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Because Azimuth is a movement whilst Roll is an intrinsic property of the camera?<BR>
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Azimuth is dependent on the entire setting. e.g, if you Azimuth +90, change the focal point, and Azimuth -90, you may not get to your original position.<BR><BR>Xiaofeng Zhao<BR><A href="http://www.xzing.org/" target=_blank>http://www.xzing.org</A> <BR>errare humanum est<BR><BR><BR><BR>
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From: huameichen0523@gmail.com<BR>To: xf10036@hotmail.com; vtkusers@vtk.org<BR>Subject: Re: [vtkusers] How to set a camera's azimuth and elevation?<BR>Date: Wed, 1 Oct 2008 05:17:56 -0500<BR><BR><BR>
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<DIV><FONT face=Arial>Xiaofeng and all,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I am sorry that the question I raised was not clear. Basically what I wanted to achieve was to reset the camera's original position. The methods vtkCamera::Azimuth() , vtkCamera::Elevation() and vtkCamera::Roll() won't do the job unless I keep tracking how much the camera has rotated about the three axes. For example, the following code results a roll angle 90, not 0.</FONT></DIV>
<DIV><FONT face=Arial>camera->Roll(30);</FONT></DIV>
<DIV><FONT face=Arial>camera->Roll(60);</FONT></DIV>
<DIV><FONT face=Arial>camera->Roll(0);</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>However, the following code does result in a roll angle 0.</FONT></DIV>
<DIV><FONT face=Arial>camera->Roll(30);</FONT></DIV>
<DIV><FONT face=Arial>camera->Roll(60);</FONT></DIV>
<DIV><FONT face=Arial>camera->SetRoll(0);</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>My question was why there is no similar SetAzimuth() and SetElevation() methods in the class vtkCamera() and how to achieve my goal using other methods easily.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Thank you.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Chen</FONT></DIV>
<DIV><FONT face=Arial> </FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=xf10036@hotmail.com href="mailto:xf10036@hotmail.com">Xiaofeng Z</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=huameichen0523@gmail.com href="mailto:huameichen0523@gmail.com">Hua-Mei Chen</A> ; <A title=vtkusers@vtk.org href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, September 30, 2008 11:07 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [vtkusers] How to set a camera's azimuth and elevation?</DIV>
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<TD class=EC_memname>Azimuth:<BR> <BR>void vtkamera::Azimuth <BR></TD>
<TD>(</TD>
<TD class=EC_paramtype>double </TD>
<TD class=EC_paramname><EM>angle</EM> </TD>
<TD> )<BR> <BR></TD>
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<DIV class=EC_memdoc>Rotate the camera about the view up vector centered at the focal point. Note that the view up vector is not necessarily perpendicular to the direction of projection. <BR><BR>Xiaofeng Zhao<BR><A href="http://www.xzing.org/" target=_blank>http://www.xzing.org</A> <BR>errare humanum est<BR><BR><BR>
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From: <A href="mailto:huameichen0523@gmail.com">huameichen0523@gmail.com</A><BR>To: <A href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</A><BR>Date: Tue, 30 Sep 2008 14:46:29 -0500<BR>Subject: [vtkusers] How to set a camera's azimuth and elevation?<BR><BR>
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<DIV>Hi all,</DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> I am wondering how to set a camera's azimuth and elevation. There is a SetRoll() method in vtkCamera to set the roll of a camera. However, no similar methods exist for setting the azimuth and elevation. Does anyone know why? And how do I achieve my goal using other methods? Thank you.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Chen</FONT></DIV></FONT></DIV>
<DIV> </DIV><BR>
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