OpenGL glLookAt用于任意视点

Question

I am computing a model centroid using the min max vertex values, for all objects in the scene and now I want to rotate and look at it from an arbitrary viewpoint looking at the centroid.

Has someone does this with glLookAt() ? I am using Perspective mode.

Answer 1

Look at the docs for gluLookAt(). What you want to do is exactly what this function does. gluLookat creates the View matrix, so it should be:

glMatrixMode(GL_MODELVIEW); 
glLoadIdentity();
gluLookAt(eyeX, eyeY, eyeZ, centerX, centerY, centerZ, upX, upY, upZ);

The projection matrix sets the clipping planes:

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(left, right, bottom, top, near, far);

or

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(fovDegrees, aspectRatio, near, far);