6'  
g. 点击OK 8y;W+I(71  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 l"%|VWZ{iq  
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脚本代码： 9z9z
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'#Language "WWB-COM" m=&j2~<i  
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Option Explicit uPk`9c52%  
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Sub Main ~YO-GX(  
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    'Cleanup k|W=kt$P  
    ClearOutputWindow() 6 W/S?F~{  

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    Print "Merging RPC Photonics BSDF Data Files" !4uTi [e  
    SetTextColor(255,0,0) xao'L  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." T.kmoLlH  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." wCiDvHF5+C  
    SetTextColor(0,0,0) (p<
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    'Current directory of this script (should be the same as the text files being merged) `_Bvaej?,  
    Dim cDir As String }J}a;P4  
    cDir = MacroDir$ & "\" 4`@]jm  
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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 *<*{gO?Q4
 
    GetFileList( cDir, fList ) -|^}~yOx0=  
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    Print "" Dt,b\6  
    Print "Files found for merging:" }^uUw&   
    For Each curFile In fList E@\e37e  
        Print Chr(9) & curFile @xR7>-$0p  
    Next m7X&"0X  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. <VV./W8e9  
    Dim nameArray() As String, sampName As String Q!/<=95E  
    nameArray = Split(fList(0)," 0-0.txt") U,"lOG'  
    sampName  = nameArray(0) %zE_Q  
    Print "" <{@?c  
    Print "Sample name: " & Chr(9) & sampName $Gb] K{e  
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    'Open an output file and write the FRED header data c^P8)gPf  
    Dim outFile As String ^.Cfa  
    outFile = cDir & sampName & "_FRED.txt" 2SU G/-P#  
    Open outFile For Output As #1 bF %#KSVw  
    Print #1, "type bsdf_data" {<~0nLyJS  
    Print #1, "format angles=deg bsdf=value scale=1" "sF&WuW|  
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    'Loop the file list, skip the two header lines and write the remaining data to file 2V
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    Dim lineArray() As String, curLine As Long ~Nf01,F  
    For Each curFile In fList \dj&4u3  
        Print "Merging data from file " & curFile ?&Si P-G  
        ReadFile( cDir & curFile, lineArray ) @`2<^-r\  
        For curLine = 2 To UBound(lineArray) q[{q3-W  
            Print #1, lineArray(curLine) r,=xI`XH  
        Next !cnunLc`  
    Next _3<J!$]&p  
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    'Close the output file ,Iq+v  
    Close #1 u2K{3+r`'  
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    Print "Finished merging RPC data for sample " & sampName NL&(/72V  
    Print "FRED formatted data file: " & Chr(9) & outFile q@;WXHO0  
End Sub `we2zT  
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'Utility function to read the contents of a file into an array of strings. .!0),KmkK  
Function ReadFile(ByVal fileName As String, _ vC~];!^  
                  ByRef lineArray() As String) As Long M= !Fb  
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    ReadFile = -1 p,}-8#K[  
    Dim oFSO As Object
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    Set oFSO = CreateObject("Scripting.FileSystemObject") `L`*jA+_  
    Erase lineArray 9 m&"x/k  
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    Dim fid As Long 9,Zg'4",d  
    If oFSO.fileexists( fileName ) Then x P{L%.  
        fid = FreeFile() #C,M8~Q7  
        Open fileName For Input As fid `Bx3grZ 7&  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ug[|'tR8  
        Close fid {55{YDqx  
    End If /_v5B>  
    Set oFSO = Nothing %lz\w{  
    Return UBound( lineArray ) _Hi;Y  
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End Function .6SdSB^M  
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Sub GetFileList( ByVal in_dir As String, _ 7a0ZI  
                 ByRef in_flist() As String ) [CBA Lj5  
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    'Redimension the file list array `;WiTE)&)  
    Erase in_flist Nkn0G_  
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    'Tracks how many files are found QE}S5#_"  
    Dim fCount As Long uSbOGhP  
    fCount = 0 m8$6FN  
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    'Recurse directory and search for text files X!&DKE  
    Dim f As String 0z/tceW'F  
    f = Dir$(in_dir & "*.txt") B1c`(mHl  
    While f <> "" <`5>;Xn=  
        ReDim Preserve in_flist(fCount) eS fT+UL  
        in_flist(fCount) = f ('Wo#3b$  
        fCount += 1 k:s}`h_n  
        f = Dir$() YQ X+lE  
    Wend {"!V&}
 
    ReDim Preserve in_flist(fCount-1) f7{E(,  
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End Sub ?XL[[vyr  
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