[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： )bPwB.}kq  
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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。 Q]a5]:0  
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背景： A3!NEFBK  
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。 &=@R,  
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。 B~yD4^  
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步骤 ~8}"X] 4  
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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。 F#Z]Xq0r  
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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） lT1*e(I  
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 1[u{3lQ  
例如下所示： VO. Y\8/  
Sample name:  EDF-C1-56 + +D(P=4hi  
Merging data from file EDF-C1-56 0-0.txt x/bO;9E%U4  
Finished merging RPC data for sample EDF-C1-56 6Q>:g"_  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt .:l78>f  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 PN+,M50;1  
a. 创建一个新的散射库 3_vggK%  
b. 散射模型命名 Kze\|yJ  
c. 改变散射模型为“Tabulated BSDF”. )1lYfJ  
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 ） oV,>u5:B  
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。 pd>EUdbrp&  
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， 78y4nRQ*  
g. 点击OK [<8<+lH=P  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 )k0bP1oGS  
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脚本代码： *kZJ  
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'#Language "WWB-COM" B@.U\.  
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Option Explicit mZMLDs:  
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Sub Main -%%2Pz0I  
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    'Cleanup X(g<rz1J]  
    ClearOutputWindow()
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    Print "Merging RPC Photonics BSDF Data Files" ,f}s!>j  
    SetTextColor(255,0,0) cnhYrX^  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." IBnJ6(.  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 0#XZ_(@%  
    SetTextColor(0,0,0) {IqbO>|"O_  
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    'Current directory of this script (should be the same as the text files being merged) #UI@<0P)  
    Dim cDir As String Ex
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    cDir = MacroDir$ & "\" 0Oe@0L%^3"  
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    'Array which will be populated with the list of files to be merged }3M\&}=8  
    Dim fList() As String, curFile As String u_zp?Nc  
    GetFileList( cDir, fList ) +4B>gS[ F  
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    Print "" U2@?!B[\d`  
    Print "Files found for merging:" \CU.'|X  
    For Each curFile In fList *<s|WLMG  
        Print Chr(9) & curFile Y 1LE.{  
    Next 6 )xm?RK  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. >|uZIcs 6  
    Dim nameArray() As String, sampName As String =;^2#UxXA&  
    nameArray = Split(fList(0)," 0-0.txt") .i
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    sampName  = nameArray(0) M^k~w{   
    Print "" kA
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    Print "Sample name: " & Chr(9) & sampName >qAQNX  
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    'Open an output file and write the FRED header data *jf (TIU  
    Dim outFile As String #Z (B4YO  
    outFile = cDir & sampName & "_FRED.txt" k((_~<$2K  
    Open outFile For Output As #1 :|N5fkhN  
    Print #1, "type bsdf_data" ;]vE"Mx$  
    Print #1, "format angles=deg bsdf=value scale=1" ks 3<zW(  
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    'Loop the file list, skip the two header lines and write the remaining data to file g^4'42UX  
    Dim lineArray() As String, curLine As Long n#bC,  
    For Each curFile In fList u@[D*c1!H  
        Print "Merging data from file " & curFile 0alm/or  
        ReadFile( cDir & curFile, lineArray ) dJ:EXVU  
        For curLine = 2 To UBound(lineArray) dhsQfWg#}  
            Print #1, lineArray(curLine) ~qco -b  
        Next <_ddGg~  
    Next u= !?<Q  
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    'Close the output file ?5jkb  
    Close #1 Pou`PNvH  
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    Print "Finished merging RPC data for sample " & sampName 1i#M(u_  
    Print "FRED formatted data file: " & Chr(9) & outFile j`='SzVloW  
End Sub 4~DFtWbf  
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'Utility function to read the contents of a file into an array of strings. O .m;a_  
Function ReadFile(ByVal fileName As String, _ |4ONGU*`E  
                  ByRef lineArray() As String) As Long bC)diC  
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    ReadFile = -1 vX/~34o]\  
    Dim oFSO As Object >&Y8
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    Set oFSO = CreateObject("Scripting.FileSystemObject") Rco#?'  
    Erase lineArray g}P.ksM  
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    Dim fid As Long UIovv%7zZ  
    If oFSO.fileexists( fileName ) Then V!a\:%#^Y  
        fid = FreeFile() YRAWylm  
        Open fileName For Input As fid
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 28>gAz.#  
        Close fid H'&x
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    End If i|)<#Ywl  
    Set oFSO = Nothing (9{)4[3MAG  
    Return UBound( lineArray ) 11Pm lzy  
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End Function .@gv}`>  
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Sub GetFileList( ByVal in_dir As String, _ Qpe&_.&RE  
                 ByRef in_flist() As String ) Ca0~K42~  
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    'Redimension the file list array Z Z\,iT  
    Erase in_flist }{J<Wzw  
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    'Tracks how many files are found {^1D|y  
    Dim fCount As Long #\GWYWkR  
    fCount = 0 8^CL:8lI^\  
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    'Recurse directory and search for text files sFT-aLpL@V  
    Dim f As String :1PT`:Y  
    f = Dir$(in_dir & "*.txt") 4 B"tz!  
    While f <> "" Fi14_{  
        ReDim Preserve in_flist(fCount) ))K3pKyb  
        in_flist(fCount) = f H3H3UIIT_  
        fCount += 1 N~=p+Ow[H  
        f = Dir$() -WWa`,:  
    Wend ^dJ/>?1  
    ReDim Preserve in_flist(fCount-1) t$m268m~  
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End Sub XkDjA#nx`