Camera Rotation aka "Beating head against wall"

BrokenNails · 2004-06-04T02:26:02

RTS style here. Trying to rotate the camera about the vertical axis (Z in my case) while staying focussed on a single point (ie the camera and it''s direct line of sight to a point on the terrain would carve out a lovely cone shape when doing a full rotation). Camera implemented using the standard 3 vectors (eye, lookAt, and up). Anyway, I thought the following pseudo code (I''m at work so pseudo''s all I''ve got) was what I was after, but it only works when the lookAt vector is at the origin. If it''s not then things tend to rotate in an odd fashion: (a, b, and c are matrices) a = Translate(new Vector3(0,0,0) - lookat_vector) //translate back to the origin b = RotateZ(angle) // Rotate about vertical (z) axis c = Translate(lookat_vector) //translate back to original position eye_vector.transform(a * b * c) up_vector.transform(a * b * c) Is there something blindingly obvious I''m doing wrong here? I think I''m beyond the point where I am thinking rationally... :-)

Graphics and GPU Programming Programming

Started by BrokenNails June 03, 2004 02:37 PM

9 comments, last by BrokenNails 19 years, 10 months ago

BrokenNails

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June 04, 2004 02:26 AM

Got home, removed the translation matrices from the up_vector rotation and it all works. Seems so obvious now, but I guess that''s how it goes sometimes...

Thanks for all your help everyone!

Camera Rotation aka "Beating head against wall"

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Camera Rotation aka "Beating head against wall"

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