<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>I have a project where I am using the cursor keys and Page Up/Down to do camera yaw, pitch, and dolly. The comments for Dolly in vtkCamera is<BR>
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<B><I> // Description:<BR>
// Move the position of the camera along the direction of projection. Moving<BR>
// towards the focal point (e.g., greater than 1) is a dolly-in, moving away <BR>
// from the focal point (e.g., less than 1) is a dolly-out.<BR>
void Dolly(double distance);</B></I><BR>
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Also, according to the description of Dolly in the VTK book (2nd edition) <B><I>Dollying in and out should move the camer's positon along the direction of the focal point. </B></I><BR>
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I take it that the focal point remains the same while the distance from it and the camera gets shorter or longer (dollying in or out).<BR>
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So, If I want to preserve my focal length, do I have to change both the focal point and the position of the camera as it moves throughout three space?<BR>
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Thanks friends!<BR>
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George<BR>
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<B>George C. Harrison Professor of Computer Science<BR>
Norfolk State University</B><BR>
Telephone: 757-823-8654<BR>
Fax: 757-823-9229<BR>
email: gharrison9@aol.com<BR>
or gcharrison@nsu.edu (same difference..)</FONT></HTML>