[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： "i!W(}x+  
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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。 ?}C8_I|4~  
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背景： VuH}@  
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。 ~x J#NC+  
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。 VY@`)  
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步骤 VI.Cmw~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。 )H&ZHaO,_  
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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） S5cs(}Bq  
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 H<qz rO  
例如下所示： hl,x|.f}4Y  
Sample name:  EDF-C1-56 vI(CX]o  
Merging data from file EDF-C1-56 0-0.txt nr&9\lG]G  
Finished merging RPC data for sample EDF-C1-56 '1Ex{

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FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 9q2x}  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 /KlSI<T@  
a. 创建一个新的散射库 HYNpvK  
b. 散射模型命名 1([?EfC  
c. 改变散射模型为“Tabulated BSDF”. _znpzr9H  
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 ） unr`.}A2>  
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。 QO4eDSW  
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， pQ8f$I#v  
g. 点击OK }3-`e3  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 t;y@;?~
 
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脚本代码： ~^o YPd52*  
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'#Language "WWB-COM" {k']nI.>  
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Option Explicit ];QX&";Z  
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Sub Main "_\77cqpTh  
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    'Cleanup ] B>.}  
    ClearOutputWindow() LE g#W  
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    Print "Merging RPC Photonics BSDF Data Files" U \F ?{/  
    SetTextColor(255,0,0) gi8f)MNP?~  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." bq{eu#rQJ  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Mp@dts/|  
    SetTextColor(0,0,0) A!a.,{fZ  
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    'Current directory of this script (should be the same as the text files being merged) bFJ>+ {#  
    Dim cDir As String r$,Xv+}  
    cDir = MacroDir$ & "\" W}WDj:  
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    'Array which will be populated with the list of files to be merged 2
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    Dim fList() As String, curFile As String 2hb>6Z;r]K  
    GetFileList( cDir, fList ) D<T:UJ  
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    Print "" 0 l
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    Print "Files found for merging:" 6N/6WrQEeg  
    For Each curFile In fList y`pgJO  
        Print Chr(9) & curFile N\fj[?f[  
    Next tl=e!  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Hr*xAx  
    Dim nameArray() As String, sampName As String *~zB{  
    nameArray = Split(fList(0)," 0-0.txt") W O'nW  
    sampName  = nameArray(0) &HqBlRo  
    Print "" \ns} M3  
    Print "Sample name: " & Chr(9) & sampName +O7GgySx  
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    'Open an output file and write the FRED header data i`!>zl+D  
    Dim outFile As String $IJ"fs  
    outFile = cDir & sampName & "_FRED.txt" )vGxF}I3  
    Open outFile For Output As #1 lXutZ<S[  
    Print #1, "type bsdf_data" h~ehZJys  
    Print #1, "format angles=deg bsdf=value scale=1" eo&G@zwN  
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    'Loop the file list, skip the two header lines and write the remaining data to file q( %)^C  
    Dim lineArray() As String, curLine As Long z#6(PZC}  
    For Each curFile In fList ?',GRaD  
        Print "Merging data from file " & curFile Y,-!QFS#  
        ReadFile( cDir & curFile, lineArray ) Xj<xen(  
        For curLine = 2 To UBound(lineArray) <ti,Wn.  
            Print #1, lineArray(curLine) ./
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        Next :,.HJ[Vg&  
    Next FMT_X  
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    'Close the output file EU'P U  
    Close #1 =Nr?
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    Print "Finished merging RPC data for sample " & sampName oKPG0iM:  
    Print "FRED formatted data file: " & Chr(9) & outFile hwSxdT6  
End Sub 43*;"w=  
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'Utility function to read the contents of a file into an array of strings. cvjZ$Fcc%(  
Function ReadFile(ByVal fileName As String, _ VwT&A9&{8  
                  ByRef lineArray() As String) As Long ^$y`Q@-9  
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    ReadFile = -1 96%N  
    Dim oFSO As Object }-p-(  
    Set oFSO = CreateObject("Scripting.FileSystemObject") )Dyyb1\)  
    Erase lineArray L#N]1#;  
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    Dim fid As Long M`?ATmYy  
    If oFSO.fileexists( fileName ) Then Q'aVdJN,  
        fid = FreeFile() pbGv\SF  
        Open fileName For Input As fid fbJa$  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) m>!aI?g  
        Close fid soA] f  
    End If :#=BwdC  
    Set oFSO = Nothing \OkJX_7  
    Return UBound( lineArray ) CT(HTu  
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End Function w^[:wzF0  
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Sub GetFileList( ByVal in_dir As String, _ A%~t[
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                 ByRef in_flist() As String ) 5qkyi]/U8  
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    'Redimension the file list array 0RN7hpf&`  
    Erase in_flist z h%b<  
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    'Tracks how many files are found -$`q:j  
    Dim fCount As Long BipD8`a  
    fCount = 0 g>{t>B%v^K  
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    'Recurse directory and search for text files 0,6!6>BOT  
    Dim f As String v1 f^gde  
    f = Dir$(in_dir & "*.txt") )2R]KU_=g  
    While f <> "" bUc++M
 
        ReDim Preserve in_flist(fCount) o)H| #9h5  
        in_flist(fCount) = f NFI~vkk'G  
        fCount += 1 tD]vx`0>  
        f = Dir$() q0@b d2}  
    Wend !ozHS_  
    ReDim Preserve in_flist(fCount-1) E>F6!q
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End Sub ?]>;Wr