lgc_ustc

01-02-2004, 12:11 AM

Hello, fellas,

I have been brooding on the problem for three days, it's like:

I am using gluLookAt to position the camera in the world space, which will change the current model/view matrix, I think. Since I read some tutorials and they said so. In my notion, the position of camera is related to the model/view matrix and the fov/ration is related to the projection matrix. However, after I called the gluLookAt function, the projection matrix is changed but the model/view matrix remains unchanged! Well, this seems that the gluLookAt function uses the projection matrix to do all the camera things and has nothing to do with the model/view matrix. Another paper on the internet make me tend to believe this rather than my original thought: http://www.acm.jhu.edu/~upe/member_sites/duca/node6.html

Am I correct? If so, another way to control the camera seems easier to me: the reverse matrix of the camera position is constructed and then applied to the scene.

Thanks for any replies clarifying my confusions on camera control, and HAPPY NEW YEAR TO YOU ALL http://www.opengl.org/discussion_boards/ubb/smile.gif

I have been brooding on the problem for three days, it's like:

I am using gluLookAt to position the camera in the world space, which will change the current model/view matrix, I think. Since I read some tutorials and they said so. In my notion, the position of camera is related to the model/view matrix and the fov/ration is related to the projection matrix. However, after I called the gluLookAt function, the projection matrix is changed but the model/view matrix remains unchanged! Well, this seems that the gluLookAt function uses the projection matrix to do all the camera things and has nothing to do with the model/view matrix. Another paper on the internet make me tend to believe this rather than my original thought: http://www.acm.jhu.edu/~upe/member_sites/duca/node6.html

Am I correct? If so, another way to control the camera seems easier to me: the reverse matrix of the camera position is constructed and then applied to the scene.

Thanks for any replies clarifying my confusions on camera control, and HAPPY NEW YEAR TO YOU ALL http://www.opengl.org/discussion_boards/ubb/smile.gif